Originally, the names assigned to SLRUs had no purpose other than
being shmem lookup keys, so not a lot of thought went into them.
As of v13, though, we're exposing them in the pg_stat_slru view and
the pg_stat_reset_slru function, so it seems advisable to take a bit
more care. Rename them to names based on the associated on-disk
storage directories (which fortunately we *did* think about, to some
extent; since those are also visible to DBAs, consistency seems like
a good thing). Also rename the associated LWLocks, since those names
are likewise user-exposed now as wait event names.
For the most part I only touched symbols used in the respective modules'
SimpleLruInit() calls, not the names of other related objects. This
renaming could have been taken further, and maybe someday we will do so.
But for now it seems undesirable to change the names of any globally
visible functions or structs, so some inconsistency is unavoidable.
(But I *did* terminate "oldserxid" with prejudice, as I found that
name both unreadable and not descriptive of the SLRU's contents.)
Table 27.12 needs re-alphabetization now, but I'll leave that till
after the other LWLock renamings I have in mind.
Discussion: https://postgr.es/m/28683.1589405363@sss.pgh.pa.us
Add some more terms, clarify some definitions, remove redundant terms,
move a couple of terms to keep alphabetical order.
Co-authored-by: Jürgen Purtz <juergen@purtz.de>
Co-authored-by: Erik Rijkers <er@xs4all.nl>
Co-authored-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/7b9b469e804777ac9df4d37716db935e@xs4all.nl
COPY TO released the ACCESS SHARE lock immediately when it was done rather
than holding on to it until the end of the transaction.
This breaks the case where a REPEATABLE READ transaction could see an
empty table if it repeats a COPY statement and somebody truncated the
table in the meantime.
Before 4dded12faa the lock was also released after COPY FROM, but the
commit failed to notice the irregularity in COPY TO.
This is old behavior but doesn't seem important enough to backpatch.
Author: Laurenz Albe, based on suggestion by Robert Haas and Tom Lane
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/7bcfc39d4176faf85ab317d0c26786953646a411.camel@cybertec.at
The reasons why event triggers are disabled in standalone mode are
documented in the code path of ddl_command_start, and other places
checking if standalone mode is enabled or not mention to refer to the
comment for ddl_command_start, except for table_rewrite that duplicated
the same explanation.
Reported-by: David G. Johnston
Discussion: https://postgr.es/m/CAKFQuwYqHtXpvr2mBJRwH9f+Y5y1GXw3rhbaAu0Dk2MoNevsmA@mail.gmail.com
I abbreviated the heck out of the column headings, and made a few
small wording changes, to get it to build warning-free. I can't
say that the result is pretty, but it's probably better than
removing this table entirely.
As of this commit, we have zero "exceed the available area" warnings
in a US-letter PDF build, and one such warning (about an 863-millipoint
overrun) in an A4 build. I expect to get rid of that one by renaming
wait events, so I'm not doing anything about it at the formatting
level.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
In one or two places it seemed reasonable to modify the example so as
to shorten its output slightly; but for the most part I just added a
&zwsp; after 67 characters, which is the most we can fit on a line
of monospace text in A4 format.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.
Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
There is little point in using the LWLockRegisterTranche mechanism for
built-in tranche names. It wastes cycles, it creates opportunities for
bugs (since failing to register a tranche name is a very hard-to-detect
problem), and the lack of any centralized list of names encourages
sloppy nonconformity in name choices. Moreover, since we have a
centralized list of the tranches anyway in enum BuiltinTrancheIds, we're
certainly not buying any flexibility in return for these disadvantages.
Hence, nuke all the backend-internal LWLockRegisterTranche calls,
and instead provide a const array of the builtin tranche names.
(I have in mind to change a bunch of these names shortly, but this
patch is just about getting them into one place.)
Discussion: https://postgr.es/m/9056.1589419765@sss.pgh.pa.us
amcheck expects at least hikey to always exist on leaf page even if it is
deleted page. But replica reinitializes page during replay of page deletion,
causing deleted page to have no items. Thus, replay of page deletion can
cause an error in concurrent amcheck run.
This commit relaxes amcheck expectation making it tolerate deleted page with
no items.
