217 Commits

Author SHA1 Message Date
Tom Lane
fb30ac54e6 Thinking further, it seems we had better also copy down resorigtbl/resorigcol
to ensure that SubqueryScan elimination doesn't change the behavior of
reporting of original column sources.
2005-11-03 17:45:29 +00:00
Tom Lane
abf293e155 Fix the recently-added code that eliminates unnecessary SubqueryScan nodes
from a finished plan tree.  We have to copy the output column names
(resname fields) from the SubqueryScan down to its child plan node;
else, if this is the topmost level of the plan, the wrong column names
will be delivered to the client.  Per bug #2017 reported by Jolly Chen.
2005-11-03 17:34:03 +00:00
Bruce Momjian
1dc3498251 Standard pgindent run for 8.1. 2005-10-15 02:49:52 +00:00
Tom Lane
e35e6b1c37 Back out prior patch and instead just suppress SubqueryScan elimination
when there are extra resjunk columns in the child node.  I found some
additional cases involving Append nodes that weren't handled by the
prior patch, and it's not clear how to fix them in the same way without
breaking inheritance cases.  So the prudent path seems to be to narrow
the scope of the optimization.
2005-09-05 18:59:38 +00:00
Tom Lane
03728942c2 For non-projecting plan node types such as Limit, set_plan_references
has to recopy the input plan node's targetlist if it removes a
SubqueryScan node just below the non-projecting node.  For simplicity
I made it recopy always.  Per bug report from Allan Wang and Michael Fuhr.
2005-09-05 17:25:01 +00:00
Tom Lane
5a7d36973a Fix two separate bugs in setrefs.c. set_subqueryscan_references needs
to copy the whole plan tree before invoking adjust_plan_varnos(); else
if there is any multiply-linked substructure, the latter might increment
some Var's varno twice.  Previously there were some retail copyObject
calls inside adjust_plan_varnos, but it seems a lot safer to just dup the
whole tree first.  Also, set_inner_join_references was trying to avoid
work by not recursing if a BitmapHeapScan's bitmapqualorig contained no
outer references; which was OK at the time the code was written, I think,
but now that create_bitmap_scan_plan removes duplicate clauses from
bitmapqualorig it is possible for that field to be NULL while outer
references still remain in the qpqual and/or contained indexscan nodes.
For safety, always recurse even if the BitmapHeapScan looks to be outer
reference free.  Per reports from Michael Fuhr and Oleg Bartunov.
2005-08-27 18:04:49 +00:00
Tom Lane
39cee73889 Revise searching of subplan target lists to use something more efficient
than tlist_member calls.  Building a large join tlist is still O(N^2),
but with a much smaller constant factor than before.
2005-06-10 00:28:54 +00:00
Tom Lane
e2159f3842 Teach the planner to remove SubqueryScan nodes from the plan if they
aren't doing anything useful (ie, neither selection nor projection).
Also, extend to SubqueryScan the hacks already in place to avoid
unnecessary ExecProject calls when the result would just be the same
tuple the subquery already delivered.  This saves some overhead in
UNION and other set operations, as well as avoiding overhead for
unflatten-able subqueries.  Per example from Sokolov Yura.
2005-05-22 22:30:20 +00:00
Tom Lane
5b05185262 Remove support for OR'd indexscans internal to a single IndexScan plan
node, as this behavior is now better done as a bitmap OR indexscan.
This allows considerable simplification in nodeIndexscan.c itself as
well as several planner modules concerned with indexscan plan generation.
Also we can improve the sharing of code between regular and bitmap
indexscans, since they are now working with nigh-identical Plan nodes.
2005-04-25 01:30:14 +00:00
Tom Lane
bc843d3960 First cut at planner support for bitmap index scans. Lots to do yet,
but the code is basically working.  Along the way, rewrite the entire
approach to processing OR index conditions, and make it work in join
cases for the first time ever.  orindxpath.c is now basically obsolete,
but I left it in for the time being to allow easy comparison testing
against the old implementation.
