Tom Lane [Thu, 11 May 2006 19:15:36 +0000 (19:15 +0000)]
Code review for standard_conforming_strings patch. Fix it so it does not
throw warnings for 100%-SQL-standard constructs, clean up some minor
infelicities, try to un-break ecpg to the best of my ability. (It's not clear
how ecpg is going to find out the setting of standard_conforming_strings,
though.) I think pg_dump still needs work, too.
Tom Lane [Wed, 10 May 2006 23:18:39 +0000 (23:18 +0000)]
Clean up code associated with updating pg_class statistics columns
(relpages/reltuples). To do this, create formal support in heapam.c for
"overwrite" tuple updates (including xlog replay capability) and use that
instead of the ad-hoc overwrites we'd been using in VACUUM and CREATE INDEX.
Take the responsibility for updating stats during CREATE INDEX out of the
individual index AMs, and do it where it belongs, in catalog/index.c. Aside
from being more modular, this avoids having to update the same tuple twice in
some paths through CREATE INDEX. It's probably not measurably faster, but
for sure it's a lot cleaner than before.
Bruce Momjian [Mon, 8 May 2006 02:18:50 +0000 (02:18 +0000)]
Build server libpgport with all non-FRONTEND object files. This is to
fix a Win32 bug where pipe.c included a file that used FRONTEND, but it
wasn't on the server-build list.
Tom Lane [Mon, 8 May 2006 00:00:17 +0000 (00:00 +0000)]
Rewrite btree vacuuming to fold the former bulkdelete and cleanup operations
into a single mostly-physical-order scan of the index. This requires some
ticklish interlocking considerations, but should create no material
performance impact on normal index operations (at least given the
already-committed changes to make scans work a page at a time). VACUUM
itself should get significantly faster in any index that's degenerated to a
very nonlinear page order. Also, we save one pass over the index entirely,
except in the case where there were no deletions to do and so only one pass
happened anyway.
Original patch by Heikki Linnakangas, rework by Tom Lane.
Tom Lane [Sun, 7 May 2006 01:21:30 +0000 (01:21 +0000)]
Rewrite btree index scans to work a page at a time in all cases (both
btgettuple and btgetmulti). This eliminates the problem of "re-finding" the
exact stopping point, since the stopping point is effectively always a page
boundary, and index items are never moved across pre-existing page boundaries.
A small penalty is that the keys_are_unique optimization is effectively
disabled (and, therefore, is removed in this patch), causing us to apply
_bt_checkkeys() to at least one more tuple than necessary when looking up a
unique key. However, the advantages for non-unique cases seem great enough to
accept this tradeoff. Aside from simplifying and (sometimes) speeding up the
indexscan code, this will allow us to reimplement btbulkdelete as a largely
sequential scan instead of index-order traversal, thereby significantly
reducing the cost of VACUUM. Those changes will come in a separate patch.
Original patch by Heikki Linnakangas, rework by Tom Lane.
Tom Lane [Sat, 6 May 2006 15:51:07 +0000 (15:51 +0000)]
Further minor simplification of relcache startup: don't need a static
needNewCacheFile flag anymore, it can just be local in RelationCacheInitializePhase2.
Bruce Momjian [Fri, 5 May 2006 09:35:58 +0000 (09:35 +0000)]
Add/ cleanup:
< * %Disallow changing default expression of a SERIAL column?
> * %Disallow changing DEFAULT expression of a SERIAL column? 472a473,476
> * Add DEFAULT .. AS OWNER so permission checks are done as the table
> owner
>
> This would be useful for SERIAL nextval() calls and CHECK constraints.
Tom Lane [Thu, 4 May 2006 20:39:34 +0000 (20:39 +0000)]
Code review for contrib/pg_freespacemap. Add a storedpages column to
pg_freespacemap_relations --- while one could theoretically get that
number by counting rows in pg_freespacemap_pages, it's surely the hard
way to do it. Avoid expensive and inconvenient conversion to and from
text format. Minor code and docs cleanup.
Tom Lane [Thu, 4 May 2006 18:51:36 +0000 (18:51 +0000)]
Simplify relcache startup sequence. With the new design of InitPostgres
it's not necessary to have three separate calls anymore. This patch also
fixes things so we don't try to read pg_internal.init until after we've
obtained lock on the target database; which was fairly harmless, but it's
certainly cleaner this way.
Tom Lane [Thu, 4 May 2006 16:07:29 +0000 (16:07 +0000)]
Rethink the locking mechanisms used for CREATE/DROP/RENAME DATABASE.
The former approach used ExclusiveLock on pg_database, which being a
cluster-wide lock meant only one of these operations could proceed at
a time; worse, it also blocked all incoming connections in ReverifyMyDatabase.
Now that we have LockSharedObject(), we can use locks of different types
applied to databases considered as objects. This allows much more
flexible management of the interlocking: two CREATE DATABASEs need not
block each other, and need not block connections except to the template
database being used. Similarly DROP DATABASE doesn't block unrelated
operations. The locking used in flatfiles.c is also much narrower in
scope than before. Per recent proposal.