Reported-by: Konstantin Knizhnik
Discussion: https://postgr.es/m/CAPpHfdt_OTyQpXaPJcWzV2N-LNeNJseNB-K_A66qG%3DL518VTFw%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Peter Geoghegan
Backpatch-through: 11
Commit 3eb77eba5a moved the loop and refactored it, and inadvertently
changed the effect of fsync=off so that it also skipped removing entries
from the pendingOps table. That was not intentional, and leads to an
assertion failure if you turn fsync on while the server is running and
reload the config.
Backpatch-through: 12-
Reviewed-By: Thomas Munro
Discussion: https://www.postgresql.org/message-id/3cbc7f4b-a5fa-56e9-9591-c886deb07513%40iki.fi
Visual Studio 2015 and later versions should still be able to do the same
as Visual Studio 2012, but the declaration of locale_name is missing in
_locale_t, causing the code compilation to fail, hence this falls back
instead on to enumerating all system locales by using EnumSystemLocalesEx
to find the required locale name. If the input argument is in Unix-style
then we can get ISO Locale name directly by using GetLocaleInfoEx() with
LCType as LOCALE_SNAME.
In passing, change the documentation references of the now obsolete links.
Note that this problem occurs only with NLS enabled builds.
Author: Juan José Santamaría Flecha, Davinder Singh and Amit Kapila
Reviewed-by: Ranier Vilela and Amit Kapila
Backpatch-through: 9.5
Discussion: https://postgr.es/m/CAHzhFSFoJEWezR96um4-rg5W6m2Rj9Ud2CNZvV4NWc9tXV7aXQ@mail.gmail.com
The defect suppressed a Standby Status Update message when bytes flushed
to disk had changed but bytes received had not changed. If
pg_recvlogical then exited with no intervening Standby Status Update,
the next pg_recvlogical repeated already-flushed records. The defect
could also cause superfluous messages, which are functionally harmless.
Back-patch to 9.5 (all supported versions).
Discussion: https://postgr.es/m/20200502221647.GA3941274@rfd.leadboat.com
pg_recvlogical merely called PQfinish(), so the backend sent messages
after the disconnect. When that caused EPIPE in internal_flush(),
before a LogicalConfirmReceivedLocation(), the next pg_recvlogical would
repeat already-acknowledged records. Whether or not the defect causes
EPIPE, post-disconnect messages could contain an ErrorResponse that the
user should see. One properly ends PGRES_COPY_OUT by repeating
PQgetCopyData() until it returns a negative value. Augment one of the
tests to cover the case of WAL past --endpos. Back-patch to v10, where
commit 7c030783a5 first appeared. Before
that commit, pg_recvlogical never reached PGRES_COPY_OUT.
Reported by Thomas Munro.
Discussion: https://postgr.es/m/CAEepm=1MzM2Z_xNe4foGwZ1a+MO_2S9oYDq3M5D11=JDU_+0Nw@mail.gmail.com
The previous design for this table didn't really work in narrow views,
such as PDF output; besides which its reliance on large morerows
values made it a pain to maintain (cf ab3e4fbd5, for example).
I experimented with a couple of ways to fix it, but the best and
simplest is to split it up into a separate table for each event
type category.
I also rearranged the event ordering to be strictly alphabetical,
as nobody would ever be able to find entries otherwise.
There is work afoot to revise the set of event names described
in this table, but this commit just changes the layout, not the
contents.
In passing, add a missing entry to pg_locks.locktype,
and cross-reference that to the related wait event list.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
This changes our catalog and view descriptions to use a style inspired
by the new format for function/operator tables: each table entry is
formatted roughly like a <varlistentry>, with the column name and type
on the first line and then an indented description. This provides much
more room for expansive descriptions than we had before, and thereby
eliminates a passel of PDF build warnings.
Discussion: https://postgr.es/m/12984.1588643549@sss.pgh.pa.us
Previously, AsyncShmemInit forcibly initialized the first page of the
async SLRU, to save dealing with that case in asyncQueueAddEntries.
But this is a poor tradeoff, since many installations do not ever use
NOTIFY; for them, expending those cycles in AsyncShmemInit is a
complete waste. Besides, this only saves a couple of instructions
in asyncQueueAddEntries, which hardly seems likely to be measurable.
The real reason to change this now, though, is that now that we track
SLRU access stats, the existing code is causing the postmaster to
accumulate some access counts, which then get inherited into child
processes by fork(), messing up the statistics. Delaying the
initialization into the first child that does a NOTIFY fixes that.
Hence, we can revert f3d23d83e, which was an incorrect attempt at
fixing that issue. Also, add an Assert to pgstat.c that should
catch any future errors of the same sort.