2005-04-22 21:58:32 +00:00
Tom Lane
4a8c5d0375 Create executor and planner-backend support for decoupled heap and index
scans, using in-memory tuple ID bitmaps as the intermediary.  The planner
frontend (path creation and cost estimation) is not there yet, so none
of this code can be executed.  I have tested it using some hacked planner
code that is far too ugly to see the light of day, however.  Committing
now so that the bulk of the infrastructure changes go in before the tree
drifts under me.
2005-04-19 22:35:18 +00:00
Tom Lane
ad161bcc8a Merge Resdom nodes into TargetEntry nodes to simplify code and save a
few palloc's.  I also chose to eliminate the restype and restypmod fields
entirely, since they are redundant with information stored in the node's
contained expression; re-examining the expression at need seems simpler
and more reliable than trying to keep restype/restypmod up to date.

initdb forced due to change in contents of stored rules.
2005-04-06 16:34:07 +00:00
PostgreSQL Daemon
2ff501590b Tag appropriate files for rc3
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
2004-12-31 22:04:05 +00:00
Bruce Momjian
b6b71b85bc Pgindent run for 8.0. 2004-08-29 05:07:03 +00:00
Bruce Momjian
da9a8649d8 Update copyright to 2004. 2004-08-29 04:13:13 +00:00
Neil Conway
d0b4399d81 Reimplement the linked list data structure used throughout the backend.
In the past, we used a 'Lispy' linked list implementation: a "list" was
merely a pointer to the head node of the list. The problem with that
design is that it makes lappend() and length() linear time. This patch
fixes that problem (and others) by maintaining a count of the list
length and a pointer to the tail node along with each head node pointer.
A "list" is now a pointer to a structure containing some meta-data
about the list; the head and tail pointers in that structure refer
to ListCell structures that maintain the actual linked list of nodes.

The function names of the list API have also been changed to, I hope,
be more logically consistent. By default, the old function names are
still available; they will be disabled-by-default once the rest of
the tree has been updated to use the new API names.
2004-05-26 04:41:50 +00:00
Tom Lane
bef764029b Fix oversights in processing of LIMIT expressions during planning. 2004-05-11 13:15:15 +00:00
Tom Lane
b0c4a50bbb Instead of rechecking lossy index operators by putting them into the
regular qpqual ('filter condition'), add special-purpose code to
nodeIndexscan.c to recheck them.  This ends being almost no net addition
of code, because the removal of planner code balances out the extra
executor code, but it is significantly more efficient when a lossy
operator is involved in an OR indexscan.  The old implementation had
to recheck the entire indexqual in such cases.
2004-01-06 04:31:01 +00:00
PostgreSQL Daemon
969685ad44 $Header: -> $PostgreSQL Changes ... 2003-11-29 19:52:15 +00:00
Tom Lane
a64846f3ad Get rid of hashkeys field of Hash plan node, since it's redundant with
the hashclauses field of the parent HashJoin.  This avoids problems with
duplicated links to SubPlans in hash clauses, as per report from
Andrew Holm-Hansen.
2003-11-25 21:00:54 +00:00
Bruce Momjian
46785776c4 Another pgindent run with updated typedefs. 2003-08-08 21:42:59 +00:00
Bruce Momjian
f3c3deb7d0 Update copyrights to 2003. 2003-08-04 02:40:20 +00:00
Bruce Momjian
089003fb46 pgindent run. 2003-08-04 00:43:34 +00:00
Tom Lane
45708f5ebc Error message editing in backend/optimizer, backend/rewrite. 2003-07-25 00:01:09 +00:00
Tom Lane
bee217924d Support expressions of the form 'scalar op ANY (array)' and
'scalar op ALL (array)', where the operator is applied between the
lefthand scalar and each element of the array.  The operator must
yield boolean; the result of the construct is the OR or AND of the
per-element results, respectively.

Original coding by Joe Conway, after an idea of Peter's.  Rewritten
by Tom to keep the implementation strictly separate from subqueries.
2003-06-29 00:33:44 +00:00
Tom Lane
51972a9d5d COALESCE() and NULLIF() are now first-class expressions, not macros
that turn into CASE expressions.  They evaluate their arguments at most
once.  Patch by Kris Jurka, review and (very light) editorializing by me.
