In particular, ensure that enlargement of the memtuples[] array doesn't
fall foul of MaxAllocSize when work_mem is very large, and don't bother
enlarging it if that would force an immediate switch into 'tape' mode anyway.
we'll go over to disk-based sort if we reach that limit.
This fixes Stefan Kaltenbrunner's observation that sorting can suffer an
'invalid memory alloc request size' failure when sort_mem is set large
enough. It's unfortunately not so easy to fix in 8.1 ...
relations are still checked for permissions etc as soon as they are
opened. The original form of the patch could hold exclusive lock for a
long time on relations that the user doesn't even have permissions to
access, let alone truncate.
checkpoint in the bgwriter. This forestalls overflow of the fsync request
queue, which is not fatal but causes considerable performance degradation
when it occurs (because backends then have to do their own fsyncs). Per
patch from Itagaki Takahiro, modified a little bit by me.
are unnecessarily allocated on the heap rather than the stack. If the
StringInfo doesn't outlive the stack frame in which it is created,
there is no need to allocate it on the heap via makeStringInfo() --
stack allocation is faster. While it's not a big deal unless the
code is in a critical path, I don't see a reason not to save a few
cycles -- using stack allocation is not less readable.
I also cleaned up a bit of code along the way: moved variable
declarations into a more tightly-enclosing scope where possible,
fixed some pointless copying of strings in dblink, etc.
more compliant with the error message style guide. In particular,
errdetail should begin with a capital letter and end with a period,
whereas errmsg should not. I also fixed a few related issues in
passing, such as fixing the repeated misspelling of "lexeme" in
contrib/tsearch2 (per Tom's suggestion).
creation of a shell type. This allows a less hacky way of dealing with
the mutual dependency between a datatype and its I/O functions: make a
shell type, then make the functions, then define the datatype fully.
We should fix pg_dump to handle things this way, but this commit just deals
with the backend.
Martijn van Oosterhout, with some corrections by Tom Lane.
bits indicating which optional capabilities can actually be exercised
at runtime. This will allow Sort and Material nodes, and perhaps later
other nodes, to avoid unnecessary overhead in common cases.
This commit just adds the infrastructure and arranges to pass the correct
flag values down to plan nodes; none of the actual optimizations are here
yet. I'm committing this separately in case anyone wants to measure the
added overhead. (It should be negligible.)
Simon Riggs and Tom Lane
each tuple, as per my proposal of several days ago. Also, clean up
sort memory management by keeping all working data in a separate memory
context, and refine the handling of low-memory conditions.
the script is not executable as UCS_to_most.pl is in CVS. It also won't
pick up any custom setting of the perl version/location to use. This
patch calls perl scripts like $(PERL) $(srcdir)/script.pl.
Kris Jurka
possible ScanDirection alternatives rather than magic numbers
(-1, 0, 1). Also, use the ScanDirection macros in a few places
rather than directly checking whether `dir == ForwardScanDirection'
and the like. Per patch from James William Pye. His patch also
changed ScanDirection to be a "char" rather than an enum, which
I haven't applied.
allocates the control data. The per-tape buffers are allocated only
on first use. This saves memory in situations where tuplesort.c
overestimates the number of tapes needed (ie, there are fewer runs
than tapes). Also, this makes legitimate the coding in inittapes()
that includes tape buffer space in the maximum-memory calculation:
when inittapes runs, we've already expended the whole allowed memory
on tuple storage, and so we'd better not allocate all the tape buffers
until we've flushed some tuples out of memory.
with fixed merge order (fixed number of "tapes") was based on obsolete
assumptions, namely that tape drives are expensive. Since our "tapes"
are really just a couple of buffers, we can have a lot of them given
adequate workspace. This allows reduction of the number of merge passes
with consequent savings of I/O during large sorts.
Simon Riggs with some rework by Tom Lane
up a bunch of the support utilities.
In src/backend/utils/mb/Unicode remove nearly duplicate copies of the
UCS_to_XXX perl script and replace with one version to handle all generic
files. Update the Makefile so that it knows about all the map files.
This produces a slight difference in some of the map files, using a
uniform naming convention and not mapping the null character.
In src/backend/utils/mb/conversion_procs create a master utf8<->win
codepage function like the ISO 8859 versions instead of having a separate
handler for each conversion.
There is an externally visible change in the name of the win1258 to utf8
conversion. According to the documentation notes, it was named
incorrectly and this changes it to a standard name.
Running the Unicode mapping perl scripts has shown some additional mapping
changes in koi8r and iso8859-7.
we are not holding a buffer content lock; where it was, InterruptHoldoffCount
is positive and so we'd not respond to cancel signals as intended. Also
add missing vacuum_delay_point() call in btvacuumcleanup. This should fix
complaint from Evgeny Gridasov about failure to respond to SIGINT/SIGTERM
in a timely fashion (bug #2257).
Var referencing the subselect output. While this case could possibly be made
to work, it seems not worth expending effort on. Per report from Magnus
Naeslund(f).
id (CVE-2006-0553). Also fix related bug in SET SESSION AUTHORIZATION that
allows unprivileged users to crash the server, if it has been compiled with
Asserts enabled. The escalation-of-privilege risk exists only in 8.1.0-8.1.2.
However, the Assert-crash risk exists in all releases back to 7.3.
Thanks to Akio Ishida for reporting this problem.
comments on cluster global objects like databases, tablespaces, and
roles.
It touches a lot of places, but not much in the way of big changes. The
only design decision I made was to duplicate the query and manipulation
functions rather than to try and have them handle both shared and local
comments. I believe this is simpler for the code and not an issue for
callers because they know what type of object they are dealing with.
This has resulted in a shobj_description function analagous to
obj_description and backend functions [Create/Delete]SharedComments
mirroring the existing [Create/Delete]Comments functions.
pg_shdescription.h goes into src/include/catalog/
Kris Jurka
during the vacuumcleanup scan that we're going to do anyway. Should
save a few cycles (one calculation per page, not per tuple) as well
as not having to depend on assumptions about heap and index being
in step.
I think this could probably be made to work for GIST too, but that
code looks messy enough that I'm disinclined to try right now.
partial. None of the existing AMs do anything useful except counting
tuples when there's nothing to delete, and we can get a tuple count
from the heap as long as it's not a partial index. (hash actually can
skip anyway because it maintains a tuple count in the index metapage.)
GIST is not currently able to exploit this optimization because, due to
failure to index NULLs, GIST is always effectively partial. Possibly
we should fix that sometime.
Simon Riggs w/ some review by Tom Lane.