Tom Lane [Wed, 3 May 2006 22:45:26 +0000 (22:45 +0000)]
Create a syscache for pg_database-indexed-by-oid, and make use of it
in various places that were previously doing ad hoc pg_database searches.
This may speed up database-related privilege checks a little bit, but
the main motivation is to eliminate the performance reason for having
ReverifyMyDatabase do such a lot of stuff (viz, avoiding repeat scans
of pg_database during backend startup). The locking reason for having
that routine is about to go away, and it'd be good to have the option
to break it up.
Tom Lane [Wed, 3 May 2006 00:24:56 +0000 (00:24 +0000)]
Fix calculation of plan node extParams to account for the possibility that one
initPlan sets a parameter for another. This could not (I think) happen before
8.1, but it's possible now because the initPlans generated by MIN/MAX
optimization might themselves use initPlans. We attach those initPlans as
siblings of the MIN/MAX ones, not children, to avoid duplicate computation
when multiple MIN/MAX aggregates are present; so this leads to the case of an
initPlan needing the result of a sibling initPlan, which is not possible with
ordinary query nesting. Hadn't been noticed because in most contexts having
too much stuff listed in extParam is fairly harmless. Fixes "plan should not
reference subplan's variable" bug reported by Catalin Pitis.
Tom Lane [Tue, 2 May 2006 22:25:10 +0000 (22:25 +0000)]
Clean up API for ambulkdelete/amvacuumcleanup as per today's discussion.
This formulation requires every AM to provide amvacuumcleanup, unlike before,
but it's surely a whole lot cleaner. Also, add an 'amstorage' column to
pg_am so that we can get rid of hardwired knowledge in DefineOpClass().
Tom Lane [Tue, 2 May 2006 04:34:18 +0000 (04:34 +0000)]
Avoid assuming that statistics for a parent relation reflect the properties of
the union of its child relations as well. This might have been a good idea
when it was originally coded, but it's a fatally bad idea when inheritance is
being used for partitioning. It's better to have no stats at all than
completely misleading stats. Per report from Mark Liberman.
The bug arguably exists all the way back, but I've only patched HEAD and 8.1
because we weren't particularly trying to support partitioning before 8.1.
Eventually we ought to look at deriving union statistics instead of just
punting, but for now the drop kick looks good.
Tom Lane [Mon, 1 May 2006 23:22:43 +0000 (23:22 +0000)]
Provide a namespace.c function for lookup of an operator with exact
input datatypes given, and use this before trying OpernameGetCandidates.
This is faster than the old method when there's an exact match, and it
does not seem materially slower when there's not. And it definitely
makes some of the callers cleaner, because they didn't really want to
know about a list of candidates anyway. Per discussion with Atsushi Ogawa.
Tom Lane [Sun, 30 Apr 2006 21:15:33 +0000 (21:15 +0000)]
Code review for GRANT CONNECT patch. Spell the privilege as CONNECT not
CONNECTION, fix a number of places that were missed (eg pg_dump support),
avoid executing an extra search of pg_database during startup.
Tom Lane [Sun, 30 Apr 2006 18:30:40 +0000 (18:30 +0000)]
Improve the representation of FOR UPDATE/FOR SHARE so that we can
support both FOR UPDATE and FOR SHARE in one command, as well as both
NOWAIT and normal WAIT behavior. The more general code is actually
simpler and cleaner.
Tom Lane [Sat, 29 Apr 2006 20:13:07 +0000 (20:13 +0000)]
We only need to add thread.c on non-WIN32 platforms, since get_home_path
doesn't use pqGetpwuid on WIN32. Rather than try to figure out why it
won't build on WIN32, just remove it.
Tom Lane [Fri, 28 Apr 2006 20:57:49 +0000 (20:57 +0000)]
Remove the restriction originally coded into optimize_minmax_aggregates() that
MIN/MAX not be converted to use an index if the query WHERE clause contains
any volatile functions or subplans.
I had originally feared that the conversion might alter the behavior of such a
query with respect to a volatile function. Well, so it might, but only in the
sense that the function would get evaluated at a subset of the table rows
rather than all of them --- and we have never made any such guarantee anyway.
(For instance, we don't refuse to use an index for an ordinary non-aggregate
query when one of the non-indexable filter conditions contains a volatile
function.)
The prohibition against subplans was because of worry that that case wasn't
adequately tested, which it wasn't, but it turns out to be possible to make
8.1 fail anyway:
regression=# select o.ten, (select max(unique2) from tenk1 i where ten = o.ten
or ten = (select f1 from int4_tbl limit 1)) from tenk1 o;
ERROR: direct correlated subquery unsupported as initplan
This is due to bogus code in SS_make_initplan_from_plan (it's an initplan,
ergo it can't have any parParams). Having fixed that, we might as well allow
subplans as well as initplans.
