Repositioning the tuplestore seek pointer in window_gettupleslot() turns
out to be a very significant expense when the window frame is sizable and
the frame end can move. To fix, introduce a tuplestore function for
skipping an arbitrary number of tuples in one call, parallel to the one we
introduced for tuplesort objects in commit 8d65da1f. This reduces the cost
of window_gettupleslot() to O(1) if the tuplestore has not spilled to disk.
As in the previous commit, I didn't try to do any real optimization of
tuplestore_skiptuples for the case where the tuplestore has spilled to
disk. There is probably no practical way to get the cost to less than O(N)
anyway, but perhaps someone can think of something later.
Also fix PersistHoldablePortal() to make use of this API now that we have
it.
Based on a suggestion by Dean Rasheed, though this turns out not to look
much like his patch.
Given that ALTER TABLESPACE has moved on from just existing for
general purpose rename/owner changes, it deserves its own top-level
production in the grammar. This also cleans up the RenameStmt to
only ever be used for actual RENAMEs again- it really wasn't
appropriate to hide non-RENAME productions under there.
Noted by Alvaro.
Looks like we can end up with different plans happening on the
buildfarm, which breaks the regression tests when we include
EXPLAIN output (which is done in the regression tests for
updatable security views, to ensure that the user-defined
function isn't pushed down to a level where it could view the
rows before the security quals are applied).
This adds in ANALYZE to hopefully make the plans consistent.
The ANALYZE ends up changing the original plan too, so the
update looks bigger than it really is. The new plan looks
perfectly valid, of course.
Views which are marked as security_barrier must have their quals
applied before any user-defined quals are called, to prevent
user-defined functions from being able to see rows which the
security barrier view is intended to prevent them from seeing.
Remove the restriction on security barrier views being automatically
updatable by adding a new securityQuals list to the RTE structure
which keeps track of the quals from security barrier views at each
level, independently of the user-supplied quals. When RTEs are
later discovered which have securityQuals populated, they are turned
into subquery RTEs which are marked as security_barrier to prevent
any user-supplied quals being pushed down (modulo LEAKPROOF quals).
Dean Rasheed, reviewed by Craig Ringer, Simon Riggs, KaiGai Kohei
First installment of the promised moving-aggregate support in built-in
aggregates: count(), sum(), avg(), stddev() and variance() for
assorted datatypes, though not for float4/float8.
In passing, remove a 2001-vintage kluge in interval_accum(): interval
array elements have been properly aligned since around 2003, but
nobody remembered to take out this workaround. Also, fix a thinko
in the opr_sanity tests for moving-aggregate catalog entries.
David Rowley and Florian Pflug, reviewed by Dean Rasheed
Until now, when executing an aggregate function as a window function
within a window with moving frame start (that is, any frame start mode
except UNBOUNDED PRECEDING), we had to recalculate the aggregate from
scratch each time the frame head moved. This patch allows an aggregate
definition to include an alternate "moving aggregate" implementation
that includes an inverse transition function for removing rows from
the aggregate's running state. As long as this can be done successfully,
runtime is proportional to the total number of input rows, rather than
to the number of input rows times the average frame length.
This commit includes the core infrastructure, documentation, and regression
tests using user-defined aggregates. Follow-on commits will update some
of the built-in aggregates to use this feature.
David Rowley and Florian Pflug, reviewed by Dean Rasheed; additional
hacking by me
There were a couple of bugs here. First, if the fuzzy limit was exceeded,
the loop in entryGetItem might drop out too soon if a whole block needs to
be skipped because it's < advancePast ("continue" in a while-loop checks the
loop condition too). Secondly, the loop checked when stepping to a new page
that there is at least one offset on the page < advancePast, but we cannot
rely on that on subsequent calls of entryGetItem, because advancePast might
change in between. That caused the skipping loop to read bogus items in the
TbmIterateResult's offset array.
First item and fix by Alexander Korotkov, second bug pointed out by Fabrízio
de Royes Mello, by a small variation of Alexander's test query.
This operator class can accelerate subnet/supernet tests as well as
btree-equivalent ordered comparisons. It also handles a new network
operator inet && inet (overlaps, a/k/a "is supernet or subnet of"),
which is expected to be useful in exclusion constraints.
Ideally this opclass would be the default for GiST with inet/cidr data,
but we can't mark it that way until we figure out how to do a more or
less graceful transition from the current situation, in which the
really-completely-bogus inet/cidr opclasses in contrib/btree_gist are
marked as default. Having the opclass in core and not default is better
than not having it at all, though.
While at it, add new documentation sections to allow us to officially
document GiST/GIN/SP-GiST opclasses, something there was never a clear
place to do before. I filled these in with some simple tables listing
the existing opclasses and the operators they support, but there's
certainly scope to put more information there.
Emre Hasegeli, reviewed by Andreas Karlsson, further hacking by me
Instead of storing the ID of the dynamic shared memory control
segment in a file within the data directory, store it in the main
control segment. This avoids a number of nasty corner cases,
most seriously that doing an online backup and then using it on
the same machine (e.g. to fire up a standby) would result in the
standby clobbering all of the master's dynamic shared memory
segments.
