Tom Lane [Sat, 12 Apr 2008 23:14:21 +0000 (23:14 +0000)]
Create new routines systable_beginscan_ordered, systable_getnext_ordered,
systable_endscan_ordered that have API similar to systable_beginscan etc
(in particular, the passed-in scankeys have heap not index attnums),
but guarantee ordered output, unlike the existing functions. For the moment
these are just very thin wrappers around index_beginscan/index_getnext/etc.
Someday they might need to get smarter; but for now this is just a code
refactoring exercise to reduce the number of direct callers of index_getnext,
in preparation for changing that function's API.
In passing, remove index_getnext_indexitem, which has been dead code for
quite some time, and will have even less use than that in the presence
of run-time-lossy indexes.
Tom Lane [Fri, 11 Apr 2008 23:53:00 +0000 (23:53 +0000)]
A quick try at un-breaking the Cygwin build. Whether it needs the
pgwin32_safestat remains to be determined, but in any case the current
code is not tolerable.
Tom Lane [Fri, 11 Apr 2008 22:54:23 +0000 (22:54 +0000)]
Add some debug support code to try to catch future mistakes in the area of
input functions that include garbage bytes in their results. Provide a
compile-time option RANDOMIZE_ALLOCATED_MEMORY to make palloc fill returned
blocks with variable contents. This option also makes the parser perform
conversions of literal constants twice and compare the results, emitting a
WARNING if they don't match. (This is the code I used to catch the input
function bugs fixed in the previous commit.) For the moment, I've set it
to be activated automatically by --enable-cassert.
Tom Lane [Fri, 11 Apr 2008 22:52:05 +0000 (22:52 +0000)]
Fix several datatype input functions that were allowing unused bytes in their
results to contain uninitialized, unpredictable values. While this was okay
as far as the datatypes themselves were concerned, it's a problem for the
parser because occurrences of the "same" literal might not be recognized as
equal by datumIsEqual (and hence not by equal()). It seems sufficient to fix
this in the input functions since the only critical use of equal() is in the
parser's comparisons of ORDER BY and DISTINCT expressions.
Per a trouble report from Marc Cousin.
Patch all the way back. Interestingly, array_in did not have the bug before
8.2, which may explain why the issue went unnoticed for so long.
Tom Lane [Thu, 10 Apr 2008 22:25:26 +0000 (22:25 +0000)]
Replace "amgetmulti" AM functions with "amgetbitmap", in which the whole
indexscan always occurs in one call, and the results are returned in a
TIDBitmap instead of a limited-size array of TIDs. This should improve
speed a little by reducing AM entry/exit overhead, and it is necessary
infrastructure if we are ever to support bitmap indexes.
In an only slightly related change, add support for TIDBitmaps to preserve
(somewhat lossily) the knowledge that particular TIDs reported by an index
need to have their quals rechecked when the heap is visited. This facility
is not really used yet; we'll need to extend the forced-recheck feature to
plain indexscans before it's useful, and that hasn't been coded yet.
The intent is to use it to clean up 8.3's horrid @@@ kluge for text search
with weighted queries. There might be other uses in future, but that one
alone is sufficient reason.
Magnus Hagander [Thu, 10 Apr 2008 16:58:51 +0000 (16:58 +0000)]
Create wrapper pgwin32_safestat() and redefine stat() to it
on win32, because the stat() function in the runtime cannot
be trusted to always update the st_size field.
Tom Lane [Tue, 8 Apr 2008 18:20:29 +0000 (18:20 +0000)]
Fix tsvector_update_trigger() to be domain-friendly: it needs to allow all
the columns it works with to be domains over the expected type, not just
exactly the expected type. In passing, fix ts_stat() the same way.
Per report from Markus Wollny.
Implement a few changes to how shared libraries and dynamically loadable
modules are built. Foremost, it creates a solid distinction between these two
types of targets based on what had already been implemented and duplicated in
ad hoc ways before. Specifically,
- Dynamically loadable modules no longer get a soname. The numbers previously
set in the makefiles were dummy numbers anyway, and the presence of a soname
upset a few packaging tools, so it is nicer not to have one.
- The cumbersome detour taken on installation (build a libfoo.so.0.0.0 and
then override the rule to install foo.so instead) is removed.
