Peter Eisentraut [Mon, 17 Mar 2008 19:44:41 +0000 (19:44 +0000)]
Enable probes to work with Mac OS X Leopard and other OSes that will
support DTrace in the future.
Switch from using DTRACE_PROBEn macros to the dynamically generated macros.
Use "dtrace -h" to create a header file that contains the dynamically
generated macros to be used in the source code instead of the DTRACE_PROBEn
macros. A dummy header file is generated for builds without DTrace support.
Bruce Momjian [Mon, 17 Mar 2008 18:22:44 +0000 (18:22 +0000)]
Add:
>
> o Allow Kerberos to disable stripping of realms so we can
> check the username@realm against multiple realms
>
> http://archives.postgresql.org/pgsql-hackers/2007-11/msg00009.php
Tom Lane [Mon, 17 Mar 2008 03:45:36 +0000 (03:45 +0000)]
Grab some low-hanging fruit in the new hash index build code.
oprofile shows that a nontrivial amount of time is being spent in
repeated calls to index_getprocinfo, which really only needs to be
called once. So do that, and inline _hash_datum2hashkey to make it
work.
Tom Lane [Mon, 17 Mar 2008 02:18:55 +0000 (02:18 +0000)]
Fix TransactionIdIsCurrentTransactionId() to use binary search instead of
linear search when checking child-transaction XIDs. This makes for an
important speedup in transactions that have large numbers of children,
as in a recent example from Craig Ringer. We can also get rid of an
ugly kluge that represented lists of TransactionIds as lists of OIDs.
Tom Lane [Sun, 16 Mar 2008 23:15:08 +0000 (23:15 +0000)]
When creating a large hash index, pre-sort the index entries by estimated
bucket number, so as to ensure locality of access to the index during the
insertion step. Without this, building an index significantly larger than
available RAM takes a very long time because of thrashing. On the other
hand, sorting is just useless overhead when the index does fit in RAM.
We choose to sort when the initial index size exceeds effective_cache_size.
This is a revised version of work by Tom Raney and Shreya Bhargava.
Alvaro Herrera [Sun, 16 Mar 2008 19:47:34 +0000 (19:47 +0000)]
Modify interactions between sinval.c and sinvaladt.c. The code that actually
deals with the queue, including locking etc, is all in sinvaladt.c. This means
that the struct definition of the queue, and the queue pointer, are now
internal "implementation details" inside sinvaladt.c.
Per my proposal dated 25-Jun-2007 and followup discussion.
Tom Lane [Sat, 15 Mar 2008 20:46:31 +0000 (20:46 +0000)]
Change hash index creation so that rather than always establishing exactly
two buckets at the start, we create a number of buckets appropriate for the
estimated size of the table. This avoids a lot of expensive bucket-split
actions during initial index build on an already-populated table.
This is one of the two core ideas of Tom Raney and Shreya Bhargava's patch
to reduce hash index build time. I'm committing it separately to make it
easier for people to test the effects of this separately from the effects
of their other core idea (pre-sorting the index entries by bucket number).
Tom Lane [Fri, 14 Mar 2008 23:49:28 +0000 (23:49 +0000)]
Fix inappropriately-timed memory context switch in autovacuum_do_vac_analyze.
This accidentally failed to fail before 8.3, because the context we were
switching back to was long-lived anyway; but it sure looks risky as can be
now. Well spotted by Pavan Deolasee.
Alvaro Herrera [Fri, 14 Mar 2008 17:25:59 +0000 (17:25 +0000)]
Fix vacuum so that autovacuum is really not cancelled when doing an emergency
job (i.e. to prevent Xid wraparound problems.) Bug reported by ITAGAKI
Takahiro in 20080314103837.63D3.52131E4D@oss.ntt.co.jp, though I didn't use his
patch.
Tom Lane [Thu, 13 Mar 2008 18:31:56 +0000 (18:31 +0000)]
Fix varstr_cmp's special case for UTF8 encoding on Windows so that strings
that are reported as "equal" by wcscoll() are checked to see if they really
are bitwise equal, and are sorted per strcmp() if not. We made this happen
a couple of years ago in the regular code path, but it unaccountably got
left out of the Windows/UTF8 case (probably brain fade on my part at the
time). As in the prior set of changes, affected users may need to reindex
indexes on textual columns.
Backpatch as far as 8.2, which is the oldest release we are still supporting
on Windows.
