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PostgreSQL/src/backend/partitioning/partprune.c
Alvaro Herrera 8f97af60d1 Consistently use the term 'partitioned rel' in partprune comments 
We were using 'partition rel' in a few places, which is quite confusing.

Author: Amit Langote
Reviewed-by: David Rowley
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/fd256561-31a2-4b7e-cd84-d8241e7ebc3f@lab.ntt.co.jp
2018-06-20 11:43:01 -04:00

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/*-------------------------------------------------------------------------
*
* partprune.c
* Support for partition pruning during query planning and execution
*
* This module implements partition pruning using the information contained in
* a table's partition descriptor, query clauses, and run-time parameters.
*
* During planning, clauses that can be matched to the table's partition key
* are turned into a set of "pruning steps", which are then executed to
* identify a set of partitions (as indexes in the RelOptInfo->part_rels
* array) that satisfy the constraints in the step. Partitions not in the set
* are said to have been pruned.
*
* A base pruning step may involve expressions whose values are only known
* during execution, such as Params, in which case pruning cannot occur
* entirely during planning. In that case, such steps are included alongside
* the plan, so that they can be used by the executor for further pruning.
*
* There are two kinds of pruning steps. A "base" pruning step represents
* tests on partition key column(s), typically comparisons to expressions.
* A "combine" pruning step represents a Boolean connector (AND/OR), and
* combines the outputs of some previous steps using the appropriate
* combination method.
*
* See gen_partprune_steps_internal() for more details on step generation.
*
* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/partitioning/partprune.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/hash.h"
#include "access/nbtree.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/pathnode.h"
#include "optimizer/planner.h"
#include "optimizer/predtest.h"
#include "optimizer/prep.h"
#include "optimizer/var.h"
#include "partitioning/partprune.h"
#include "partitioning/partbounds.h"
#include "rewrite/rewriteManip.h"
#include "utils/lsyscache.h"
/*
* Information about a clause matched with a partition key.
*/
typedef struct PartClauseInfo
{
int keyno; /* Partition key number (0 to partnatts - 1) */
Oid opno; /* operator used to compare partkey to expr */
bool op_is_ne; /* is clause's original operator <> ? */
Expr *expr; /* expr the partition key is compared to */
Oid cmpfn; /* Oid of function to compare 'expr' to the
* partition key */
int op_strategy; /* btree strategy identifying the operator */
} PartClauseInfo;
/*
* PartClauseMatchStatus
* Describes the result of match_clause_to_partition_key()
*/
typedef enum PartClauseMatchStatus
{
PARTCLAUSE_NOMATCH,
PARTCLAUSE_MATCH_CLAUSE,
PARTCLAUSE_MATCH_NULLNESS,
PARTCLAUSE_MATCH_STEPS,
PARTCLAUSE_MATCH_CONTRADICT,
PARTCLAUSE_UNSUPPORTED
} PartClauseMatchStatus;
/*
* GeneratePruningStepsContext
* Information about the current state of generation of "pruning steps"
* for a given set of clauses
*
* gen_partprune_steps() initializes an instance of this struct, which is used
* throughout the step generation process.
*/
typedef struct GeneratePruningStepsContext
{
int next_step_id;
List *steps;
} GeneratePruningStepsContext;
/* The result of performing one PartitionPruneStep */
typedef struct PruneStepResult
{
/*
* The offsets of bounds (in a table's boundinfo) whose partition is
* selected by the pruning step.
*/
Bitmapset *bound_offsets;
bool scan_default; /* Scan the default partition? */
bool scan_null; /* Scan the partition for NULL values? */
} PruneStepResult;
static List *gen_partprune_steps(RelOptInfo *rel, List *clauses,
bool *contradictory);
static List *gen_partprune_steps_internal(GeneratePruningStepsContext *context,
RelOptInfo *rel, List *clauses,
bool *contradictory);
static PartitionPruneStep *gen_prune_step_op(GeneratePruningStepsContext *context,
StrategyNumber opstrategy, bool op_is_ne,
List *exprs, List *cmpfns, Bitmapset *nullkeys);
static PartitionPruneStep *gen_prune_step_combine(GeneratePruningStepsContext *context,
List *source_stepids,
PartitionPruneCombineOp combineOp);
static PartitionPruneStep *gen_prune_steps_from_opexps(PartitionScheme part_scheme,
GeneratePruningStepsContext *context,
List **keyclauses, Bitmapset *nullkeys);
static PartClauseMatchStatus match_clause_to_partition_key(RelOptInfo *rel,
GeneratePruningStepsContext *context,
Expr *clause, Expr *partkey, int partkeyidx,
bool *clause_is_not_null,
PartClauseInfo **pc, List **clause_steps);
static List *get_steps_using_prefix(GeneratePruningStepsContext *context,
StrategyNumber step_opstrategy,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix);
static List *get_steps_using_prefix_recurse(GeneratePruningStepsContext *context,
StrategyNumber step_opstrategy,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
int step_lastkeyno,
Bitmapset *step_nullkeys,
ListCell *start,
List *step_exprs,
List *step_cmpfns);
static PruneStepResult *get_matching_hash_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum *values, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys);
static PruneStepResult *get_matching_list_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum value, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys);
static PruneStepResult *get_matching_range_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum *values, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys);
static Bitmapset *pull_exec_paramids(Expr *expr);
static bool pull_exec_paramids_walker(Node *node, Bitmapset **context);
static bool analyze_partkey_exprs(PartitionPruneInfo *pinfo, List *steps,
int partnatts);
static PruneStepResult *perform_pruning_base_step(PartitionPruneContext *context,
PartitionPruneStepOp *opstep);
static PruneStepResult *perform_pruning_combine_step(PartitionPruneContext *context,
PartitionPruneStepCombine *cstep,
PruneStepResult **step_results);
static bool match_boolean_partition_clause(Oid partopfamily, Expr *clause,
Expr *partkey, Expr **outconst);
static bool partkey_datum_from_expr(PartitionPruneContext *context,
Expr *expr, int stateidx,
Datum *value, bool *isnull);
/*
* make_partition_pruneinfo
* Build List of PartitionPruneInfos, one for each partitioned rel.
* These can be used in the executor to allow additional partition
* pruning to take place.
*
* Here we generate partition pruning steps for 'prunequal' and also build a
* data structure which allows mapping of partition indexes into 'subpaths'
* indexes.
*
* If no non-Const expressions are being compared to the partition key in any
* of the 'partitioned_rels', then we return NIL to indicate no run-time
* pruning should be performed. Run-time pruning would be useless, since the
* pruning done during planning will have pruned everything that can be.
*/
List *
make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
List *subpaths, List *prunequal)
{
RelOptInfo *targetpart = NULL;
List *pinfolist = NIL;
bool doruntimeprune = false;
int *relid_subplan_map;
int *relid_subpart_map;
ListCell *lc;
int i;
/*
* Construct two temporary arrays to map from planner relids to subplan
* and sub-partition indexes. For convenience, we use 1-based indexes
* here, so that zero can represent an un-filled array entry.
*/
relid_subplan_map = palloc0(sizeof(int) * root->simple_rel_array_size);
relid_subpart_map = palloc0(sizeof(int) * root->simple_rel_array_size);
/*
* relid_subplan_map maps relid of a leaf partition to the index in
* 'subpaths' of the scan plan for that partition.
*/
i = 1;
foreach(lc, subpaths)
{
Path *path = (Path *) lfirst(lc);
RelOptInfo *pathrel = path->parent;
Assert(IS_SIMPLE_REL(pathrel));
Assert(pathrel->relid < root->simple_rel_array_size);
/* No duplicates please */
Assert(relid_subplan_map[pathrel->relid] == 0);
relid_subplan_map[pathrel->relid] = i++;
}
/*
* relid_subpart_map maps relid of a non-leaf partition to the index in
* 'partitioned_rels' of that rel (which will also be the index in the
* returned PartitionPruneInfo list of the info for that partition).
*/
i = 1;
foreach(lc, partitioned_rels)
{
Index rti = lfirst_int(lc);
Assert(rti < root->simple_rel_array_size);
/* No duplicates please */
Assert(relid_subpart_map[rti] == 0);
/* Same rel cannot be both leaf and non-leaf */
Assert(relid_subplan_map[rti] == 0);
relid_subpart_map[rti] = i++;
}
/* We now build a PartitionPruneInfo for each partitioned rel */
foreach(lc, partitioned_rels)
{
Index rti = lfirst_int(lc);
RelOptInfo *subpart = find_base_rel(root, rti);
PartitionPruneInfo *pinfo;
RangeTblEntry *rte;
Bitmapset *present_parts;
int nparts = subpart->nparts;
int partnatts = subpart->part_scheme->partnatts;
int *subplan_map;
int *subpart_map;
List *partprunequal;
List *pruning_steps;
bool contradictory;
/*
* The first item in the list is the target partitioned relation. The
* quals belong to this relation, so require no translation.
*/
if (!targetpart)
{
targetpart = subpart;
partprunequal = prunequal;
}
else
{
/*
* For sub-partitioned tables the columns may not be in the same
* order as the parent, so we must translate the prunequal to make
* it compatible with this relation.
*/
partprunequal = (List *)
adjust_appendrel_attrs_multilevel(root,
(Node *) prunequal,
subpart->relids,
targetpart->relids);
}
pruning_steps = gen_partprune_steps(subpart, partprunequal,
&contradictory);
if (contradictory)
{
/*
* This shouldn't happen as the planner should have detected this
* earlier. However, we do use additional quals from parameterized
* paths here. These do only compare Params to the partition key,
* so this shouldn't cause the discovery of any new qual
* contradictions that were not previously discovered as the Param
* values are unknown during planning. Anyway, we'd better do
* something sane here, so let's just disable run-time pruning.
*/
return NIL;
}
/*
* Construct the subplan and subpart maps for this partitioning level.
* Here we convert to zero-based indexes, with -1 for empty entries.
* Also construct a Bitmapset of all partitions that are present (that
* is, not pruned already).
*/
subplan_map = (int *) palloc(nparts * sizeof(int));
subpart_map = (int *) palloc(nparts * sizeof(int));
present_parts = NULL;
for (i = 0; i < nparts; i++)
{
RelOptInfo *partrel = subpart->part_rels[i];
int subplanidx = relid_subplan_map[partrel->relid] - 1;
int subpartidx = relid_subpart_map[partrel->relid] - 1;
subplan_map[i] = subplanidx;
subpart_map[i] = subpartidx;
if (subplanidx >= 0 || subpartidx >= 0)
present_parts = bms_add_member(present_parts, i);
}
rte = root->simple_rte_array[subpart->relid];
pinfo = makeNode(PartitionPruneInfo);
pinfo->reloid = rte->relid;
pinfo->pruning_steps = pruning_steps;
pinfo->present_parts = present_parts;
pinfo->nparts = nparts;
pinfo->subplan_map = subplan_map;
pinfo->subpart_map = subpart_map;
/* Determine which pruning types should be enabled at this level */
doruntimeprune |= analyze_partkey_exprs(pinfo, pruning_steps,
partnatts);
pinfolist = lappend(pinfolist, pinfo);
}
pfree(relid_subplan_map);
pfree(relid_subpart_map);
if (doruntimeprune)
return pinfolist;
/* No run-time pruning required. */
return NIL;
}
/*
* gen_partprune_steps
* Process 'clauses' (a rel's baserestrictinfo list of clauses) and return
* a list of "partition pruning steps"
*
* If the clauses in the input list are contradictory or there is a
* pseudo-constant "false", *contradictory is set to true upon return.