Tom Lane [Fri, 28 Apr 2006 02:53:20 +0000 (02:53 +0000)]
Arrange to strip libpq.so of symbols that aren't officially supposed to
be exported on Linux and Darwin. We already did this on Windows but
that's not enough, as evidenced by the fact that libecpg had an unexpected
dependency on one such symbol. We should try to do it on more platforms.
Fix ecpg's oversight, and bump libpq's major .so version number to reflect
the unwanted but nonetheless real ABI break.
Tom Lane [Thu, 27 Apr 2006 17:52:40 +0000 (17:52 +0000)]
Generalize mcv_selectivity() to support both VAR OP CONST and CONST OP VAR
cases. This was not needed in the existing uses within selfuncs.c, but if
we're gonna export it for general use, the extra generality seems helpful.
Motivated by looking at ltree example.
> >> >> > 1) named parameters additionally to args[]
> >> >> > 2) return composite-types from plpython as dictionary
> >> >> > 3) return result-set from plpython as list, iterator or generator
Bruce Momjian [Thu, 27 Apr 2006 01:05:05 +0000 (01:05 +0000)]
plpython improvements:
1) named parameters additionally to args[]
2) return composite-types from plpython as dictionary
3) return result-set from plpython as list, iterator or generator
Bruce Momjian [Thu, 27 Apr 2006 00:36:34 +0000 (00:36 +0000)]
Remove unused function SSL_CTX_set_tmp_dh_callback() from libpq:
In the SSL code in libpq it does some processing with DH parameters:
SSL_CTX_set_tmp_dh_callback()
This function is marked as server use only[1], the client always uses
the DH parameters in the server, so all the code in the client dealing
with the DH parameters is useless. This patch removes it.
It's not clear why the code was added in the first place, it's been
there almost since the beginning[2]. At the time there was a suggestion
of merging the front-end and backend SSL code, but looking at the
changes since, that seems unlikely.
As a further example, the s_server program allows you to specify DH
params, but s_client doesn't. In the GnuTLS documentation under
gnutls_dh_params_generate2() it says[3]:
Also note that the DH parameters are only useful to servers. Since
clients use the parameters sent by the server, it's of no use to call
this in client side.
Bruce Momjian [Thu, 27 Apr 2006 00:33:46 +0000 (00:33 +0000)]
Use schema search path to find the first matching contraint name for SET
CONSTRAINT, rather than affecting all constraints in all schemas (which
is what we used to do). Also allow schema specifications.
Bruce Momjian [Thu, 27 Apr 2006 00:06:59 +0000 (00:06 +0000)]
Delay write of pg_stats file to once every five minutes, during
shutdown, or when requested by a backend:
It changes so the file is only written once every 5 minutes (changeable
of course, I just picked something) instead of once every half second.
It's still written when the stats collector shuts down, just as before.
And it is now also written on backend request. A backend requests a
rewrite by simply sending a special stats message. It operates on the
assumption that the backends aren't actually going to read the
statistics file very often, compared to how frequent it's written today.
Bruce Momjian [Wed, 26 Apr 2006 22:41:18 +0000 (22:41 +0000)]
Adjust /contrib/pg_freespace to show index free space as NULL (FSM only
tracks index pages, not free space on pages):
1/ Index free bytes set to NULL
2/ Comment added to the README briefly mentioning the index business
3/ Columns reordered more logically
4/ 'Blockid' column removed
5/ Free bytes column renamed to just 'bytes' instead of 'blockfreebytes'
Tom Lane [Wed, 26 Apr 2006 00:34:57 +0000 (00:34 +0000)]
Revise large-object access routines to avoid running with CurrentMemoryContext
set to the large object context ("fscxt"), as this is inevitably a source of
transaction-duration memory leaks. Not sure why we'd not noticed it before;
maybe people weren't touching a whole lot of LOs in the same transaction
before the 8.1 pg_dump changes. Per report from Wayne Conrad.
Backpatched as far as 8.1, but the problem doubtless goes all the way back.
I'm disinclined to spend the time to try to verify that the older branches
would still work if patched, seeing that this code was significantly modified
for 8.0 and again for 8.1, and that we don't have any trouble reports before
8.1. (Maybe the leaks were smaller before?)
Tom Lane [Tue, 25 Apr 2006 22:46:05 +0000 (22:46 +0000)]
Arrange to cache btree metapage data in the relcache entry for the index,
thereby saving a visit to the metapage in most index searches/updates.
This wouldn't actually save any I/O (since in the old regime the metapage
generally stayed in cache anyway), but it does provide a useful decrease
in bufmgr traffic in high-contention scenarios. Per my recent proposal.
Tom Lane [Tue, 25 Apr 2006 16:54:09 +0000 (16:54 +0000)]
The 8.1 planner removes WHERE quals from the plan when the quals are
implied by the predicate of a partial index being used to scan a table.
However, this optimization is unsafe in an UPDATE, DELETE, or SELECT FOR
UPDATE query, because the quals need to be rechecked by EvalPlanQual if
there's an update conflict. Per example from Jean-Samuel Reynaud.