Tom Lane [Thu, 13 Mar 2008 18:00:32 +0000 (18:00 +0000)]
Fix heap_page_prune's problem with failing to send cache invalidation
messages if the calling transaction aborts later on. Collapsing out line
pointer redirects is a done deal as soon as we complete the page update,
so syscache *must* be notified even if the VACUUM FULL as a whole doesn't
complete. To fix, add some functionality to inval.c to allow the pending
inval messages to be sent immediately while heap_page_prune is still
running. The implementation is a bit chintzy: it will only work in the
context of VACUUM FULL. But that's all we need now, and it can always be
extended later if needed. Per my trouble report of a week ago.
Tom Lane [Wed, 12 Mar 2008 23:58:27 +0000 (23:58 +0000)]
Fix pg_plan_queries() to restore the previous setting of ActiveSnapshot
(probably NULL) before exiting. Up to now it's just left the variable as it
set it, which means that after we're done processing the current client
message, ActiveSnapshot is probably pointing at garbage (because this function
is typically run in MessageContext which will get reset). There doesn't seem
to have been any code path in which that mattered before 8.3, but now the
plancache module might try to use the stale value if the next client message
is a Bind for a prepared statement that is in need of replanning. Per report
from Alex Hunsaker.
Tom Lane [Wed, 12 Mar 2008 20:11:46 +0000 (20:11 +0000)]
Fix LISTEN/NOTIFY race condition reported by Laurent Birtz, by postponing
pg_listener modifications commanded by LISTEN and UNLISTEN until the end
of the current transaction. This allows us to hold the ExclusiveLock on
pg_listener until after commit, with no greater risk of deadlock than there
was before. Aside from fixing the race condition, this gets rid of a
truly ugly kludge that was there before, namely having to ignore
HeapTupleBeingUpdated failures during NOTIFY. There is a small potential
incompatibility, which is that if a transaction issues LISTEN or UNLISTEN
and then looks into pg_listener before committing, it won't see any resulting
row insertion or deletion, where before it would have. It seems unlikely
that anyone would be depending on that, though.
This patch also disallows LISTEN and UNLISTEN inside a prepared transaction.
That case had some pretty undesirable properties already, such as possibly
allowing pg_listener entries to be made for PIDs no longer present, so
disallowing it seems like a better idea than trying to maintain the behavior.
Bruce Momjian [Wed, 12 Mar 2008 18:33:54 +0000 (18:33 +0000)]
Add for Win32 TODO:
> o Diagnose problem where shared memory can sometimes not be
> attached by postmaster children
>
> http://archives.postgresql.org/pgsql-general/2007-08/msg01377.php
>
Bruce Momjian [Wed, 12 Mar 2008 01:48:08 +0000 (01:48 +0000)]
Add URL for:
* Improve speed with indexes
For large table adjustments during VACUUM FULL, it is faster to cluster
or reindex rather than update the index. Also, index updates can bloat
the index.
Bruce Momjian [Tue, 11 Mar 2008 22:31:02 +0000 (22:31 +0000)]
Add to pl/pgsql:
>
> o Improve logic of determining if an identifier is a a
> variable or column name
>
> http://archives.postgresql.org/pgsql-hackers/2007-07/msg00436.php
Bruce Momjian [Tue, 11 Mar 2008 20:46:20 +0000 (20:46 +0000)]
< * Consider adding buffers the BGW finds reusable to the free list
> * Consider adding buffers the background writer finds reusable to the
> free list
>
> * Consider wither increasing BM_MAX_USAGE_COUNT improves performance
>
> http://archives.postgresql.org/pgsql-hackers/2007-06/msg01007.php
Tom Lane [Tue, 11 Mar 2008 20:20:35 +0000 (20:20 +0000)]
Make TransactionIdIsInProgress check transam.c's single-item XID status cache
before it goes groveling through the ProcArray. In situations where the same
recently-committed transaction ID is checked repeatedly by tqual.c, this saves
a lot of shared-memory searches. And it's cheap enough that it shouldn't
hurt noticeably when it doesn't help.
Concept and patch by Simon, some minor tweaking and comment-cleanup by Tom.
Bruce Momjian [Tue, 11 Mar 2008 19:44:39 +0000 (19:44 +0000)]
Add:
>
> * Change memory allocation for multi-byte functions so memory is
> allocated inside conversion functions
>
> Currently we preallocate memory based on worst-case usage.