*/
static List *
gen_partprune_steps(RelOptInfo *rel, List *clauses, bool *contradictory)
{
GeneratePruningStepsContext context;
context.next_step_id = 0;
context.steps = NIL;
/* The clauses list may be modified below, so better make a copy. */
clauses = list_copy(clauses);
/*
* For sub-partitioned tables there's a corner case where if the
* sub-partitioned table shares any partition keys with its parent, then
* it's possible that the partitioning hierarchy allows the parent
* partition to only contain a narrower range of values than the
* sub-partitioned table does. In this case it is possible that we'd
* include partitions that could not possibly have any tuples matching
* 'clauses'. The possibility of such a partition arrangement is perhaps
* unlikely for non-default partitions, but it may be more likely in the
* case of default partitions, so we'll add the parent partition table's
* partition qual to the clause list in this case only. This may result
* in the default partition being eliminated.
*/
if (partition_bound_has_default(rel->boundinfo) &&
rel->partition_qual != NIL)
{
List *partqual = rel->partition_qual;
partqual = (List *) expression_planner((Expr *) partqual);
/* Fix Vars to have the desired varno */
if (rel->relid != 1)
ChangeVarNodes((Node *) partqual, 1, rel->relid, 0);
clauses = list_concat(clauses, partqual);
}
/* Down into the rabbit-hole. */
gen_partprune_steps_internal(&context, rel, clauses, contradictory);
return context.steps;
}
/*
* prune_append_rel_partitions
* Returns RT indexes of the minimum set of child partitions which must
* be scanned to satisfy rel's baserestrictinfo quals.
*
* Callers must ensure that 'rel' is a partitioned table.
*/
Relids
prune_append_rel_partitions(RelOptInfo *rel)
{
Relids result;
List *clauses = rel->baserestrictinfo;
List *pruning_steps;
bool contradictory;
PartitionPruneContext context;
Bitmapset *partindexes;
int i;
Assert(clauses != NIL);
Assert(rel->part_scheme != NULL);
/* If there are no partitions, return the empty set */
if (rel->nparts == 0)
return NULL;
/*
* Process clauses. If the clauses are found to be contradictory, we can
* return the empty set.
*/
pruning_steps = gen_partprune_steps(rel, clauses, &contradictory);
if (contradictory)
return NULL;
/* Set up PartitionPruneContext */
context.strategy = rel->part_scheme->strategy;
context.partnatts = rel->part_scheme->partnatts;
context.nparts = rel->nparts;
context.boundinfo = rel->boundinfo;
context.partcollation = rel->part_scheme->partcollation;
context.partsupfunc = rel->part_scheme->partsupfunc;
context.stepcmpfuncs = (FmgrInfo *) palloc0(sizeof(FmgrInfo) *
context.partnatts *
list_length(pruning_steps));
context.ppccontext = CurrentMemoryContext;
/* These are not valid when being called from the planner */
context.partrel = NULL;
context.planstate = NULL;
context.exprstates = NULL;
context.exprhasexecparam = NULL;
context.evalexecparams = false;
/* Actual pruning happens here. */
partindexes = get_matching_partitions(&context, pruning_steps);
/* Add selected partitions' RT indexes to result. */
i = -1;
result = NULL;
while ((i = bms_next_member(partindexes, i)) >= 0)
result = bms_add_member(result, rel->part_rels[i]->relid);
return result;
}
/*
* get_matching_partitions
* Determine partitions that survive partition pruning
*
* Returns a Bitmapset of the RelOptInfo->part_rels indexes of the surviving
* partitions.
*/
Bitmapset *
get_matching_partitions(PartitionPruneContext *context, List *pruning_steps)
{
Bitmapset *result;
int num_steps = list_length(pruning_steps),
i;
PruneStepResult **results,
*final_result;
ListCell *lc;
/* If there are no pruning steps then all partitions match. */
if (num_steps == 0)
return bms_add_range(NULL, 0, context->nparts - 1);
/*
* Allocate space for individual pruning steps to store its result. Each
* slot will hold a PruneStepResult after performing a given pruning step.
* Later steps may use the result of one or more earlier steps. The
* result of applying all pruning steps is the value contained in the slot
* of the last pruning step.
*/
results = (PruneStepResult **)
palloc0(num_steps * sizeof(PruneStepResult *));
foreach(lc, pruning_steps)
{
PartitionPruneStep *step = lfirst(lc);
switch (nodeTag(step))
{
case T_PartitionPruneStepOp:
results[step->step_id] =
perform_pruning_base_step(context,
(PartitionPruneStepOp *) step);
break;
case T_PartitionPruneStepCombine:
results[step->step_id] =
perform_pruning_combine_step(context,
(PartitionPruneStepCombine *) step,
results);
break;
default:
elog(ERROR, "invalid pruning step type: %d",
(int) nodeTag(step));
}
}
/*
* At this point we know the offsets of all the datums whose corresponding
* partitions need to be in the result, including special null-accepting
* and default partitions. Collect the actual partition indexes now.
*/
final_result = results[num_steps - 1];
Assert(final_result != NULL);
i = -1;
result = NULL;
while ((i = bms_next_member(final_result->bound_offsets, i)) >= 0)
{
int partindex = context->boundinfo->indexes[i];
/*
* In range and hash partitioning cases, some slots may contain -1,
* indicating that no partition has been defined to accept a given
* range of data or for a given remainder, respectively. The default
* partition, if any, in case of range partitioning, will be added to
* the result, because the specified range still satisfies the query's
* conditions.
*/
if (partindex >= 0)
result = bms_add_member(result, partindex);
}
/* Add the null and/or default partition if needed and if present. */
if (final_result->scan_null)
{
Assert(context->strategy == PARTITION_STRATEGY_LIST);
Assert(partition_bound_accepts_nulls(context->boundinfo));
result = bms_add_member(result, context->boundinfo->null_index);
}
if (final_result->scan_default)
{
Assert(context->strategy == PARTITION_STRATEGY_LIST ||
context->strategy == PARTITION_STRATEGY_RANGE);
Assert(partition_bound_has_default(context->boundinfo));
result = bms_add_member(result, context->boundinfo->default_index);
}
return result;
}
/*
* gen_partprune_steps_internal
* Processes 'clauses' to generate partition pruning steps.
*
* From OpExpr clauses that are mutually AND'd, we find combinations of those
* that match to the partition key columns and for every such combination,
* we emit a PartitionPruneStepOp containing a vector of expressions whose
* values are used as a look up key to search partitions by comparing the
* values with partition bounds. Relevant details of the operator and a
* vector of (possibly cross-type) comparison functions is also included with
* each step.
*
* For BoolExpr clauses, we recursively generate steps for each argument, and
* return a PartitionPruneStepCombine of their results.
*
* The return value is a list of the steps generated, which are also added to
* the context's steps list. Each step is assigned a step identifier, unique
* even across recursive calls.
*
* If we find clauses that are mutually contradictory, or a pseudoconstant
* clause that contains false, we set *contradictory to true and return NIL
* (that is, no pruning steps). Caller should consider all partitions as
* pruned in that case. Otherwise, *contradictory is set to false.
*
* Note: the 'clauses' List may be modified inside this function. Callers may
* like to make a copy of it before passing them to this function.
*/
static List *
gen_partprune_steps_internal(GeneratePruningStepsContext *context,
RelOptInfo *rel, List *clauses,
bool *contradictory)
{
PartitionScheme part_scheme = rel->part_scheme;
List *keyclauses[PARTITION_MAX_KEYS];
Bitmapset *nullkeys = NULL,
*notnullkeys = NULL;
bool generate_opsteps = false;
List *result = NIL;
ListCell *lc;
*contradictory = false;
memset(keyclauses, 0, sizeof(keyclauses));
foreach(lc, clauses)
{
Expr *clause = (Expr *) lfirst(lc);
int i;
/* Look through RestrictInfo, if any */
if (IsA(clause, RestrictInfo))
clause = ((RestrictInfo *) clause)->clause;
/* Constant-false-or-null is contradictory */
if (IsA(clause, Const) &&
(((Const *) clause)->constisnull ||
!DatumGetBool(((Const *) clause)->constvalue)))
{
*contradictory = true;
return NIL;
}
/* Get the BoolExpr's out of the way. */
if (IsA(clause, BoolExpr))
{
/*
* Generate steps for arguments.
*
* While steps generated for the arguments themselves will be
* added to context->steps during recursion and will be evaluated
* independently, collect their step IDs to be stored in the
* combine step we'll be creating.
*/
if (or_clause((Node *) clause))
{
List *arg_stepids = NIL;
bool all_args_contradictory = true;
ListCell *lc1;
/*
* Get pruning step for each arg. If we get contradictory for
* all args, it means the OR expression is false as a whole.
*/
foreach(lc1, ((BoolExpr *) clause)->args)
{
Expr *arg = lfirst(lc1);
bool arg_contradictory;
List *argsteps;
argsteps =
gen_partprune_steps_internal(context, rel,
list_make1(arg),
&arg_contradictory);
if (!arg_contradictory)
all_args_contradictory = false;
if (argsteps != NIL)
{
PartitionPruneStep *step;
Assert(list_length(argsteps) == 1);
step = (PartitionPruneStep *) linitial(argsteps);
arg_stepids = lappend_int(arg_stepids, step->step_id);
}
else
{
/*
* No steps either means that arg_contradictory is
* true or the arg didn't contain a clause matching
* this partition key.
*
* In case of the latter, we cannot prune using such
* an arg. To indicate that to the pruning code, we
* must construct a dummy PartitionPruneStepCombine
* whose source_stepids is set to an empty List.
* However, if we can prove using constraint exclusion
* that the clause refutes the table's partition
* constraint (if it's sub-partitioned), we need not
* bother with that. That is, we effectively ignore
* this OR arm.
*/
List *partconstr = rel->partition_qual;
PartitionPruneStep *orstep;
/* Just ignore this argument. */
if (arg_contradictory)
continue;
if (partconstr)
{
partconstr = (List *)
expression_planner((Expr *) partconstr);
if (rel->relid != 1)
ChangeVarNodes((Node *) partconstr, 1,
rel->relid, 0);
if (predicate_refuted_by(partconstr,
list_make1(arg),
false))
continue;
}
orstep = gen_prune_step_combine(context, NIL,
PARTPRUNE_COMBINE_UNION);
arg_stepids = lappend_int(arg_stepids, orstep->step_id);
}
}
*contradictory = all_args_contradictory;
/* Check if any contradicting clauses were found */
if (*contradictory)
return NIL;
if (arg_stepids != NIL)
{
PartitionPruneStep *step;
step = gen_prune_step_combine(context, arg_stepids,
PARTPRUNE_COMBINE_UNION);
result = lappend(result, step);
}
continue;
}
else if (and_clause((Node *) clause))
{
List *args = ((BoolExpr *) clause)->args;
List *argsteps,
*arg_stepids = NIL;
ListCell *lc1;
/*
* args may itself contain clauses of arbitrary type, so just
* recurse and later combine the component partitions sets
* using a combine step.