Per complaints from Heikki Linnakangas, Fujii Masao, and Tom
Lane.
These functions won't throw an error if the object doesn't exist,
or if (for functions and operators) there's more than one matching
object.
Yugo Nagata and Nozomi Anzai, reviewed by Amit Khandekar, Marti
Raudsepp, Amit Kapila, and me.
Don't reset the rightlink of a page when replaying a page update record.
This was a leftover from pre-hot standby days, when it was not possible to
have scans concurrent with WAL replay. Resetting the right-link was not
necessary back then either, but it was done for the sake of tidiness. But
with hot standby, it's wrong, because a concurrent scan might still need it.
Backpatch all versions with hot standby, 9.0 and above.
The one existing assertion of this type has tripped a few times in the
buildfarm lately, but it's not clear whether the problem is really
originating there or whether it's leftovers from a trip through one
of the other two paths that lack a matching assertion. So add one.
Since the same bug(s) most likely exist(s) in the back-branches also,
back-patch to 9.2, where the fast-path lock mechanism was added.
This doesn't seem to be useful any more, and it's not really worth the
effort to keep updating it every time relevant dependencies or calling
signatures in the shared memory or semaphore code change.
Forgot to set the incomplete-split flag on the left page half, in redo of a
page split.
Spotted this by comparing the page contents on master and standby, after
inserting/applying each WAL record.
Infrastructure to allow
plpgsql.extra_warnings
plpgsql.extra_errors
Initial extra checks only for shadowed_variables
Marko Tiikkaja and Petr Jelinek
Reviewed by Simon Riggs and Pavel Stěhule
VALIDATE CONSTRAINT
CLUSTER ON
SET WITHOUT CLUSTER
ALTER COLUMN SET STATISTICS
ALTER COLUMN SET ()
ALTER COLUMN RESET ()
All other sub-commands use AccessExclusiveLock
Simon Riggs and Noah Misch
Reviews by Robert Haas and Andres Freund
When extracting trigrams from a regular expression for search of a GIN or
GIST trigram index, it's useful to penalize (preferentially discard)
trigrams that contain whitespace, since those are typically far more common
in the index than trigrams not containing whitespace. Of course, this
should only be a preference not a hard rule, since we might otherwise end
up with no trigrams to search for. The previous coding tended to produce
fairly inefficient trigram search sets for anchored regexp patterns, as
reported by Erik Rijkers. This patch penalizes whitespace-containing
trigrams, and also reduces the target number of extracted trigrams, since
experience suggests that the original coding tended to select too many
trigrams to search for.
Alexander Korotkov, reviewed by Tom Lane
Formerly, we set up the postmaster's signal handling only when we were
about to start launching subprocesses. This is a bad idea though, as
it means that for example a SIGINT arriving before that will kill the
postmaster instantly, perhaps leaving lockfiles, socket files, shared
memory, etc laying about. We'd rather that such a signal caused orderly
postmaster termination including releasing of those resources. A simple
fix is to move the PostmasterMain stanza that initializes signal handling
to an earlier point, before we've created any such resources. Then, an
early-arriving signal will be blocked until we're ready to deal with it
in the usual way. (The only part that really needs to be moved up is
blocking of signals, but it seems best to keep the signal handler
installation calls together with that; for one thing this ensures the
kernel won't drop any signals we wished to get. The handlers won't get
invoked in any case until we unblock signals in ServerLoop.)
Per a report from MauMau. He proposed changing the way "pg_ctl stop"
works to deal with this, but that'd just be masking one symptom not
fixing the core issue.
It's been like this since forever, so back-patch to all supported branches.
Also add a regression test for a GIN index with enough items with the same
key, so that a GIN posting tree gets created. Apparently none of the
existing GIN tests were large enough for that.
This code is new, no backpatching required.
EXEC_BACKEND builds (i.e., Windows) failed to absorb values of PGC_BACKEND
parameters if they'd been changed post-startup via the config file. This
for example prevented log_connections from working if it were turned on
post-startup. The mechanism for handling this case has always been a bit
of a kluge, and it wasn't revisited when we implemented EXEC_BACKEND.
While in a normal forking environment new backends will inherit the
postmaster's value of such settings, EXEC_BACKEND backends have to read
the settings from the CONFIG_EXEC_PARAMS file, and they were mistakenly
rejecting them. So this case has always been broken in the Windows port;
so back-patch to all supported branches.
Amit Kapila
Remarkably, this hasn't been noticed before, though it surely should
have been happening since around the fall of the Byzantine empire.
Commit 438b529604 changed path.c to depend on FRONTEND, and that exposed
the omission, per buildfarm reports.
I'm suspicious that some other subdirectories are missing this too,
but this one change is enough to make ecpg tests pass for me.