Bruce Momjian [Tue, 11 Mar 2008 19:34:12 +0000 (19:34 +0000)]
Add another URL for:
* Consider increasing the number of default statistics target, and
reduce statistics target overhead
Also consider having a larger statistics target for indexed columns
and expression indexes
<
> http://archives.postgresql.org/pgsql-general/2007-06/msg00542.php
Bruce Momjian [Tue, 11 Mar 2008 19:32:03 +0000 (19:32 +0000)]
Add URL for:
* Consider increasing the number of default statistics target, and
reduce statistics target overhead
Also consider having a larger statistics target for indexed columns
and expression indexes
> http://archives.postgresql.org/pgsql-general/2007-05/msg01228.php
>
Bruce Momjian [Tue, 11 Mar 2008 18:30:50 +0000 (18:30 +0000)]
Add:
>
> * Consider increasing the number of default statistics target, and
> reduce statistics target overhead
>
> Also consider having a larger statistics target for indexed columns
> and expression indexes
Bruce Momjian [Tue, 11 Mar 2008 15:45:05 +0000 (15:45 +0000)]
Add:
>
> * Consider adding buffers the BGW finds reusable to the free list
>
> http://archives.postgresql.org/pgsql-hackers/2007-04/msg00781.php
>
> * Automatically tune bgwriter_delay based on activity rather then using a
> fixed interval
>
> http://archives.postgresql.org/pgsql-hackers/2007-04/msg00781.php
Tom Lane [Mon, 10 Mar 2008 21:50:16 +0000 (21:50 +0000)]
Use -fwrapv in CFLAGS if we are using a version of gcc that accepts this flag.
This prevents compiler optimizations that assume overflow won't occur, which
breaks numerous overflow tests that we need to have working. It is known
that gcc 4.3 causes problems and possible that 4.1 does. Per my proposal
of some time ago and a recent report from Kris Jurka.
Backpatch as far as 8.0, which is as far as the patch conveniently goes.
7.x was pretty short of overflow tests anyway, so it may not matter there,
even assuming that anyone cares whether 7.x builds on recent gcc.
Tom Lane [Mon, 10 Mar 2008 20:06:27 +0000 (20:06 +0000)]
Provide a build-time option to store large relations as single files, rather
than dividing them into 1GB segments as has been our longtime practice. This
requires working support for large files in the operating system; at least for
the time being, it won't be the default.
Magnus Hagander [Mon, 10 Mar 2008 12:55:13 +0000 (12:55 +0000)]
Implement enum type for guc parameters, and convert a couple of existing
variables to it. More need to be converted, but I wanted to get this in
before it conflicts with too much...
Other than just centralising the text-to-int conversion for parameters,
this allows the pg_settings view to contain a list of available options
and allows an error hint to show what values are allowed.
Tom Lane [Mon, 10 Mar 2008 12:39:23 +0000 (12:39 +0000)]
Document and enforce that the usable range of setseed() arguments is
-1 to 1, not 0 to 1. The actual behavior for values within this range
does not change. Kris Jurka
Tom Lane [Mon, 10 Mar 2008 03:22:29 +0000 (03:22 +0000)]
Increase the default value of log_min_messages to WARNING, so that
NOTICE-grade messages are not logged by default. Per pgsql-hackers
discussion back on 21-Nov-2007.
Tom Lane [Mon, 10 Mar 2008 02:04:10 +0000 (02:04 +0000)]
Reduce memory consumption during VACUUM of large relations, by using
FSMPageData (6 bytes) instead of PageFreeSpaceInfo (8 or 16 bytes)
for the temporary array of page-free-space information.
Tom Lane [Mon, 10 Mar 2008 01:23:04 +0000 (01:23 +0000)]
Fix pgbench's getrand() function so that min and max have approximately
the same chance of being selected as do numbers between them. Problem
noted by Greg Stark; fix by Alexey Klyukin.
Tom Lane [Sun, 9 Mar 2008 04:56:28 +0000 (04:56 +0000)]
Remove postmaster.c's check that NBuffers is at least twice MaxBackends.
With the addition of multiple autovacuum workers, our choices were to delete
the check, document the interaction with autovacuum_max_workers, or complicate
the check to try to hide that interaction. Since this restriction has never
been adequate to ensure backends can't run out of pinnable buffers, it doesn't
really have enough excuse to live to justify the second or third choices.
Per discussion of a complaint from Andreas Kling (see also bug #3888).
This commit also removes several documentation references to this restriction,
but I'm not sure I got them all.
Tom Lane [Sun, 9 Mar 2008 00:32:09 +0000 (00:32 +0000)]
Change patternsel() so that instead of switching from a pure
pattern-examination heuristic method to purely histogram-driven selectivity at
histogram size 100, we compute both estimates and use a weighted average.
The weight put on the heuristic estimate decreases linearly with histogram
size, dropping to zero for 100 or more histogram entries.
Likewise in ltreeparentsel(). After a patch by Greg Stark, though I
reorganized the logic a bit to give the caller of histogram_selectivity()
more control.