*/
argsteps = gen_partprune_steps_internal(context, rel, args,
contradictory);
if (*contradictory)
return NIL;
foreach(lc1, argsteps)
{
PartitionPruneStep *step = lfirst(lc1);
arg_stepids = lappend_int(arg_stepids, step->step_id);
}
if (arg_stepids != NIL)
{
PartitionPruneStep *step;
step = gen_prune_step_combine(context, arg_stepids,
PARTPRUNE_COMBINE_INTERSECT);
result = lappend(result, step);
}
continue;
}
/*
* Fall-through for a NOT clause, which if it's a Boolean clause,
* will be handled in match_clause_to_partition_key(). We
* currently don't perform any pruning for more complex NOT
* clauses.
*/
}
/*
* Must be a clause for which we can check if one of its args matches
* the partition key.
*/
for (i = 0; i < part_scheme->partnatts; i++)
{
Expr *partkey = linitial(rel->partexprs[i]);
bool clause_is_not_null = false;
PartClauseInfo *pc = NULL;
List *clause_steps = NIL;
switch (match_clause_to_partition_key(rel, context,
clause, partkey, i,
&clause_is_not_null,
&pc, &clause_steps))
{
case PARTCLAUSE_MATCH_CLAUSE:
Assert(pc != NULL);
/*
* Since we only allow strict operators, check for any
* contradicting IS NULL.
*/
if (bms_is_member(i, nullkeys))
{
*contradictory = true;
return NIL;
}
generate_opsteps = true;
keyclauses[i] = lappend(keyclauses[i], pc);
break;
case PARTCLAUSE_MATCH_NULLNESS:
if (!clause_is_not_null)
{
/* check for conflicting IS NOT NULL */
if (bms_is_member(i, notnullkeys))
{
*contradictory = true;
return NIL;
}
nullkeys = bms_add_member(nullkeys, i);
}
else
{
/* check for conflicting IS NULL */
if (bms_is_member(i, nullkeys))
{
*contradictory = true;
return NIL;
}
notnullkeys = bms_add_member(notnullkeys, i);
}
break;
case PARTCLAUSE_MATCH_STEPS:
Assert(clause_steps != NIL);
result = list_concat(result, clause_steps);
break;
case PARTCLAUSE_MATCH_CONTRADICT:
/* We've nothing more to do if a contradiction was found. */
*contradictory = true;
return NIL;
case PARTCLAUSE_NOMATCH:
/*
* Clause didn't match this key, but it might match the
* next one.
*/
continue;
case PARTCLAUSE_UNSUPPORTED:
/* This clause cannot be used for pruning. */
break;
}
/* done; go check the next clause. */
break;
}
}
/*
* If generate_opsteps is set to false it means no OpExprs were directly
* present in the input list.
*/
if (!generate_opsteps)
{
/*
* Generate one prune step for the information derived from IS NULL,
* if any. To prune hash partitions, we must have found IS NULL
* clauses for all partition keys.
*/
if (!bms_is_empty(nullkeys) &&
(part_scheme->strategy != PARTITION_STRATEGY_HASH ||
bms_num_members(nullkeys) == part_scheme->partnatts))
{
PartitionPruneStep *step;
step = gen_prune_step_op(context, InvalidStrategy,
false, NIL, NIL, nullkeys);
result = lappend(result, step);
}
/*
* Note that for IS NOT NULL clauses, simply having step suffices;
* there is no need to propagate the exact details of which keys are
* required to be NOT NULL. Hash partitioning expects to see actual
* values to perform any pruning.
*/
if (!bms_is_empty(notnullkeys) &&
part_scheme->strategy != PARTITION_STRATEGY_HASH)
{
PartitionPruneStep *step;
step = gen_prune_step_op(context, InvalidStrategy,
false, NIL, NIL, NULL);
result = lappend(result, step);
}
}
else
{
PartitionPruneStep *step;
/* Generate pruning steps from OpExpr clauses in keyclauses. */
step = gen_prune_steps_from_opexps(part_scheme, context,
keyclauses, nullkeys);
if (step != NULL)
result = lappend(result, step);
}
/*
* Finally, results from all entries appearing in result should be
* combined using an INTERSECT combine step, if more than one.
*/
if (list_length(result) > 1)
{
List *step_ids = NIL;
foreach(lc, result)
{
PartitionPruneStep *step = lfirst(lc);
step_ids = lappend_int(step_ids, step->step_id);
}
if (step_ids != NIL)
{
PartitionPruneStep *step;
step = gen_prune_step_combine(context, step_ids,
PARTPRUNE_COMBINE_INTERSECT);
result = lappend(result, step);
}
}
return result;
}
/*
* gen_prune_step_op
* Generate a pruning step for a specific operator
*
* The step is assigned a unique step identifier and added to context's 'steps'
* list.
*/
static PartitionPruneStep *
gen_prune_step_op(GeneratePruningStepsContext *context,
StrategyNumber opstrategy, bool op_is_ne,
List *exprs, List *cmpfns,
Bitmapset *nullkeys)
{
PartitionPruneStepOp *opstep = makeNode(PartitionPruneStepOp);
opstep->step.step_id = context->next_step_id++;
/*
* For clauses that contain an <> operator, set opstrategy to
* InvalidStrategy to signal get_matching_list_bounds to do the right
* thing.
*/
opstep->opstrategy = op_is_ne ? InvalidStrategy : opstrategy;
Assert(list_length(exprs) == list_length(cmpfns));
opstep->exprs = exprs;
opstep->cmpfns = cmpfns;
opstep->nullkeys = nullkeys;
context->steps = lappend(context->steps, opstep);
return (PartitionPruneStep *) opstep;
}
/*
* gen_prune_step_combine
* Generate a pruning step for a combination of several other steps
*
* The step is assigned a unique step identifier and added to context's
* 'steps' list.
*/
static PartitionPruneStep *
gen_prune_step_combine(GeneratePruningStepsContext *context,
List *source_stepids,
PartitionPruneCombineOp combineOp)
{
PartitionPruneStepCombine *cstep = makeNode(PartitionPruneStepCombine);
cstep->step.step_id = context->next_step_id++;
cstep->combineOp = combineOp;
cstep->source_stepids = source_stepids;
context->steps = lappend(context->steps, cstep);
return (PartitionPruneStep *) cstep;
}
/*
* gen_prune_steps_from_opexps
* Generate pruning steps based on clauses for partition keys
*
* 'keyclauses' contains one list of clauses per partition key. We check here
* if we have found clauses for a valid subset of the partition key. In some
* cases, (depending on the type of partitioning being used) if we didn't
* find clauses for a given key, we discard clauses that may have been
* found for any subsequent keys; see specific notes below.
*/
static PartitionPruneStep *
gen_prune_steps_from_opexps(PartitionScheme part_scheme,
GeneratePruningStepsContext *context,
List **keyclauses, Bitmapset *nullkeys)
{
ListCell *lc;
List *opsteps = NIL;
List *btree_clauses[BTMaxStrategyNumber + 1],
*hash_clauses[HTMaxStrategyNumber + 1];
bool need_next_less,
need_next_eq,
need_next_greater;
int i;
memset(btree_clauses, 0, sizeof(btree_clauses));
memset(hash_clauses, 0, sizeof(hash_clauses));
for (i = 0; i < part_scheme->partnatts; i++)
{
List *clauselist = keyclauses[i];
bool consider_next_key = true;
/*
* To be useful for pruning, we must have clauses for a prefix of
* partition keys in the case of range partitioning. So, ignore
* clauses for keys after this one.
*/
if (part_scheme->strategy == PARTITION_STRATEGY_RANGE &&
clauselist == NIL)
break;
/*
* For hash partitioning, if a column doesn't have the necessary
* equality clause, there should be an IS NULL clause, otherwise
* pruning is not possible.
*/
if (part_scheme->strategy == PARTITION_STRATEGY_HASH &&
clauselist == NIL && !bms_is_member(i, nullkeys))
return NULL;
need_next_eq = need_next_less = need_next_greater = true;
foreach(lc, clauselist)
{
PartClauseInfo *pc = (PartClauseInfo *) lfirst(lc);
Oid lefttype,
righttype;
/* Look up the operator's btree/hash strategy number. */
if (pc->op_strategy == InvalidStrategy)
get_op_opfamily_properties(pc->opno,
part_scheme->partopfamily[i],
false,
&pc->op_strategy,
&lefttype,
&righttype);
switch (part_scheme->strategy)
{
case PARTITION_STRATEGY_LIST:
case PARTITION_STRATEGY_RANGE:
{
PartClauseInfo *last = NULL;
bool inclusive = false;
/*
* Add this clause to the list of clauses to be used
* for pruning if this is the first such key for this
* operator strategy or if it is consecutively next to
* the last column for which a clause with this
* operator strategy was matched.
*/
if (btree_clauses[pc->op_strategy] != NIL)
last = llast(btree_clauses[pc->op_strategy]);
if (last == NULL ||
i == last->keyno || i == last->keyno + 1)
btree_clauses[pc->op_strategy] =
lappend(btree_clauses[pc->op_strategy], pc);
/*
* We may not need the next clause if they're of
* certain strategy.
*/
switch (pc->op_strategy)
{
case BTLessEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTLessStrategyNumber:
if (!inclusive)
need_next_eq = need_next_less = false;
break;
case BTEqualStrategyNumber:
/* always accept clauses for the next key. */
break;
case BTGreaterEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTGreaterStrategyNumber:
if (!inclusive)
need_next_eq = need_next_greater = false;
break;
}
/* We may want to change our mind. */
if (consider_next_key)
consider_next_key = (need_next_eq ||
need_next_less ||
need_next_greater);
break;
}
case PARTITION_STRATEGY_HASH:
if (pc->op_strategy != HTEqualStrategyNumber)
elog(ERROR, "invalid clause for hash partitioning");
hash_clauses[pc->op_strategy] =
lappend(hash_clauses[pc->op_strategy], pc);
break;
default:
elog(ERROR, "invalid partition strategy: %c",
part_scheme->strategy);
break;
}
}
/*
* If we've decided that clauses for subsequent partition keys
* wouldn't be useful for pruning, don't search any further.
*/
if (!consider_next_key)
break;
}
/*
* Now, we have divided clauses according to their operator strategies.
* Check for each strategy if we can generate pruning step(s) by
* collecting a list of expressions whose values will constitute a vector
* that can be used as a lookup key by a partition bound searching
* function.