Tom Lane [Sun, 6 Apr 2008 16:54:49 +0000 (16:54 +0000)]
Improve hash_any() to use word-wide fetches when hashing suitably aligned
data. This makes for a significant speedup at the cost that the results
now vary between little-endian and big-endian machines; which forces us
to add explicit ORDER BYs in a couple of regression tests to preserve
machine-independent comparison results. Also, force initdb by bumping
catversion, since the contents of hash indexes will change (at least on
big-endian machines).
Kenneth Marshall and Tom Lane, based on work from Bob Jenkins. This commit
does not adopt Bob's new faster mix() algorithm, however, since we still need
to convince ourselves that that doesn't degrade the quality of the hashing.
Tom Lane [Sat, 5 Apr 2008 01:58:20 +0000 (01:58 +0000)]
Defend against JOINs having more than 32K columns altogether. We cannot
currently support this because we must be able to build Vars referencing
join columns, and varattno is only 16 bits wide. Perhaps this should be
improved in future, but considering that it never came up before, I'm not
sure the problem is worth much effort. Per bug #4070 from Marcello
Ceschia.
The problem seems largely academic in 8.0 and 7.4, because they have
(different) O(N^2) performance issues with such wide joins, but
back-patch all the way anyway.
Bruce Momjian [Sat, 5 Apr 2008 01:34:06 +0000 (01:34 +0000)]
Have pg_stop_backup() wait for all archive files to be sent, rather than
returing right away. This guarantees that when pg_stop_backup()
returns, you have a valid backup.
Tom Lane [Fri, 4 Apr 2008 18:45:36 +0000 (18:45 +0000)]
Re-implement division for numeric values using the traditional "schoolbook"
algorithm. This is a good deal slower than our old roundoff-error-prone
code for long inputs, so we keep the old code for use in the transcendental
functions, where everything is approximate anyway. Also create a
user-accessible function div(numeric, numeric) to provide access to the
exact result of trunc(x/y) --- since the regular numeric / operator will
round off its result, simply computing that expression in SQL doesn't
reliably give the desired answer. This fixes bug #3387 and various related
corner cases, and improves the usefulness of PG for high-precision integer
arithmetic.
Bruce Momjian [Fri, 4 Apr 2008 16:57:21 +0000 (16:57 +0000)]
Implement current_query(), that shows the currently executing query.
At the same time remove dblink/dblink_current_query() as it is no longer
necessary
*BACKWARD COMPATIBILITY ISSUE* for dblink
Tom Lane [Thu, 3 Apr 2008 21:13:07 +0000 (21:13 +0000)]
Add a variant of the Levenshtein string-distance function that lets the user
specify the cost values to use, instead of always using 1's.
Volkan Yazici
In passing, remove fuzzystrmatch.h, which contained a bunch of stuff that had
no business being in a .h file; fold it into its only user, fuzzystrmatch.c.
Tom Lane [Thu, 3 Apr 2008 16:27:25 +0000 (16:27 +0000)]
Teach ANALYZE to distinguish dead and in-doubt tuples, which it formerly
classed all as "dead"; also get it to count DEAD item pointers as dead rows,
instead of ignoring them as before. Also improve matters so that tuples
previously inserted or deleted by our own transaction are handled nicely:
the stats collector's live-tuple and dead-tuple counts will end up correct
after our transaction ends, regardless of whether we end in commit or abort.
While there's more work that could be done to improve the counting of in-doubt
tuples in both VACUUM and ANALYZE, this commit is enough to alleviate some
known bad behaviors in 8.3; and the other stuff that's been discussed seems
like research projects anyway.
Tom Lane [Wed, 2 Apr 2008 18:31:50 +0000 (18:31 +0000)]
Revert my bad decision of about a year ago to make PortalDefineQuery
responsible for copying the query string into the new Portal. Such copying
is unnecessary in the common code path through exec_simple_query, and in
this case it can be enormously expensive because the string might contain
a large number of individual commands; we were copying the entire, long
string for each command, resulting in O(N^2) behavior for N commands.
