sequence every time it's called is bogus --- it interferes with user
control over the seed, and actually decreases randomness overall
(because a seed based on time(NULL) is pretty predictable). If you really
want a reproducible result from geqo, do 'set seed = 0' before planning
a query.
on either name or inode; otherwise load_external_function() won't do
anything. At least on Linux, it appears that recompiling a shlib leads
to a new file with a different inode, so the old code failed to detect
a match.
pghackers. This fixes the problem recently reported by Markus KrÌutner
(hash bucket split corrupts the state of scans being done concurrently),
and I believe it also fixes all the known problems with deadlocks in
hash index operations. Hash indexes are still not really ready for prime
time (since they aren't WAL-logged), but this is a step forward.
killed items; just skip to the next item immediately. Only check for
key equality when we reach a non-killed item or the end of the index
page. This saves key comparisons when there are lots of killed items,
as for example in a heavily-updated table that's not been vacuumed lately.
Seems to be a win for pgbench anyway.
config file if it exists. This was already discussed as being a good
idea, and now seems the cleanest way to deal with initdb-time failures
on machines with small SHMMAX. (The submitted patches instead modified
initdb.sh to pass the correct sizing parameters, but that would still
leave standalone backends prone to failure later. An admin who needs
to use a standalone backend has enough trouble already, he shouldn't
have to manually configure its shmem settings...)
layout; therefore, this change forces REINDEX of hash indexes (though
not a full initdb). Widen hashm_ntuples to double so that hash space
management doesn't get confused by more than 4G entries; enlarge the
allowed number of free-space-bitmap pages; replace the useless bshift
field with a useful bmshift field; eliminate 4 bytes of wasted space
in the per-page special area.
scheme. A pleasant side effect is that it is *much* faster when deleting
a large fraction of the indexed tuples, because of elimination of
redundant hash_step activity induced by hash_adjscans. Various other
continuing code cleanup.
libpq, talking to an old server, should assume SQL_ASCII as the default
client encoding, because that is what the server will actually use (not
the server encoding).
yet). Fix a couple of bugs that would only appear if multiple bitmap pages
are used, including a buffer reference leak and incorrect computation of bit
indexes. Get rid of 'overflow address' concept, which accomplished nothing
except obfuscating the code and creating a risk of failure due to limited
range of offset field. Rename some misleadingly-named fields and routines,
and improve documentation.
explanation of the remarkably confusing page addressing scheme.
The file also includes my planned-but-not-yet-implemented revision
of the hash index locking scheme.
SQLSTATE error codes required by SQL99 (invalid format, datetime field
overflow, interval field overflow, invalid time zone displacement value).
Also emit a HINT about DateStyle in cases where it seems appropriate.
Per recent gripes.
lumping them into ERRCODE_UNDEFINED_OBJECT/ERRCODE_DUPLICATE_OBJECT.
This seems reasonable since 'object' was meant to refer to 'object in the
database' and a file is outside the database. Per request from Dave
Cramer.
max_connections at initdb time. Get rid of DEF_NBUFFERS and DEF_MAXBACKENDS
macros, which aren't doing anything useful anymore, and put more likely
defaults into postgresql.conf.sample.
perform a timestamp-to-date coercion. Instead both routines share a
subroutine that delivers the parsing result as a struct tm. This avoids
problems with timezone dependency of to_date's result, and should be
at least marginally faster too.
handling many-way scans: instead of re-evaluating all prior indexscan
quals to see if a tuple has been fetched more than once, use a hash table
indexed by tuple CTID. But fall back to the old way if the hash table
grows to exceed SortMem.
as well as the hash function (formerly the comparison function was hardwired
as memcmp()). This makes it possible to eliminate the special-purpose
hashtable management code in execGrouping.c in favor of using dynahash to
manage tuple hashtables; which is a win because dynahash knows how to expand
a hashtable when the original size estimate was too small, whereas the
special-purpose code was too stupid to do that. (See recent gripe from
Stephan Szabo about poor performance when hash table size estimate is way
off.) Free side benefit: when using string_hash, the default comparison
function is now strncmp() instead of memcmp(). This should eliminate some
part of the overhead associated with larger NAMEDATALEN values.
be anything yielding an array of the proper kind, not only sub-ARRAY[]
constructs; do subscript checking at runtime not parse time. Also,
adjust array_cat to make array || array comply with the SQL99 spec.
Joe Conway