*/
switch (part_scheme->strategy)
{
case PARTITION_STRATEGY_LIST:
case PARTITION_STRATEGY_RANGE:
{
List *eq_clauses = btree_clauses[BTEqualStrategyNumber];
List *le_clauses = btree_clauses[BTLessEqualStrategyNumber];
List *ge_clauses = btree_clauses[BTGreaterEqualStrategyNumber];
int strat;
/*
* For each clause under consideration for a given strategy,
* we collect expressions from clauses for earlier keys, whose
* operator strategy is inclusive, into a list called
* 'prefix'. By appending the clause's own expression to the
* 'prefix', we'll generate one step using the so generated
* vector and assign the current strategy to it. Actually,
* 'prefix' might contain multiple clauses for the same key,
* in which case, we must generate steps for various
* combinations of expressions of different keys, which
* get_steps_using_prefix takes care of for us.
*/
for (strat = 1; strat <= BTMaxStrategyNumber; strat++)
{
foreach(lc, btree_clauses[strat])
{
PartClauseInfo *pc = lfirst(lc);
ListCell *lc1;
List *prefix = NIL;
List *pc_steps;
/*
* Expressions from = clauses can always be in the
* prefix, provided they're from an earlier key.
*/
foreach(lc1, eq_clauses)
{
PartClauseInfo *eqpc = lfirst(lc1);
if (eqpc->keyno == pc->keyno)
break;
if (eqpc->keyno < pc->keyno)
prefix = lappend(prefix, eqpc);
}
/*
* If we're generating steps for </<= strategy, we can
* add other <= clauses to the prefix, provided
* they're from an earlier key.
*/
if (strat == BTLessStrategyNumber ||
strat == BTLessEqualStrategyNumber)
{
foreach(lc1, le_clauses)
{
PartClauseInfo *lepc = lfirst(lc1);
if (lepc->keyno == pc->keyno)
break;
if (lepc->keyno < pc->keyno)
prefix = lappend(prefix, lepc);
}
}
/*
* If we're generating steps for >/>= strategy, we can
* add other >= clauses to the prefix, provided
* they're from an earlier key.
*/
if (strat == BTGreaterStrategyNumber ||
strat == BTGreaterEqualStrategyNumber)
{
foreach(lc1, ge_clauses)
{
PartClauseInfo *gepc = lfirst(lc1);
if (gepc->keyno == pc->keyno)
break;
if (gepc->keyno < pc->keyno)
prefix = lappend(prefix, gepc);
}
}
/*
* As mentioned above, if 'prefix' contains multiple
* expressions for the same key, the following will
* generate multiple steps, one for each combination
* of the expressions for different keys.
*
* Note that we pass NULL for step_nullkeys, because
* we don't search list/range partition bounds where
* some keys are NULL.
*/
Assert(pc->op_strategy == strat);
pc_steps = get_steps_using_prefix(context, strat,
pc->op_is_ne,
pc->expr,
pc->cmpfn,
pc->keyno,
NULL,
prefix);
opsteps = list_concat(opsteps, list_copy(pc_steps));
}
}
break;
}
case PARTITION_STRATEGY_HASH:
{
List *eq_clauses = hash_clauses[HTEqualStrategyNumber];
/* For hash partitioning, we have just the = strategy. */
if (eq_clauses != NIL)
{
PartClauseInfo *pc;
List *pc_steps;
List *prefix = NIL;
int last_keyno;
ListCell *lc1;
/*
* Locate the clause for the greatest column. This may
* not belong to the last partition key, but it is the
* clause belonging to the last partition key we found a
* clause for above.
*/
pc = llast(eq_clauses);
/*
* There might be multiple clauses which matched to that
* partition key; find the first such clause. While at
* it, add all the clauses before that one to 'prefix'.
*/
last_keyno = pc->keyno;
foreach(lc, eq_clauses)
{
pc = lfirst(lc);
if (pc->keyno == last_keyno)
break;
prefix = lappend(prefix, pc);
}
/*
* For each clause for the "last" column, after appending
* the clause's own expression to the 'prefix', we'll
* generate one step using the so generated vector and and
* assign = as its strategy. Actually, 'prefix' might
* contain multiple clauses for the same key, in which
* case, we must generate steps for various combinations
* of expressions of different keys, which
* get_steps_using_prefix will take care of for us.
*/
for_each_cell(lc1, lc)
{
pc = lfirst(lc1);
/*
* Note that we pass nullkeys for step_nullkeys,
* because we need to tell hash partition bound search
* function which of the keys we found IS NULL clauses
* for.
*/
Assert(pc->op_strategy == HTEqualStrategyNumber);
pc_steps =
get_steps_using_prefix(context,
HTEqualStrategyNumber,
false,
pc->expr,
pc->cmpfn,
pc->keyno,
nullkeys,
prefix);
opsteps = list_concat(opsteps, list_copy(pc_steps));
}
}
break;
}
default:
elog(ERROR, "invalid partition strategy: %c",
part_scheme->strategy);
break;
}
/* Lastly, add a combine step to mutually AND these op steps, if needed */
if (list_length(opsteps) > 1)
{
List *opstep_ids = NIL;
foreach(lc, opsteps)
{
PartitionPruneStep *step = lfirst(lc);
opstep_ids = lappend_int(opstep_ids, step->step_id);
}
if (opstep_ids != NIL)
return gen_prune_step_combine(context, opstep_ids,
PARTPRUNE_COMBINE_INTERSECT);
return NULL;
}
else if (opsteps != NIL)
return linitial(opsteps);
return NULL;
}
/*
* If the partition key has a collation, then the clause must have the same
* input collation. If the partition key is non-collatable, we assume the
* collation doesn't matter, because while collation wasn't considered when
* performing partitioning, the clause still may have a collation assigned
* due to the other input being of a collatable type.
*
* See also IndexCollMatchesExprColl.
*/
#define PartCollMatchesExprColl(partcoll, exprcoll) \
((partcoll) == InvalidOid || (partcoll) == (exprcoll))
/*
* match_clause_to_partition_key
* Attempt to match the given 'clause' with the specified partition key.
*
* Return value is:
* * PARTCLAUSE_NOMATCH if the clause doesn't match this partition key (but
* caller should keep trying, because it might match a subsequent key).
* Output arguments: none set.
*
* * PARTCLAUSE_MATCH_CLAUSE if there is a match.
* Output arguments: *pc is set to a PartClauseInfo constructed for the
* matched clause.
*
* * PARTCLAUSE_MATCH_NULLNESS if there is a match, and the matched clause was
* either a "a IS NULL" or "a IS NOT NULL" clause.
* Output arguments: *clause_is_not_null is set to false in the former case
* true otherwise.
*
* * PARTCLAUSE_MATCH_STEPS if there is a match.
* Output arguments: *clause_steps is set to a list of PartitionPruneStep
* generated for the clause.
*
* * PARTCLAUSE_MATCH_CONTRADICT if the clause is self-contradictory, ie
* it provably returns FALSE or NULL.
* Output arguments: none set.
*
* * PARTCLAUSE_UNSUPPORTED if the clause doesn't match this partition key
* and couldn't possibly match any other one either, due to its form or
* properties (such as containing a volatile function).
* Output arguments: none set.
*/
static PartClauseMatchStatus
match_clause_to_partition_key(RelOptInfo *rel,
GeneratePruningStepsContext *context,
Expr *clause, Expr *partkey, int partkeyidx,
bool *clause_is_not_null, PartClauseInfo **pc,
List **clause_steps)
{
PartitionScheme part_scheme = rel->part_scheme;
Oid partopfamily = part_scheme->partopfamily[partkeyidx],
partcoll = part_scheme->partcollation[partkeyidx];
Expr *expr;
/*
* Recognize specially shaped clauses that match with the Boolean
* partition key.
*/
if (match_boolean_partition_clause(partopfamily, clause, partkey, &expr))
{
PartClauseInfo *partclause;
partclause = (PartClauseInfo *) palloc(sizeof(PartClauseInfo));
partclause->keyno = partkeyidx;
/* Do pruning with the Boolean equality operator. */
partclause->opno = BooleanEqualOperator;
partclause->op_is_ne = false;
partclause->expr = expr;
/* We know that expr is of Boolean type. */
partclause->cmpfn = rel->part_scheme->partsupfunc[partkeyidx].fn_oid;
partclause->op_strategy = InvalidStrategy;
*pc = partclause;
return PARTCLAUSE_MATCH_CLAUSE;
}
else if (IsA(clause, OpExpr) &&
list_length(((OpExpr *) clause)->args) == 2)
{
OpExpr *opclause = (OpExpr *) clause;
Expr *leftop,
*rightop;
Oid opno,
op_lefttype,
op_righttype,
negator = InvalidOid;
Oid cmpfn;
int op_strategy;
bool is_opne_listp = false;
PartClauseInfo *partclause;
leftop = (Expr *) get_leftop(clause);
if (IsA(leftop, RelabelType))
leftop = ((RelabelType *) leftop)->arg;
rightop = (Expr *) get_rightop(clause);
if (IsA(rightop, RelabelType))
rightop = ((RelabelType *) rightop)->arg;
opno = opclause->opno;
/* check if the clause matches this partition key */
if (equal(leftop, partkey))
expr = rightop;
else if (equal(rightop, partkey))
{
/*
* It's only useful if we can commute the operator to put the
* partkey on the left. If we can't, the clause can be deemed
* UNSUPPORTED. Even if its leftop matches some later partkey, we
* now know it has Vars on the right, so it's no use.
*/
opno = get_commutator(opno);
if (!OidIsValid(opno))
return PARTCLAUSE_UNSUPPORTED;
expr = leftop;
}
else
/* clause does not match this partition key, but perhaps next. */
return PARTCLAUSE_NOMATCH;
/*
* Partition key match also requires collation match. There may be
* multiple partkeys with the same expression but different
* collations, so failure is NOMATCH.
*/
if (!PartCollMatchesExprColl(partcoll, opclause->inputcollid))
return PARTCLAUSE_NOMATCH;
/*
* Matched with this key. Now check various properties of the clause
* to see if it's sane to use it for pruning. In most of these cases,
* we can return UNSUPPORTED because the same failure would occur no
* matter which partkey it's matched to.
*/
/*
* We can't prune using an expression with Vars. (Report failure as
* UNSUPPORTED, not NOMATCH: as in the no-commutator case above, we
* now know there are Vars on both sides, so it's no good.)
*/
if (contain_var_clause((Node *) expr))
return PARTCLAUSE_UNSUPPORTED;
/*
* Only allow strict operators. This will guarantee nulls are
* filtered.
*/
if (!op_strict(opno))
return PARTCLAUSE_UNSUPPORTED;
/* We can't use any volatile expressions to prune partitions. */
if (contain_volatile_functions((Node *) expr))
return PARTCLAUSE_UNSUPPORTED;
/*
* See if the operator is relevant to the partitioning opfamily.