(This is the cause of bug #4079.) A second problem with it is that
PortalDefineQuery really can't risk error, because if it elog's before
having set up the Portal, we will leak the plancache refcount that the
caller is trying to hand off to the portal. So go back to the design in
which the caller is responsible for making sure everything is copied into
the portal if necessary.
Tom Lane [Tue, 1 Apr 2008 03:09:30 +0000 (03:09 +0000)]
Add SPI-level support for executing SQL commands with one-time-use plans,
that is commands that have out-of-line parameters but the plan is prepared
assuming that the parameter values are constants. This is needed for the
plpgsql EXECUTE USING patch, but will probably have use elsewhere.
This commit includes the SPI functions and documentation, but no callers
nor regression tests. The upcoming EXECUTE USING patch will provide
regression-test coverage. I thought committing this separately made
sense since it's logically a distinct feature.
Tom Lane [Tue, 1 Apr 2008 00:48:33 +0000 (00:48 +0000)]
Fix an oversight I made in a cleanup patch over a year ago:
eval_const_expressions needs to be passed the PlannerInfo ("root") structure,
because in some cases we want it to substitute values for Param nodes.
(So "constant" is not so constant as all that ...) This mistake partially
disabled optimization of unnamed extended-Query statements in 8.3: in
particular the LIKE-to-indexscan optimization would never be applied if the
LIKE pattern was passed as a parameter, and constraint exclusion depending
on a parameter value didn't work either.
Tom Lane [Mon, 31 Mar 2008 03:34:27 +0000 (03:34 +0000)]
Fix my brain fade in TRUNCATE triggers patch: can't release relcache refcounts
while EState still contains pointers to those relations. Exposed by the
CLOBBER_CACHE_ALWAYS tests that buildfarm member jaguar is running (I knew
those cycles would pay off...)
Tom Lane [Mon, 31 Mar 2008 02:43:14 +0000 (02:43 +0000)]
Use error message wordings for permissions checks on .pgpass and SSL private
key files that are similar to the one for the postmaster's data directory
permissions check. (I chose to standardize on that one since it's the most
heavily used and presumably best-wordsmithed by now.) Also eliminate explicit
tests on file ownership in these places, since the ensuing read attempt must
fail anyway if it's wrong, and there seems no value in issuing the same error
message for distinct problems. (But I left in the explicit ownership test in
postmaster.c, since it had its own error message anyway.) Also be more
specific in the documentation's descriptions of these checks. Per a gripe
from Kevin Hunter.
Tom Lane [Mon, 31 Mar 2008 01:31:43 +0000 (01:31 +0000)]
Fix a number of places that were making file-type tests infelicitously.
The places that did, eg,
(statbuf.st_mode & S_IFMT) == S_IFDIR
were correct, but there is no good reason not to use S_ISDIR() instead,
especially when that's what the other 90% of our code does. The places
that did, eg,
(statbuf.st_mode & S_IFDIR)
were flat out *wrong* and would fail in various platform-specific ways,
eg a symlink could be mistaken for a regular file on most Unixen.
The actual impact of this is probably small, since the problem cases
seem to always involve symlinks or sockets, which are unlikely to be
found in the directories that PG code might be scanning. But it's
clearly trouble waiting to happen, so patch all the way back anyway.
(There seem to be no occurrences of the mistake in 7.4.)
Neil Conway [Sun, 30 Mar 2008 04:08:15 +0000 (04:08 +0000)]
Enable 64-bit integer datetimes by default, per previous discussion.
This requires a working 64-bit integer type. If such a type cannot
be found, "--disable-integer-datetimes" can be used to switch
back to the previous floating point-based datetime implementation.
Tom Lane [Sat, 29 Mar 2008 19:19:14 +0000 (19:19 +0000)]
Improve psql's tab completion to handle completing attribute names in cases
where the relation name was schema-qualified, for example
UPDATE foo.bar SET <tab>
Also support cases where the relation name was quoted unnecessarily,
for example
UPDATE "foo" SET <tab>
Greg Sabino Mullane, slightly simplified by myself.
Clarify documentation on PITR and warm standby on the fact that the standby
restore_command should report failure on non-existent .backup and .history
files. Tidy up some related text along the way.
Patch by Markus Bertheau, with some editing by Simon Riggs and myself.