Tom Lane [Sat, 8 Mar 2008 22:41:38 +0000 (22:41 +0000)]
Modify prefix_selectivity() so that it will never estimate the selectivity
of the generated range condition var >= 'foo' AND var < 'fop' as being less
than what eqsel() would estimate for var = 'foo'. This is intuitively
reasonable and it gets rid of the need for some entirely ad-hoc coding we
formerly used to reject bogus estimates. The basic problem here is that
if the prefix is more than a few characters long, the two boundary values
are too close together to be distinguishable by comparison to the column
histogram, resulting in a selectivity estimate of zero, which is often
not very sane. Change motivated by an example from Peter Eisentraut.
Arguably this is a bug fix, but I'll refrain from back-patching it
for the moment.
Tom Lane [Sat, 8 Mar 2008 21:57:59 +0000 (21:57 +0000)]
Refactor heap_page_prune so that instead of changing item states on-the-fly,
it accumulates the set of changes to be made and then applies them. It had
to accumulate the set of changes anyway to prepare a WAL record for the
pruning action, so this isn't an enormous change; the only new complexity is
to not doubly mark tuples that are visited twice in the scan. The main
advantage is that we can substantially reduce the scope of the critical
section in which the changes are applied, thus avoiding PANIC in foreseeable
cases like running out of memory in inval.c. A nice secondary advantage is
that it is now far clearer that WAL replay will actually do the same thing
that the original pruning did.
This commit doesn't do anything about the open problem that
CacheInvalidateHeapTuple doesn't have the right semantics for a CTID change
caused by collapsing out a redirect pointer. But whatever we do about that,
it'll be a good idea to not do it inside a critical section.
Andrew Dunstan [Sat, 8 Mar 2008 01:16:26 +0000 (01:16 +0000)]
Improve efficiency of attribute scanning in CopyReadAttributesCSV.
The loop is split into two parts, inside quotes, and outside quotes, saving some instructions in both parts.
Tom Lane [Sat, 8 Mar 2008 01:09:36 +0000 (01:09 +0000)]
Improve pglz_decompress() so that it cannot clobber memory beyond the
available output buffer when presented with corrupt input. Some testing
suggests that this slows the decompression loop about 1%, which seems an
acceptable price to pay for more robustness. (Curiously, the penalty
seems to be *less* on not-very-compressible data, which I didn't expect
since the overhead per output byte ought to be more in the literal-bytes
path.)
Patch from Zdenek Kotala. I fixed a corner case and did some renaming
of variables to make the routine more readable.
Tom Lane [Fri, 7 Mar 2008 23:20:21 +0000 (23:20 +0000)]
This patch addresses some issues in TOAST compression strategy that
were discussed last year, but we felt it was too late in the 8.3 cycle to
change the code immediately. Specifically, the patch:
* Reduces the minimum datum size to be considered for compression from
256 to 32 bytes, as suggested by Greg Stark.
* Increases the required compression rate for compressed storage from
20% to 25%, again per Greg's suggestion.
* Replaces force_input_size (size above which compression is forced)
with a maximum size to be considered for compression. It was agreed
that allowing large inputs to escape the minimum-compression-rate
requirement was not bright, and that indeed we'd rather have a knob
that acted in the other direction. I set this value to 1MB for the
moment, but it could use some performance studies to tune it.
* Adds an early-failure path to the compressor as suggested by Jan:
if it's been unable to find even one compressible substring in the
first 1KB (parameterizable), assume we're looking at incompressible
input and give up. (Possibly this logic can be improved, but I'll
commit it as-is for now.)
* Improves the toasting heuristics so that when we have very large
fields with attstorage 'x' or 'e', we will push those out to toast
storage before considering inline compression of shorter fields.
This also responds to a suggestion of Greg's, though my original
proposal for a solution was a bit off base because it didn't fix
the problem for large 'e' fields.
There was some discussion in the earlier threads of exposing some
of the compression knobs to users, perhaps even on a per-column
basis. I have not done anything about that here. It seems to me
that if we are changing around the parameters, we'd better get some
experience and be sure we are happy with the design before we set
things in stone by providing user-visible knobs.
Bruce Momjian [Fri, 7 Mar 2008 20:38:59 +0000 (20:38 +0000)]
Add:
>
> * Add a function like pg_get_indexdef() that report more detailed index
> information
>
> http://archives.postgresql.org/pgsql-bugs/2007-12/msg00166.php
>
Bruce Momjian [Fri, 7 Mar 2008 20:22:25 +0000 (20:22 +0000)]
Add:
>
>
> o Prevent autovacuum from running if an old transaction is still
> running from the last vacuum
>
> http://archives.postgresql.org/pgsql-hackers/2007-11/msg00899.php
>
projects / postgresql / log