*
* Normally we only care about operators that are listed as being part
* of the partitioning operator family. But there is one exception:
* the not-equals operators are not listed in any operator family
* whatsoever, but their negators (equality) are. We can use one of
* those if we find it, but only for list partitioning.
*
* Note: we report NOMATCH on failure, in case a later partkey has the
* same expression but different opfamily. That's unlikely, but not
* much more so than duplicate expressions with different collations.
*/
if (op_in_opfamily(opno, partopfamily))
{
get_op_opfamily_properties(opno, partopfamily, false,
&op_strategy, &op_lefttype,
&op_righttype);
}
else
{
if (part_scheme->strategy != PARTITION_STRATEGY_LIST)
return PARTCLAUSE_NOMATCH;
/* See if the negator is equality */
negator = get_negator(opno);
if (OidIsValid(negator) && op_in_opfamily(negator, partopfamily))
{
get_op_opfamily_properties(negator, partopfamily, false,
&op_strategy, &op_lefttype,
&op_righttype);
if (op_strategy == BTEqualStrategyNumber)
is_opne_listp = true; /* bingo */
}
/* Nope, it's not <> either. */
if (!is_opne_listp)
return PARTCLAUSE_NOMATCH;
}
/*
* Now find the procedure to use, based on the types. If the clause's
* other argument is of the same type as the partitioning opclass's
* declared input type, we can use the procedure cached in
* PartitionKey. If not, search for a cross-type one in the same
* opfamily; if one doesn't exist, report no match.
*/
if (op_righttype == part_scheme->partopcintype[partkeyidx])
cmpfn = part_scheme->partsupfunc[partkeyidx].fn_oid;
else
{
switch (part_scheme->strategy)
{
/*
* For range and list partitioning, we need the ordering
* procedure with lefttype being the partition key's type,
* and righttype the clause's operator's right type.
*/
case PARTITION_STRATEGY_LIST:
case PARTITION_STRATEGY_RANGE:
cmpfn =
get_opfamily_proc(part_scheme->partopfamily[partkeyidx],
part_scheme->partopcintype[partkeyidx],
op_righttype, BTORDER_PROC);
break;
/*
* For hash partitioning, we need the hashing procedure
* for the clause's type.
*/
case PARTITION_STRATEGY_HASH:
cmpfn =
get_opfamily_proc(part_scheme->partopfamily[partkeyidx],
op_righttype, op_righttype,
HASHEXTENDED_PROC);
break;
default:
elog(ERROR, "invalid partition strategy: %c",
part_scheme->strategy);
cmpfn = InvalidOid; /* keep compiler quiet */
break;
}
if (!OidIsValid(cmpfn))
return PARTCLAUSE_NOMATCH;
}
/*
* Build the clause, passing the negator if applicable.
*/
partclause = (PartClauseInfo *) palloc(sizeof(PartClauseInfo));
partclause->keyno = partkeyidx;
if (is_opne_listp)
{
Assert(OidIsValid(negator));
partclause->opno = negator;
partclause->op_is_ne = true;
partclause->op_strategy = InvalidStrategy;
}
else
{
partclause->opno = opno;
partclause->op_is_ne = false;
partclause->op_strategy = op_strategy;
}
partclause->expr = expr;
partclause->cmpfn = cmpfn;
*pc = partclause;
return PARTCLAUSE_MATCH_CLAUSE;
}
else if (IsA(clause, ScalarArrayOpExpr))
{
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
Oid saop_op = saop->opno;
Oid saop_coll = saop->inputcollid;
Expr *leftop = (Expr *) linitial(saop->args),
*rightop = (Expr *) lsecond(saop->args);
List *elem_exprs,
*elem_clauses;
ListCell *lc1;
bool contradictory;
if (IsA(leftop, RelabelType))
leftop = ((RelabelType *) leftop)->arg;
/* Check it matches this partition key */
if (!equal(leftop, partkey) ||
!PartCollMatchesExprColl(partcoll, saop->inputcollid))
return PARTCLAUSE_NOMATCH;
/*
* Matched with this key. Check various properties of the clause to
* see if it can sanely be used for partition pruning (this is mostly
* the same as for a plain OpExpr).
*/
/* We can't prune using an expression with Vars. */
if (contain_var_clause((Node *) rightop))
return PARTCLAUSE_UNSUPPORTED;
/*
* Only allow strict operators. This will guarantee nulls are
* filtered.
*/
if (!op_strict(saop_op))
return PARTCLAUSE_UNSUPPORTED;
/* We can't use any volatile expressions to prune partitions. */
if (contain_volatile_functions((Node *) rightop))
return PARTCLAUSE_UNSUPPORTED;
/*
* In case of NOT IN (..), we get a '<>', which we handle if list
* partitioning is in use and we're able to confirm that it's negator
* is a btree equality operator belonging to the partitioning operator
* family. As above, report NOMATCH for non-matching operator.
*/
if (!op_in_opfamily(saop_op, partopfamily))
{
Oid negator;
if (part_scheme->strategy != PARTITION_STRATEGY_LIST)
return PARTCLAUSE_NOMATCH;
negator = get_negator(saop_op);
if (OidIsValid(negator) && op_in_opfamily(negator, partopfamily))
{
int strategy;
Oid lefttype,
righttype;
get_op_opfamily_properties(negator, partopfamily,
false, &strategy,
&lefttype, &righttype);
if (strategy != BTEqualStrategyNumber)
return PARTCLAUSE_NOMATCH;
}
else
return PARTCLAUSE_NOMATCH; /* no useful negator */
}
/*
* First generate a list of Const nodes, one for each array element
* (excepting nulls).
*/
elem_exprs = NIL;
if (IsA(rightop, Const))
{
Const *arr = (Const *) rightop;
ArrayType *arrval = DatumGetArrayTypeP(arr->constvalue);
int16 elemlen;
bool elembyval;
char elemalign;
Datum *elem_values;
bool *elem_nulls;
int num_elems,
i;
get_typlenbyvalalign(ARR_ELEMTYPE(arrval),
&elemlen, &elembyval, &elemalign);
deconstruct_array(arrval,
ARR_ELEMTYPE(arrval),
elemlen, elembyval, elemalign,
&elem_values, &elem_nulls,
&num_elems);
for (i = 0; i < num_elems; i++)
{
Const *elem_expr;
/*
* A null array element must lead to a null comparison result,
* since saop_op is known strict. We can ignore it in the
* useOr case, but otherwise it implies self-contradiction.
*/
if (elem_nulls[i])
{
if (saop->useOr)
continue;
return PARTCLAUSE_MATCH_CONTRADICT;
}
elem_expr = makeConst(ARR_ELEMTYPE(arrval), -1,
arr->constcollid, elemlen,
elem_values[i], false, elembyval);
elem_exprs = lappend(elem_exprs, elem_expr);
}
}
else if (IsA(rightop, ArrayExpr))
{
ArrayExpr *arrexpr = castNode(ArrayExpr, rightop);
/*
* For a nested ArrayExpr, we don't know how to get the actual
* scalar values out into a flat list, so we give up doing
* anything with this ScalarArrayOpExpr.
*/
if (arrexpr->multidims)
return PARTCLAUSE_UNSUPPORTED;
elem_exprs = arrexpr->elements;
}
else
{
/* Give up on any other clause types. */
return PARTCLAUSE_UNSUPPORTED;
}
/*
* Now generate a list of clauses, one for each array element, of the
* form saop_leftop saop_op elem_expr
*/
elem_clauses = NIL;
foreach(lc1, elem_exprs)
{
Expr *rightop = (Expr *) lfirst(lc1),
*elem_clause;
elem_clause = make_opclause(saop_op, BOOLOID, false,
leftop, rightop,
InvalidOid, saop_coll);
elem_clauses = lappend(elem_clauses, elem_clause);
}
/*
* If we have an ANY clause and multiple elements, now turn the list
* of clauses into an OR expression.
*/
if (saop->useOr && list_length(elem_clauses) > 1)
elem_clauses = list_make1(makeBoolExpr(OR_EXPR, elem_clauses, -1));
/* Finally, generate steps */
*clause_steps =
gen_partprune_steps_internal(context, rel, elem_clauses,
&contradictory);
if (contradictory)
return PARTCLAUSE_MATCH_CONTRADICT;
else if (*clause_steps == NIL)
return PARTCLAUSE_UNSUPPORTED; /* step generation failed */
return PARTCLAUSE_MATCH_STEPS;
}
else if (IsA(clause, NullTest))
{
NullTest *nulltest = (NullTest *) clause;
Expr *arg = nulltest->arg;
if (IsA(arg, RelabelType))
arg = ((RelabelType *) arg)->arg;
/* Does arg match with this partition key column? */
if (!equal(arg, partkey))
return PARTCLAUSE_NOMATCH;
*clause_is_not_null = (nulltest->nulltesttype == IS_NOT_NULL);
return PARTCLAUSE_MATCH_NULLNESS;
}
return PARTCLAUSE_UNSUPPORTED;
}
/*
* get_steps_using_prefix
* Generate list of PartitionPruneStepOp steps each consisting of given
* opstrategy
*
* To generate steps, step_lastexpr and step_lastcmpfn are appended to
* expressions and cmpfns, respectively, extracted from the clauses in
* 'prefix'. Actually, since 'prefix' may contain multiple clauses for the
* same partition key column, we must generate steps for various combinations
* of the clauses of different keys.
*/
static List *
get_steps_using_prefix(GeneratePruningStepsContext *context,
StrategyNumber step_opstrategy,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix)
{
/* Quick exit if there are no values to prefix with. */
if (list_length(prefix) == 0)
{
PartitionPruneStep *step;
step = gen_prune_step_op(context,
step_opstrategy,
step_op_is_ne,
list_make1(step_lastexpr),
list_make1_oid(step_lastcmpfn),
step_nullkeys);
return list_make1(step);
}
/* Recurse to generate steps for various combinations. */
return get_steps_using_prefix_recurse(context,
step_opstrategy,
step_op_is_ne,
step_lastexpr,
step_lastcmpfn,
step_lastkeyno,
step_nullkeys,
list_head(prefix),
NIL, NIL);
}
/*
* get_steps_using_prefix_recurse
* Recursively generate combinations of clauses for different partition
* keys and start generating steps upon reaching clauses for the greatest
* column that is less than the one for which we're currently generating
* steps (that is, step_lastkeyno)
*
* 'start' is where we should start iterating for the current invocation.
* 'step_exprs' and 'step_cmpfns' each contains the expressions and cmpfns
* we've generated so far from the clauses for the previous part keys.
*/
static List *
get_steps_using_prefix_recurse(GeneratePruningStepsContext *context,
StrategyNumber step_opstrategy,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
int step_lastkeyno,
Bitmapset *step_nullkeys,
ListCell *start,
List *step_exprs,
List *step_cmpfns)
{
List *result = NIL;
ListCell *lc;
int cur_keyno;
/* Actually, recursion would be limited by PARTITION_MAX_KEYS. */
check_stack_depth();
/* Check if we need to recurse. */
Assert(start != NULL);
cur_keyno = ((PartClauseInfo *) lfirst(start))->keyno;
if (cur_keyno < step_lastkeyno - 1)
{
PartClauseInfo *pc;
ListCell *next_start;
/*
* For each clause with cur_keyno, adds its expr and cmpfn to
* step_exprs and step_cmpfns, respectively, and recurse after setting
* next_start to the ListCell of the first clause for the next
* partition key.