Bruce Momjian [Fri, 28 Mar 2008 02:36:04 +0000 (02:36 +0000)]
Add:
> * Allow one transaction to see tuples using the snapshot of another
> transaction
>
> This would assist multiple backends in working together.
> http://archives.postgresql.org/pgsql-hackers/2008-01/msg00400.php
Tom Lane [Fri, 28 Mar 2008 02:00:11 +0000 (02:00 +0000)]
Department of second thoughts: the rule that ORDER BY and DISTINCT are
useless for an ungrouped-aggregate query holds regardless of whether
optimize_minmax_aggregates succeeds. So we might as well apply the
optimization in any case.
I'll leave 8.3 as it was, since this version is a tad more invasive
than my earlier patch.
Bruce Momjian [Thu, 27 Mar 2008 20:37:43 +0000 (20:37 +0000)]
Add to TODO:
>
> * Consider being smarter about memory and external files used during
> sorts
>
> http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php
> http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php
Tom Lane [Thu, 27 Mar 2008 19:06:14 +0000 (19:06 +0000)]
When we have successfully optimized a MIN or MAX aggregate into an indexscan,
the query result must be exactly one row (since we don't do this when there's
any GROUP BY). Therefore any ORDER BY or DISTINCT attached to the query is
useless and can be dropped. Aside from saving useless cycles, this protects
us against problems with matching the hacked-up tlist entries to sort clauses,
as seen in a bug report from Taiki Yamaguchi. We might need to work harder
if we ever try to optimize grouped queries with this approach, but this
solution will do for now.
Tom Lane [Thu, 27 Mar 2008 03:57:34 +0000 (03:57 +0000)]
Reduce the need for frontend programs to include "postgres.h" by refactoring
inclusions in src/include/catalog/*.h files. The main idea here is to push
function declarations for src/backend/catalog/*.c files into separate headers,
rather than sticking them into the corresponding catalog definition file as
has been done in the past. This commit only carries out that idea fully for
pg_proc, pg_type and pg_conversion, but that's enough for the moment ---
if pg_list.h ever becomes unsafe for frontend code to include, we'll need
to work a bit more.
Alvaro Herrera [Wed, 26 Mar 2008 16:20:48 +0000 (16:20 +0000)]
Separate snapshot management code from tuple visibility code, create a
snapmgmt.c file for the former. The header files have also been reorganized
in three parts: the most basic snapshot definitions are now in a new file
snapshot.h, and the also new snapmgmt.h keeps the definitions for snapmgmt.c.
tqual.h has been reduced to the bare minimum.
This patch is just a first step towards managing live snapshots within a
transaction; there is no functionality change.
Per my proposal to pgsql-patches on 20080318191940.GB27458@alvh.no-ip.org and
subsequent discussion.
Bruce Momjian [Wed, 26 Mar 2008 02:39:46 +0000 (02:39 +0000)]
Update TODO:
< o Consider invalidating the cache or keeping seperate cached
< copies when search_path changes
> o Consider keeping seperate cached copies when search_path changes
Tom Lane [Tue, 25 Mar 2008 22:42:46 +0000 (22:42 +0000)]
Simplify and standardize conversions between TEXT datums and ordinary C
strings. This patch introduces four support functions cstring_to_text,
cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and
two macros CStringGetTextDatum and TextDatumGetCString. A number of
existing macros that provided variants on these themes were removed.
Most of the places that need to make such conversions now require just one
function or macro call, in place of the multiple notational layers that used
to be needed. There are no longer any direct calls of textout or textin,
and we got most of the places that were using handmade conversions via
memcpy (there may be a few still lurking, though).
This commit doesn't make any serious effort to eliminate transient memory
leaks caused by detoasting toasted text objects before they reach
text_to_cstring. We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few
places where it was easy, but much more could be done.
Neil Conway [Tue, 25 Mar 2008 19:26:54 +0000 (19:26 +0000)]
Add a new tuplestore API function, tuplestore_putvalues(). This is
identical to tuplestore_puttuple(), except it operates on arrays of
Datums + nulls rather than a fully-formed HeapTuple. In several places
that use the tuplestore API, this means we can avoid creating a
HeapTuple altogether, saving a copy.