2003-02-16 02:30:39 +00:00
Tom Lane
bdfbfde1b1 IN clauses appearing at top level of WHERE can now be handled as joins.
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
2003-01-20 18:55:07 +00:00
Tom Lane
cde9f852e0 Now that switch_outer processing no longer relies on being run after
join_references(), it's practical to consolidate all join_references()
processing into the set_plan_references traversal in setrefs.c.  This
seems considerably cleaner than the old way where we did it for join
quals in createplan.c and for targetlists in setrefs.c.
2003-01-15 23:10:32 +00:00
Tom Lane
de97072e3c Allow merge and hash joins to occur on arbitrary expressions (anything not
containing a volatile function), rather than only on 'Var = Var' clauses
as before.  This makes it practical to do flatten_join_alias_vars at the
start of planning, which in turn eliminates a bunch of klugery inside the
planner to deal with alias vars.  As a free side effect, we now detect
implied equality of non-Var expressions; for example in
	SELECT ... WHERE a.x = b.y and b.y = 42
we will deduce a.x = 42 and use that as a restriction qual on a.  Also,
we can remove the restriction introduced 12/5/02 to prevent pullup of
subqueries whose targetlists contain sublinks.
Still TODO: make statistical estimation routines in selfuncs.c and costsize.c
smarter about expressions that are more complex than plain Vars.  The need
for this is considerably greater now that we have to be able to estimate
the suitability of merge and hash join techniques on such expressions.
2003-01-15 19:35:48 +00:00
Tom Lane
56e1aab286 Reconsider mechanism for marking sub-selects that are at top level of
a qualification clause (and hence can get away with being sloppy about
distinguishing FALSE from UNKNOWN).  We need to know this in subselect.c;
marking the subplans in setrefs.c is too late.
2003-01-13 18:10:53 +00:00
Tom Lane
e69785debf Further tweaking of parsetree & plantree representation of SubLinks.
Simplify SubLink by storing just a List of operator OIDs, instead of
a list of incomplete OpExprs --- that was a bizarre and bulky choice,
with no redeeming social value since we have to build new OpExprs
anyway when forming the plan tree.
2003-01-10 21:08:15 +00:00
Tom Lane
2d8d66628a Clean up plantree representation of SubPlan-s --- SubLink does not appear
in the planned representation of a subplan at all any more, only SubPlan.
This means subselect.c doesn't scribble on its input anymore, which seems
like a good thing; and there are no longer three different possible
interpretations of a SubLink.  Simplify node naming and improve comments
in primnodes.h.  No change to stored rules, though.
2002-12-14 00:17:59 +00:00
Tom Lane
a0bf885f9e Phase 2 of read-only-plans project: restructure expression-tree nodes
so that all executable expression nodes inherit from a common supertype
Expr.  This is somewhat of an exercise in code purity rather than any
real functional advance, but getting rid of the extra Oper or Func node
formerly used in each operator or function call should provide at least
a little space and speed improvement.
initdb forced by changes in stored-rules representation.
2002-12-12 15:49:42 +00:00
Tom Lane
1fd0c59e25 Phase 1 of read-only-plans project: cause executor state nodes to point
to plan nodes, not vice-versa.  All executor state nodes now inherit from
struct PlanState.  Copying of plan trees has been simplified by not
storing a list of SubPlans in Plan nodes (eliminating duplicate links).
The executor still needs such a list, but it can build it during
ExecutorStart since it has to scan the plan tree anyway.
No initdb forced since no stored-on-disk structures changed, but you
will need a full recompile because of node-numbering changes.
2002-12-05 15:50:39 +00:00
Tom Lane
2b7ec402c4 Code review for IS DISTINCT FROM patch. Fix incorrect constant-folding
logic, dissuade planner from thinking that 'x IS DISTINCT FROM 42' may
be optimized into 'x = 42' (!!), cause dependency on = operator to be
recorded correctly, minor other improvements.
2002-11-30 21:25:08 +00:00
Tom Lane
b60be3f2f8 Add an at-least-marginally-plausible method of estimating the number
of groups produced by GROUP BY.  This improves the accuracy of planning
estimates for grouped subselects, and is needed to check whether a
hashed aggregation plan risks memory overflow.