*/
for_each_cell(lc, start)
{
pc = lfirst(lc);
if (pc->keyno > cur_keyno)
break;
}
next_start = lc;
for_each_cell(lc, start)
{
List *moresteps;
pc = lfirst(lc);
if (pc->keyno == cur_keyno)
{
/* clean up before starting a new recursion cycle. */
if (cur_keyno == 0)
{
list_free(step_exprs);
list_free(step_cmpfns);
step_exprs = list_make1(pc->expr);
step_cmpfns = list_make1_oid(pc->cmpfn);
}
else
{
step_exprs = lappend(step_exprs, pc->expr);
step_cmpfns = lappend_oid(step_cmpfns, pc->cmpfn);
}
}
else
{
Assert(pc->keyno > cur_keyno);
break;
}
moresteps = get_steps_using_prefix_recurse(context,
step_opstrategy,
step_op_is_ne,
step_lastexpr,
step_lastcmpfn,
step_lastkeyno,
step_nullkeys,
next_start,
step_exprs,
step_cmpfns);
result = list_concat(result, moresteps);
}
}
else
{
/*
* End the current recursion cycle and start generating steps, one for
* each clause with cur_keyno, which is all clauses from here onward
* till the end of the list.
*/
Assert(list_length(step_exprs) == cur_keyno);
for_each_cell(lc, start)
{
PartClauseInfo *pc = lfirst(lc);
PartitionPruneStep *step;
List *step_exprs1,
*step_cmpfns1;
Assert(pc->keyno == cur_keyno);
/* Leave the original step_exprs unmodified. */
step_exprs1 = list_copy(step_exprs);
step_exprs1 = lappend(step_exprs1, pc->expr);
step_exprs1 = lappend(step_exprs1, step_lastexpr);
/* Leave the original step_cmpfns unmodified. */
step_cmpfns1 = list_copy(step_cmpfns);
step_cmpfns1 = lappend_oid(step_cmpfns1, pc->cmpfn);
step_cmpfns1 = lappend_oid(step_cmpfns1, step_lastcmpfn);
step = gen_prune_step_op(context,
step_opstrategy, step_op_is_ne,
step_exprs1, step_cmpfns1,
step_nullkeys);
result = lappend(result, step);
}
}
return result;
}
/*
* get_matching_hash_bounds
* Determine offset of the hash bound matching the specified values,
* considering that all the non-null values come from clauses containing
* a compatible hash equality operator and any keys that are null come
* from an IS NULL clause.
*
* Generally this function will return a single matching bound offset,
* although if a partition has not been setup for a given modulus then we may
* return no matches. If the number of clauses found don't cover the entire
* partition key, then we'll need to return all offsets.
*
* 'opstrategy' if non-zero must be HTEqualStrategyNumber.
*
* 'values' contains Datums indexed by the partition key to use for pruning.
*
* 'nvalues', the number of Datums in the 'values' array.
*
* 'partsupfunc' contains partition hashing functions that can produce correct
* hash for the type of the values contained in 'values'.
*
* 'nullkeys' is the set of partition keys that are null.
*/
static PruneStepResult *
get_matching_hash_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum *values, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys)
{
PruneStepResult *result = (PruneStepResult *) palloc0(sizeof(PruneStepResult));
PartitionBoundInfo boundinfo = context->boundinfo;
int *partindices = boundinfo->indexes;
int partnatts = context->partnatts;
bool isnull[PARTITION_MAX_KEYS];
int i;
uint64 rowHash;
int greatest_modulus;
Assert(context->strategy == PARTITION_STRATEGY_HASH);
/*
* For hash partitioning we can only perform pruning based on equality
* clauses to the partition key or IS NULL clauses. We also can only
* prune if we got values for all keys.
*/
if (nvalues + bms_num_members(nullkeys) == partnatts)
{
/*
* If there are any values, they must have come from clauses
* containing an equality operator compatible with hash partitioning.
*/
Assert(opstrategy == HTEqualStrategyNumber || nvalues == 0);
for (i = 0; i < partnatts; i++)
isnull[i] = bms_is_member(i, nullkeys);
greatest_modulus = get_hash_partition_greatest_modulus(boundinfo);
rowHash = compute_partition_hash_value(partnatts, partsupfunc,
values, isnull);
if (partindices[rowHash % greatest_modulus] >= 0)
result->bound_offsets =
bms_make_singleton(rowHash % greatest_modulus);
}
else
result->bound_offsets = bms_add_range(NULL, 0,
boundinfo->ndatums - 1);
/*
* There is neither a special hash null partition or the default hash
* partition.
*/
result->scan_null = result->scan_default = false;
return result;
}
/*
* get_matching_list_bounds
* Determine the offsets of list bounds matching the specified value,
* according to the semantics of the given operator strategy
* 'opstrategy' if non-zero must be a btree strategy number.
*
* 'value' contains the value to use for pruning.
*
* 'nvalues', if non-zero, should be exactly 1, because of list partitioning.
*
* 'partsupfunc' contains the list partitioning comparison function to be used
* to perform partition_list_bsearch
*
* 'nullkeys' is the set of partition keys that are null.
*/
static PruneStepResult *
get_matching_list_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum value, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys)
{
PruneStepResult *result = (PruneStepResult *) palloc0(sizeof(PruneStepResult));
PartitionBoundInfo boundinfo = context->boundinfo;
int off,
minoff,
maxoff;
bool is_equal;
bool inclusive = false;
Oid *partcollation = context->partcollation;
Assert(context->strategy == PARTITION_STRATEGY_LIST);
Assert(context->partnatts == 1);
result->scan_null = result->scan_default = false;
if (!bms_is_empty(nullkeys))
{
/*
* Nulls may exist in only one partition - the partition whose
* accepted set of values includes null or the default partition if
* the former doesn't exist.
*/
if (partition_bound_accepts_nulls(boundinfo))
result->scan_null = true;
else
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
/*
* If there are no datums to compare keys with, but there are partitions,
* just return the default partition if one exists.
*/
if (boundinfo->ndatums == 0)
{
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
minoff = 0;
maxoff = boundinfo->ndatums - 1;
/*
* If there are no values to compare with the datums in boundinfo, it
* means the caller asked for partitions for all non-null datums. Add
* indexes of *all* partitions, including the default if any.
*/
if (nvalues == 0)
{
result->bound_offsets = bms_add_range(NULL, 0,
boundinfo->ndatums - 1);
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
/* Special case handling of values coming from a <> operator clause. */
if (opstrategy == InvalidStrategy)
{
/*
* First match to all bounds. We'll remove any matching datums below.
*/
result->bound_offsets = bms_add_range(NULL, 0,
boundinfo->ndatums - 1);
off = partition_list_bsearch(partsupfunc, partcollation, boundinfo,
value, &is_equal);
if (off >= 0 && is_equal)
{
/* We have a match. Remove from the result. */
Assert(boundinfo->indexes[off] >= 0);
result->bound_offsets = bms_del_member(result->bound_offsets,
off);
}
/* Always include the default partition if any. */
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
/*
* With range queries, always include the default list partition, because
* list partitions divide the key space in a discontinuous manner, not all
* values in the given range will have a partition assigned. This may not
* technically be true for some data types (e.g. integer types), however,
* we currently lack any sort of infrastructure to provide us with proofs
* that would allow us to do anything smarter here.
*/
if (opstrategy != BTEqualStrategyNumber)
result->scan_default = partition_bound_has_default(boundinfo);
switch (opstrategy)
{
case BTEqualStrategyNumber:
off = partition_list_bsearch(partsupfunc,
partcollation,
boundinfo, value,
&is_equal);
if (off >= 0 && is_equal)
{
Assert(boundinfo->indexes[off] >= 0);
result->bound_offsets = bms_make_singleton(off);
}
else
result->scan_default = partition_bound_has_default(boundinfo);
return result;
case BTGreaterEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTGreaterStrategyNumber:
off = partition_list_bsearch(partsupfunc,
partcollation,
boundinfo, value,
&is_equal);
if (off >= 0)
{
/* We don't want the matched datum to be in the result. */
if (!is_equal || !inclusive)
off++;
}
else
{
/*
* This case means all partition bounds are greater, which in
* turn means that all partitions satisfy this key.
*/
off = 0;
}
/*
* off is greater than the numbers of datums we have partitions
* for. The only possible partition that could contain a match is
* the default partition, but we must've set context->scan_default
* above anyway if one exists.
*/
if (off > boundinfo->ndatums - 1)
return result;
minoff = off;
break;
case BTLessEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTLessStrategyNumber:
off = partition_list_bsearch(partsupfunc,
partcollation,
boundinfo, value,
&is_equal);
if (off >= 0 && is_equal && !inclusive)
off--;
/*
* off is smaller than the datums of all non-default partitions.
* The only possible partition that could contain a match is the
* default partition, but we must've set context->scan_default
* above anyway if one exists.
*/
if (off < 0)
return result;
maxoff = off;
break;
default:
elog(ERROR, "invalid strategy number %d", opstrategy);
break;
}
result->bound_offsets = bms_add_range(NULL, minoff, maxoff);
return result;
}
/*
* get_matching_range_datums
* Determine the offsets of range bounds matching the specified values,
* according to the semantics of the given operator strategy
*
* Each datum whose offset is in result is to be treated as the upper bound of
* the partition that will contain the desired values.
*
* If default partition needs to be scanned for given values, set scan_default
* in result if present.
*
* 'opstrategy' if non-zero must be a btree strategy number.
*
* 'values' contains Datums indexed by the partition key to use for pruning.
*
* 'nvalues', number of Datums in 'values' array. Must be <= context->partnatts.
*
* 'partsupfunc' contains the range partitioning comparison functions to be
* used to perform partition_range_datum_bsearch or partition_rbound_datum_cmp
* using.
*
* 'nullkeys' is the set of partition keys that are null.
*/
static PruneStepResult *
get_matching_range_bounds(PartitionPruneContext *context,
StrategyNumber opstrategy, Datum *values, int nvalues,
FmgrInfo *partsupfunc, Bitmapset *nullkeys)
{
PruneStepResult *result = (PruneStepResult *) palloc0(sizeof(PruneStepResult));
PartitionBoundInfo boundinfo = context->boundinfo;
Oid *partcollation = context->partcollation;
int partnatts = context->partnatts;
int *partindices = boundinfo->indexes;
int off,
minoff,
maxoff,
i;
bool is_equal;
bool inclusive = false;
Assert(context->strategy == PARTITION_STRATEGY_RANGE);
Assert(nvalues <= partnatts);
result->scan_null = result->scan_default = false;
/*
* If there are no datums to compare keys with, or if we got an IS NULL
* clause just return the default partition, if it exists.