The code segment that removes the old symlink (if present) wasn't clued
into the fact that on Windows, symlinks are junction points which have
to be removed with rmdir().
Backpatch to 9.0, where the failing code was introduced.
MauMau, reviewed by Muhammad Asif Naeem and Amit Kapila
There's no really compelling reason to refuse to do these read-only,
non-server-starting options as root, and there's at least one good
reason to allow -C: pg_ctl uses -C to find out the true data directory
location when pointed at a config-only directory. On Windows, this is
done before dropping administrator privileges, which means that pg_ctl
fails for administrators if and only if a config-only layout is used.
Since the root-privilege check is done so early in startup, it's a bit
awkward to check for these switches. Make the somewhat arbitrary
decision that we'll only skip the root check if -C is the first switch.
This is not just to make the code a bit simpler: it also guarantees that
we can't misinterpret a --boot mode switch. (While AuxiliaryProcessMain
doesn't currently recognize any such switch, it might have one in the
future.) This is no particular problem for pg_ctl, and since the whole
behavior is undocumented anyhow, it's not a documentation issue either.
(--describe-config only works as the first switch anyway, so this is
no restriction for that case either.)
Back-patch to 9.2 where pg_ctl first began to use -C.
MauMau, heavily edited by me
This is needed because Windows services may get started with a different
current directory than where pg_ctl is executed. We want relative -D
paths to be interpreted relative to pg_ctl's CWD, similarly to what
happens on other platforms.
In support of this, move the backend's make_absolute_path() function
into src/port/path.c (where it probably should have been long since)
and get rid of the rather inferior version in pg_regress.
Kumar Rajeev Rastogi, reviewed by MauMau
The displayed sendtime and receipttime were always exactly equal, because
somebody forgot that timestamptz_to_str returns a static buffer (thereby
simplifying life for most callers, at the cost of complicating it for those
who need two results concurrently). Apply the same pstrdup solution used
by the other call sites with this issue. Back-patch to 9.2 where the
faulty code was introduced. Per bug #9849 from Haruka Takatsuka, though
this is not exactly his patch.
Possibly we should change timestamptz_to_str's API, but I wouldn't want
to do so in the back branches.
GetVirtualXIDsDelayingChkpt calls palloc, which isn't safe in a critical
section. I thought I covered this case with the exemption for the
checkpointer, but CreateCheckPoint is also called from the startup process.
For variadic functions (other than VARIADIC ANY), the syntaxes foo(x,y,...)
and foo(VARIADIC ARRAY[x,y,...]) should be considered equivalent, since the
former is converted to the latter at parse time. They have indeed been
equivalent, in all releases before 9.3. However, commit 75b39e790 made an
ill-considered decision to record which syntax had been used in FuncExpr
nodes, and then to make equal() test that in checking node equality ---
which caused the syntaxes to not be seen as equivalent by the planner.
This is the underlying cause of bug #9817 from Dmitry Ryabov.
It might seem that a quick fix would be to make equal() disregard
FuncExpr.funcvariadic, but the same commit made that untenable, because
the field actually *is* semantically significant for some VARIADIC ANY
functions. This patch instead adopts the approach of redefining
funcvariadic (and aggvariadic, in HEAD) as meaning that the last argument
is a variadic array, whether it got that way by parser intervention or was
supplied explicitly by the user. Therefore the value will always be true
for non-ANY variadic functions, restoring the principle of equivalence.
(However, the planner will continue to consider use of VARIADIC as a
meaningful difference for VARIADIC ANY functions, even though some such
functions might disregard it.)
In HEAD, this change lets us simplify the decompilation logic in
ruleutils.c, since the funcvariadic/aggvariadic flag tells directly whether
to print VARIADIC. However, in 9.3 we have to continue to cope with
existing stored rules/views that might contain the previous definition.
Fortunately, this just means no change in ruleutils.c, since its existing
behavior effectively ignores funcvariadic for all cases other than VARIADIC
ANY functions.
In HEAD, bump catversion to reflect the fact that FuncExpr.funcvariadic
changed meanings; this is sort of pro forma, since I don't believe any
built-in views are affected.
Unfortunately, this patch doesn't magically fix everything for affected
9.3 users. After installing 9.3.5, they might need to recreate their
rules/views/indexes containing variadic function calls in order to get
everything consistent with the new definition. As in the cited bug,
the symptom of a problem would be failure to use a nominally matching
index that has a variadic function call in its definition. We'll need
to mention this in the 9.3.5 release notes.
The advice to join to pg_prepared_xacts via the transaction column was not
updated when the transaction column was replaced by virtualtransaction.
Since it's not quite obvious how to do that join, give an explicit example.
For consistency also give an example for the adjacent case of joining to
pg_stat_activity. And link-ify the view references too, just because we
can. Per bug #9840 from Alexey Bashtanov.
Michael Paquier and Tom Lane
Tom Lane
Stephen Frost
Bruce Momjian
Heikki Linnakangas
Michael Meskes
Robert Haas
Simon Riggs