2002-11-19 23:22:00 +00:00
Bruce Momjian
e50f52a074 pgindent run. 2002-09-04 20:31:48 +00:00
Bruce Momjian
97ac103289 Remove sys/types.h in files that include postgres.h, and hence c.h,
because c.h has sys/types.h.
2002-09-02 02:47:07 +00:00
Bruce Momjian
d84fe82230 Update copyright to 2002. 2002-06-20 20:29:54 +00:00
Tom Lane
51fd22abdd Change set_plan_references and join_references to take an rtable List
rather than a Query node; this allows set_plan_references to recurse
into subplans correctly.  Fixes core dump on full outer joins in
subplans.  Also, invoke preprocess_expression on function RTEs'
function expressions.  This seems to fix the planner's problems with
outer-level Vars in function RTEs.
2002-05-18 02:25:50 +00:00
Tom Lane
0a757154bd Add missing fix_expr_references() step for the funcexpr of a
FunctionScan plan node.
2002-05-18 00:42:55 +00:00
Tom Lane
f9e4f611a1 First pass at set-returning-functions in FROM, by Joe Conway with
some kibitzing from Tom Lane.  Not everything works yet, and there's
no documentation or regression test, but let's commit this so Joe
doesn't need to cope with tracking changes in so many files ...
2002-05-12 20:10:05 +00:00
Tom Lane
6c59886942 Second try at fixing join alias variables. Instead of attaching miscellaneous
lists to join RTEs, attach a list of Vars and COALESCE expressions that will
replace the join's alias variables during planning.  This simplifies
flatten_join_alias_vars while still making it easy to fix up varno references
when transforming the query tree.  Add regression test cases for interactions
of subqueries with outer joins.
2002-04-28 19:54:29 +00:00
Tom Lane
6eeb95f0f5 Restructure representation of join alias variables. An explicit JOIN
now has an RTE of its own, and references to its outputs now are Vars
referencing the JOIN RTE, rather than CASE-expressions.  This allows
reverse-listing in ruleutils.c to use the correct alias easily, rather
than painfully reverse-engineering the alias namespace as it used to do.
Also, nested FULL JOINs work correctly, because the result of the inner
joins are simple Vars that the planner can cope with.  This fixes a bug
reported a couple times now, notably by Tatsuo on 18-Nov-01.  The alias
Vars are expanded into COALESCE expressions where needed at the very end
of planning, rather than during parsing.
Also, beginnings of support for showing plan qualifier expressions in
EXPLAIN.  There are probably still cases that need work.
initdb forced due to change of stored-rule representation.
2002-03-12 00:52:10 +00:00
Bruce Momjian
ea08e6cd55 New pgindent run with fixes suggested by Tom. Patch manually reviewed,
initdb/regression tests pass.
2001-11-05 17:46:40 +00:00
Tom Lane
96ca8ffebc Fix problems with subselects used in GROUP BY expressions, per gripe
from Philip Warner.  Side effect of change is that GROUP BY expressions
will not be re-evaluated at multiple plan levels anymore, whereas this
sometimes happened with old code.
2001-10-30 19:58:58 +00:00
Bruce Momjian
9e1552607a pgindent run. Make it all clean. 2001-03-22 04:01:46 +00:00
Bruce Momjian
623bf843d2 Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group. 2001-01-24 19:43:33 +00:00
Tom Lane
07c741e61c Fix oversight in planning of GROUP queries: when an expression is used
as both a GROUP BY item and an output expression, the top-level Group
node should just copy up the evaluated expression value from its input,
rather than re-evaluating the expression.  Aside from any performance
benefit this might offer, this avoids a crash when there is a sub-SELECT
in said expression.
2001-01-09 03:48:51 +00:00
Tom Lane
2f35b4efdb Re-implement LIMIT/OFFSET as a plan node type, instead of a hack in
ExecutorRun.  This allows LIMIT to work in a view.  Also, LIMIT in a
cursor declaration will behave in a reasonable fashion, whereas before
it was overridden by the FETCH count.
2000-10-26 21:38:24 +00:00