*/
if (boundinfo->ndatums == 0 || !bms_is_empty(nullkeys))
{
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
minoff = 0;
maxoff = boundinfo->ndatums;
/*
* If there are no values to compare with the datums in boundinfo, it
* means the caller asked for partitions for all non-null datums. Add
* indexes of *all* partitions, including the default partition if one
* exists.
*/
if (nvalues == 0)
{
if (partindices[minoff] < 0)
minoff++;
if (partindices[maxoff] < 0)
maxoff--;
result->scan_default = partition_bound_has_default(boundinfo);
result->bound_offsets = bms_add_range(NULL, minoff, maxoff);
return result;
}
/*
* If the query does not constrain all key columns, we'll need to scan the
* the default partition, if any.
*/
if (nvalues < partnatts)
result->scan_default = partition_bound_has_default(boundinfo);
switch (opstrategy)
{
case BTEqualStrategyNumber:
/* Look for the smallest bound that is = lookup value. */
off = partition_range_datum_bsearch(partsupfunc,
partcollation,
boundinfo,
nvalues, values,
&is_equal);
if (off >= 0 && is_equal)
{
if (nvalues == partnatts)
{
/* There can only be zero or one matching partition. */
if (partindices[off + 1] >= 0)
result->bound_offsets = bms_make_singleton(off + 1);
else
result->scan_default =
partition_bound_has_default(boundinfo);
return result;
}
else
{
int saved_off = off;
/*
* Since the lookup value contains only a prefix of keys,
* we must find other bounds that may also match the
* prefix. partition_range_datum_bsearch() returns the
* offset of one of them, find others by checking adjacent
* bounds.
*/
/*
* First find greatest bound that's smaller than the
* lookup value.
*/
while (off >= 1)
{
int32 cmpval;
cmpval =
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off - 1],
boundinfo->kind[off - 1],
values, nvalues);
if (cmpval != 0)
break;
off--;
}
Assert(0 ==
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off],
boundinfo->kind[off],
values, nvalues));
/*
* We can treat 'off' as the offset of the smallest bound
* to be included in the result, if we know it is the
* upper bound of the partition in which the lookup value
* could possibly exist. One case it couldn't is if the
* bound, or precisely the matched portion of its prefix,
* is not inclusive.
*/
if (boundinfo->kind[off][nvalues] ==
PARTITION_RANGE_DATUM_MINVALUE)
off++;
minoff = off;
/*
* Now find smallest bound that's greater than the lookup
* value.
*/
off = saved_off;
while (off < boundinfo->ndatums - 1)
{
int32 cmpval;
cmpval = partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off + 1],
boundinfo->kind[off + 1],
values, nvalues);
if (cmpval != 0)
break;
off++;
}
Assert(0 ==
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off],
boundinfo->kind[off],
values, nvalues));
/*
* off + 1, then would be the offset of the greatest bound
* to be included in the result.
*/
maxoff = off + 1;
}
/*
* Skip if minoff/maxoff are actually the upper bound of a
* un-assigned portion of values.
*/
if (partindices[minoff] < 0 && minoff < boundinfo->ndatums)
minoff++;
if (partindices[maxoff] < 0 && maxoff >= 1)
maxoff--;
/*
* There may exist a range of values unassigned to any
* non-default partition between the datums at minoff and
* maxoff. Add the default partition in that case.
*/
if (partition_bound_has_default(boundinfo))
{
for (i = minoff; i <= maxoff; i++)
{
if (partindices[i] < 0)
{
result->scan_default = true;
break;
}
}
}
Assert(minoff >= 0 && maxoff >= 0);
result->bound_offsets = bms_add_range(NULL, minoff, maxoff);
}
else if (off >= 0) /* !is_equal */
{
/*
* The lookup value falls in the range between some bounds in
* boundinfo. 'off' would be the offset of the greatest bound
* that is <= lookup value, so add off + 1 to the result
* instead as the offset of the upper bound of the only
* partition that may contain the lookup value.
*/
if (partindices[off + 1] >= 0)
result->bound_offsets = bms_make_singleton(off + 1);
else
result->scan_default =
partition_bound_has_default(boundinfo);
}
else
{
/*
* off < 0: the lookup value is smaller than all bounds, so
* only the default partition qualifies, if there is one.
*/
result->scan_default = partition_bound_has_default(boundinfo);
}
return result;
case BTGreaterEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTGreaterStrategyNumber:
/*
* Look for the smallest bound that is > or >= lookup value and
* set minoff to its offset.
*/
off = partition_range_datum_bsearch(partsupfunc,
partcollation,
boundinfo,
nvalues, values,
&is_equal);
if (off < 0)
{
/*
* All bounds are greater than the lookup value, so include
* all of them in the result.
*/
minoff = 0;
}
else
{
if (is_equal && nvalues < partnatts)
{
/*
* Since the lookup value contains only a prefix of keys,
* we must find other bounds that may also match the
* prefix. partition_range_datum_bsearch() returns the
* offset of one of them, find others by checking adjacent
* bounds.
*
* Based on whether the lookup values are inclusive or
* not, we must either include the indexes of all such
* bounds in the result (that is, set minoff to the index
* of smallest such bound) or find the smallest one that's
* greater than the lookup values and set minoff to that.
*/
while (off >= 1 && off < boundinfo->ndatums - 1)
{
int32 cmpval;
int nextoff;
nextoff = inclusive ? off - 1 : off + 1;
cmpval =
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[nextoff],
boundinfo->kind[nextoff],
values, nvalues);
if (cmpval != 0)
break;
off = nextoff;
}
Assert(0 ==
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off],
boundinfo->kind[off],
values, nvalues));
minoff = inclusive ? off : off + 1;
}
/*
* lookup value falls in the range between some bounds in
* boundinfo. off would be the offset of the greatest bound
* that is <= lookup value, so add off + 1 to the result
* instead as the offset of the upper bound of the smallest
* partition that may contain the lookup value.
*/
else
minoff = off + 1;
}
break;
case BTLessEqualStrategyNumber:
inclusive = true;
/* fall through */
case BTLessStrategyNumber:
/*
* Look for the greatest bound that is < or <= lookup value and
* set minoff to its offset.
*/
off = partition_range_datum_bsearch(partsupfunc,
partcollation,
boundinfo,
nvalues, values,
&is_equal);
if (off < 0)
{
/*
* All bounds are greater than the key, so we could only
* expect to find the lookup key in the default partition.
*/
result->scan_default = partition_bound_has_default(boundinfo);
return result;
}
else
{
/*
* See the comment above.
*/
if (is_equal && nvalues < partnatts)
{
while (off >= 1 && off < boundinfo->ndatums - 1)
{
int32 cmpval;
int nextoff;
nextoff = inclusive ? off + 1 : off - 1;
cmpval = partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[nextoff],
boundinfo->kind[nextoff],
values, nvalues);
if (cmpval != 0)
break;
off = nextoff;
}
Assert(0 ==
partition_rbound_datum_cmp(partsupfunc,
partcollation,
boundinfo->datums[off],
boundinfo->kind[off],
values, nvalues));
maxoff = inclusive ? off + 1 : off;
}
/*
* The lookup value falls in the range between some bounds in
* boundinfo. 'off' would be the offset of the greatest bound
* that is <= lookup value, so add off + 1 to the result
* instead as the offset of the upper bound of the greatest
* partition that may contain lookup value. If the lookup
* value had exactly matched the bound, but it isn't
* inclusive, no need add the adjacent partition.
*/
else if (!is_equal || inclusive)
maxoff = off + 1;
else
maxoff = off;
}
break;
default:
elog(ERROR, "invalid strategy number %d", opstrategy);
break;
}
/*
* Skip a gap and when doing so, check if the bound contains a finite
* value to decide if we need to add the default partition. If it's an
* infinite bound, we need not add the default partition, as having an
* infinite bound means the partition in question catches any values that
* would otherwise be in the default partition.
*/
if (partindices[minoff] < 0)
{
int lastkey = nvalues - 1;
if (minoff >= 0 &&
minoff < boundinfo->ndatums &&
boundinfo->kind[minoff][lastkey] ==
PARTITION_RANGE_DATUM_VALUE)
result->scan_default = partition_bound_has_default(boundinfo);
minoff++;
}
/*
* Skip a gap. See the above comment about how we decide whether or or
* not to scan the default partition based whether the datum that will
* become the maximum datum is finite or not.
*/
if (maxoff >= 1 && partindices[maxoff] < 0)
{
int lastkey = nvalues - 1;
if (maxoff >= 0 &&
maxoff <= boundinfo->ndatums &&
boundinfo->kind[maxoff - 1][lastkey] ==
PARTITION_RANGE_DATUM_VALUE)
result->scan_default = partition_bound_has_default(boundinfo);
maxoff--;
}
if (partition_bound_has_default(boundinfo))
{
/*
* There may exist a range of values unassigned to any non-default
* partition between the datums at minoff and maxoff. Add the default
* partition in that case.
*/
for (i = minoff; i <= maxoff; i++)
{
if (partindices[i] < 0)
{
result->scan_default = true;
break;
}
}
}
Assert(minoff >= 0 && maxoff >= 0);
if (minoff <= maxoff)
result->bound_offsets = bms_add_range(NULL, minoff, maxoff);
return result;
}
/*
* pull_exec_paramids
* Returns a Bitmapset containing the paramids of all Params with
* paramkind = PARAM_EXEC in 'expr'.
*/
static Bitmapset *
pull_exec_paramids(Expr *expr)
{
Bitmapset *result = NULL;
(void) pull_exec_paramids_walker((Node *) expr, &result);
return result;
}
static bool
pull_exec_paramids_walker(Node *node, Bitmapset **context)
{
if (node == NULL)
return false;
if (IsA(node, Param))
{
Param *param = (Param *) node;
if (param->paramkind == PARAM_EXEC)
*context = bms_add_member(*context, param->paramid);
return false;
}
return expression_tree_walker(node, pull_exec_paramids_walker,
(void *) context);
}
/*
* analyze_partkey_exprs
* Loop through all pruning steps and identify which ones require
* executor startup-time or executor run-time pruning.
*
* Returns true if any executor partition pruning should be attempted at this
* level. Also fills fields of *pinfo to record how to process each step.
*/
static bool
analyze_partkey_exprs(PartitionPruneInfo *pinfo, List *steps, int partnatts)
{
bool doruntimeprune = false;
ListCell *lc;
/*
* Steps require run-time pruning if they contain EXEC_PARAM Params.
* Otherwise, if their expressions aren't simple Consts, they require
* startup-time pruning.
*/
pinfo->nexprs = list_length(steps) * partnatts;
pinfo->hasexecparam = (bool *) palloc0(sizeof(bool) * pinfo->nexprs);
pinfo->do_initial_prune = false;
pinfo->do_exec_prune = false;
pinfo->execparamids = NULL;
foreach(lc, steps)
{
PartitionPruneStepOp *step = (PartitionPruneStepOp *) lfirst(lc);
ListCell *lc2;
int keyno;
if (!IsA(step, PartitionPruneStepOp))
continue;
keyno = 0;
foreach(lc2, step->exprs)
{
Expr *expr = lfirst(lc2);
if (!IsA(expr, Const))
{
Bitmapset *execparamids = pull_exec_paramids(expr);
bool hasexecparams;
int stateidx = PruneCxtStateIdx(partnatts,
step->step.step_id,
keyno);
Assert(stateidx < pinfo->nexprs);
hasexecparams = !bms_is_empty(execparamids);
pinfo->hasexecparam[stateidx] = hasexecparams;
pinfo->execparamids = bms_join(pinfo->execparamids,
execparamids);
if (hasexecparams)
pinfo->do_exec_prune = true;
else
pinfo->do_initial_prune = true;
doruntimeprune = true;
}
keyno++;
}
}
return doruntimeprune;
}
/*
* perform_pruning_base_step
* Determines the indexes of datums that satisfy conditions specified in
* 'opstep'.
*
* Result also contains whether special null-accepting and/or default
* partition need to be scanned.
*/
static PruneStepResult *
perform_pruning_base_step(PartitionPruneContext *context,
PartitionPruneStepOp *opstep)
{
ListCell *lc1,
*lc2;
int keyno,
nvalues;
Datum values[PARTITION_MAX_KEYS];
FmgrInfo *partsupfunc;
int stateidx;
/*
* There better be the same number of expressions and compare functions.
*/
Assert(list_length(opstep->exprs) == list_length(opstep->cmpfns));
nvalues = 0;
lc1 = list_head(opstep->exprs);
lc2 = list_head(opstep->cmpfns);
/*
* Generate the partition lookup key that will be used by one of the
* get_matching_*_bounds functions called below.
*/
for (keyno = 0; keyno < context->partnatts; keyno++)
{
/*
* For hash partitioning, it is possible that values of some keys are
* not provided in operator clauses, but instead the planner found
* that they appeared in a IS NULL clause.
*/
if (bms_is_member(keyno, opstep->nullkeys))
continue;
/*
* For range partitioning, we must only perform pruning with values
* for either all partition keys or a prefix thereof.
*/
if (keyno > nvalues && context->strategy == PARTITION_STRATEGY_RANGE)
break;
if (lc1 != NULL)
{
Expr *expr;
Datum datum;
bool isnull;
expr = lfirst(lc1);
stateidx = PruneCxtStateIdx(context->partnatts,
opstep->step.step_id, keyno);
if (partkey_datum_from_expr(context, expr, stateidx,
&datum, &isnull))
{
Oid cmpfn;
/*
* Since we only allow strict operators in pruning steps, any
* null-valued comparison value must cause the comparison to
* fail, so that no partitions could match.
*/
if (isnull)
{
PruneStepResult *result;
result = (PruneStepResult *) palloc(sizeof(PruneStepResult));
result->bound_offsets = NULL;
result->scan_default = false;
result->scan_null = false;
return result;
}
/* Set up the stepcmpfuncs entry, unless we already did */
cmpfn = lfirst_oid(lc2);
Assert(OidIsValid(cmpfn));
if (cmpfn != context->stepcmpfuncs[stateidx].fn_oid)
{
/*
* If the needed support function is the same one cached
* in the relation's partition key, copy the cached
* FmgrInfo. Otherwise (i.e., when we have a cross-type
* comparison), an actual lookup is required.
*/
if (cmpfn == context->partsupfunc[keyno].fn_oid)
fmgr_info_copy(&context->stepcmpfuncs[stateidx],
&context->partsupfunc[keyno],
context->ppccontext);
else
fmgr_info_cxt(cmpfn, &context->stepcmpfuncs[stateidx],
context->ppccontext);
}
values[keyno] = datum;
nvalues++;
}
lc1 = lnext(lc1);
lc2 = lnext(lc2);
}
}
/*
* Point partsupfunc to the entry for the 0th key of this step; the
* additional support functions, if any, follow consecutively.
*/
stateidx = PruneCxtStateIdx(context->partnatts, opstep->step.step_id, 0);
partsupfunc = &context->stepcmpfuncs[stateidx];
switch (context->strategy)
{
case PARTITION_STRATEGY_HASH:
return get_matching_hash_bounds(context,
opstep->opstrategy,
values, nvalues,
partsupfunc,
opstep->nullkeys);
case PARTITION_STRATEGY_LIST:
return get_matching_list_bounds(context,
opstep->opstrategy,
values[0], nvalues,
&partsupfunc[0],
opstep->nullkeys);
case PARTITION_STRATEGY_RANGE:
return get_matching_range_bounds(context,
opstep->opstrategy,
values, nvalues,
partsupfunc,
opstep->nullkeys);
default:
elog(ERROR, "unexpected partition strategy: %d",
(int) context->strategy);
break;
}
return NULL;
}
/*
* perform_pruning_combine_step
* Determines the indexes of datums obtained by combining those given
* by the steps identified by cstep->source_stepids using the specified
* combination method
*
* Since cstep may refer to the result of earlier steps, we also receive
* step_results here.
*/
static PruneStepResult *
perform_pruning_combine_step(PartitionPruneContext *context,
PartitionPruneStepCombine *cstep,
PruneStepResult **step_results)
{
ListCell *lc1;
PruneStepResult *result = NULL;
bool firststep;
/*
* A combine step without any source steps is an indication to not perform
* any partition pruning, we just return all partitions.
*/
result = (PruneStepResult *) palloc0(sizeof(PruneStepResult));
if (list_length(cstep->source_stepids) == 0)
{
PartitionBoundInfo boundinfo = context->boundinfo;
result->bound_offsets = bms_add_range(NULL, 0, boundinfo->ndatums - 1);
result->scan_default = partition_bound_has_default(boundinfo);
result->scan_null = partition_bound_accepts_nulls(boundinfo);
return result;
}
switch (cstep->combineOp)
{
case PARTPRUNE_COMBINE_UNION:
foreach(lc1, cstep->source_stepids)
{
int step_id = lfirst_int(lc1);
PruneStepResult *step_result;
/*
* step_results[step_id] must contain a valid result, which is
* confirmed by the fact that cstep's step_id is greater than
* step_id and the fact that results of the individual steps
* are evaluated in sequence of their step_ids.
*/
if (step_id >= cstep->step.step_id)
elog(ERROR, "invalid pruning combine step argument");
step_result = step_results[step_id];
Assert(step_result != NULL);
/* Record any additional datum indexes from this step */
result->bound_offsets = bms_add_members(result->bound_offsets,
step_result->bound_offsets);
/* Update whether to scan null and default partitions. */
if (!result->scan_null)
result->scan_null = step_result->scan_null;
if (!result->scan_default)
result->scan_default = step_result->scan_default;
}
break;
case PARTPRUNE_COMBINE_INTERSECT:
firststep = true;
foreach(lc1, cstep->source_stepids)
{
int step_id = lfirst_int(lc1);
PruneStepResult *step_result;
if (step_id >= cstep->step.step_id)
elog(ERROR, "invalid pruning combine step argument");
step_result = step_results[step_id];
Assert(step_result != NULL);
if (firststep)
{
/* Copy step's result the first time. */
result->bound_offsets =
bms_copy(step_result->bound_offsets);
result->scan_null = step_result->scan_null;
result->scan_default = step_result->scan_default;
firststep = false;
}
else
{
/* Record datum indexes common to both steps */
result->bound_offsets =
bms_int_members(result->bound_offsets,
step_result->bound_offsets);
/* Update whether to scan null and default partitions. */
if (result->scan_null)
result->scan_null = step_result->scan_null;
if (result->scan_default)
result->scan_default = step_result->scan_default;
}
}
break;
}
return result;
}
/*
* match_boolean_partition_clause
*
* Sets *outconst to a Const containing true or false value and returns true if
* we're able to match the clause to the partition key as specially-shaped
* Boolean clause. Returns false otherwise with *outconst set to NULL.
*/
static bool
match_boolean_partition_clause(Oid partopfamily, Expr *clause, Expr *partkey,
Expr **outconst)
{
Expr *leftop;
*outconst = NULL;
if (!IsBooleanOpfamily(partopfamily))
return false;
if (IsA(clause, BooleanTest))
{
BooleanTest *btest = (BooleanTest *) clause;
/* Only IS [NOT] TRUE/FALSE are any good to us */
if (btest->booltesttype == IS_UNKNOWN ||
btest->booltesttype == IS_NOT_UNKNOWN)
return false;
leftop = btest->arg;
if (IsA(leftop, RelabelType))
leftop = ((RelabelType *) leftop)->arg;
if (equal(leftop, partkey))
*outconst = (btest->booltesttype == IS_TRUE ||
btest->booltesttype == IS_NOT_FALSE)
? (Expr *) makeBoolConst(true, false)
: (Expr *) makeBoolConst(false, false);
if (*outconst)
return true;
}
else
{
bool is_not_clause = not_clause((Node *) clause);
leftop = is_not_clause ? get_notclausearg(clause) : clause;
if (IsA(leftop, RelabelType))
leftop = ((RelabelType *) leftop)->arg;
/* Compare to the partition key, and make up a clause ... */
if (equal(leftop, partkey))
*outconst = is_not_clause ?
(Expr *) makeBoolConst(false, false) :
(Expr *) makeBoolConst(true, false);
else if (equal(negate_clause((Node *) leftop), partkey))
*outconst = (Expr *) makeBoolConst(false, false);
if (*outconst)
return true;
}
return false;
}
/*
* partkey_datum_from_expr
* Evaluate expression for potential partition pruning
*
* Evaluate 'expr', whose ExprState is stateidx of the context exprstate
* array; set *value and *isnull to the resulting Datum and nullflag.
* Return true if evaluation was possible, otherwise false.
*
* Note that the evaluated result may be in the per-tuple memory context of
* context->planstate->ps_ExprContext, and we may have leaked other memory
* there too. This memory must be recovered by resetting that ExprContext
* after we're done with the pruning operation (see execPartition.c).
*/
static bool
partkey_datum_from_expr(PartitionPruneContext *context,
Expr *expr, int stateidx,
Datum *value, bool *isnull)
{
if (IsA(expr, Const))
{
/* We can always determine the value of a constant */
Const *con = (Const *) expr;
*value = con->constvalue;
*isnull = con->constisnull;
return true;
}
else
{
/*
* When called from the executor we'll have a valid planstate so we
* may be able to evaluate an expression which could not be folded to
* a Const during planning. Since run-time pruning can occur both
* during initialization of the executor or while it's running, we
* must be careful here to evaluate expressions containing PARAM_EXEC
* Params only when told it's OK.
*/
if (context->planstate &&
(context->evalexecparams ||
!context->exprhasexecparam[stateidx]))
{
ExprState *exprstate;
ExprContext *ectx;
exprstate = context->exprstates[stateidx];
ectx = context->planstate->ps_ExprContext;
*value = ExecEvalExprSwitchContext(exprstate, ectx, isnull);
return true;
}
}
return false;
}
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