Discussion: https://postgr.es/m/8367.1589391884@sss.pgh.pa.us
The additional pain from level 4 is excessive for the gain.
Also revert all the source annotation changes to their original
wordings, to avoid back-patching pain.
Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
Instead of re-identifying which statistics bucket to use for a given
SLRU on every counter increment, do it once during shmem initialization.
This saves a fair number of cycles, and there's no real cost because
we could not have a bucket assignment that varies over time or across
backends anyway.
Also, get rid of the ill-considered decision to let pgstat.c pry
directly into SLRU's shared state; it's cleaner just to have slru.c
pass the stats bucket number.
In consequence of these changes, there's no longer any need to store
an SLRU's LWLock tranche info in shared memory, so get rid of that,
making this a net reduction in shmem consumption. (That partly
reverts fe702a7b3.)
This is basically code review for 28cac71bd, so I also cleaned up
some comments, removed a dangling extern declaration, fixed some
things that should be static and/or const, etc.
Discussion: https://postgr.es/m/3618.1589313035@sss.pgh.pa.us
* Have both physical and logical walsender share a 'xlogreader' state
struct for tracking state. This replaces the existing globals sendSeg
and sendCxt.
* Change WALRead not to receive XLogReaderState->seg and ->segcxt as
separate arguments anymore; just use the ones from 'state'. This is
made possible by the above change.
* have the XLogReader segment_open contract require the callbacks to
install the file descriptor in the state struct themselves instead of
returning it. xlogreader was already ignoring any possible failed
return from the callbacks, relying solely on them never returning.
(This point is not altogether excellent, as it means the callbacks
have to know more of XLogReaderState; but to really improve on that
we would have to pass back error info from the callbacks to
xlogreader. And the complexity would not be saved but instead just
transferred to the callers of WALRead, which would have to learn how
to throw errors from the open_segment callback in addition of, as
currently, from pg_pread.)
* segment_open no longer receives the 'segcxt' as a separate argument,
since it's part of the XLogReaderState argument.
Per comments from Kyotaro Horiguchi.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20200511203336.GA9913@alvherre.pgsql
This commit changes pg_stat_get_slru() so that it uses
TimestampTzGetDatum() for stats_reset field because that field
stores the timestamp with time zone value. Previously
Int64GetDatum() was used.
Author: Fujii Masao
Reviewed-by: Tomas Vondra
Discussion: https://postgr.es/m/b8784fe6-1401-ab35-aa14-d57b5bb8e312@oss.nttdata.com
Previously since SLRUStats was not initialized, SLRU stats counters
could begin with non-zero value. Which could lead to incorrect results
in pg_stat_slru view.
Author: Fujii Masao
Reviewed-by: Tomas Vondra
Discussion: https://postgr.es/m/976bbb73-a112-de3c-c488-b34b64609793@oss.nttdata.com
Use it at level 4, a bit more restrictive than the default level, and
tweak our commanding comments to FALLTHROUGH.
(However, leave zic.c alone, since it's external code; to avoid the
warnings that would appear there, change CFLAGS for that file in the
Makefile.)
Author: Julien Rouhaud <rjuju123@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol
Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
The explain format used by incremental sort was somewhat inconsistent
with other nodes, making it harder to parse and understand. This commit
addresses that by
- adding an extra space to better separate groups of values
- using colons instead of equal signs to separate key/value
- properly capitalizing first letter of a key
- using separate lines for full and pre-sorted groups
These changes were proposed by Justin Pryzby and mostly copy the final
explain format used to report WAL usage.
Author: Justin Pryzby
Reviewed-by: James Coleman
Discussion: https://postgr.es/m/20200419023625.GP26953@telsasoft.com
Run renumber_oids.pl to move high-numbered OIDs down, as per pre-beta
tasks specified by RELEASE_CHANGES. For reference, the command was
./renumber_oids.pl --first-mapped-oid=8000 --target-oid=5032
Also run reformat_dat_file.pl while I'm here.
Renumbering recently-added types changed some results in the opr_sanity
test. To make those a bit easier to eyeball-verify, change the queries
to show regtype not just bare type OIDs. (I think we didn't have
regtype when these queries were written.)
The existing callers of XLogReadDetermineTimeline() performing recovery
need to check a replay LSN position when determining on which timeline
to read a WAL page. A portion of the comment describing this function
said exactly that, while referring to a routine for fetching a write
LSN, something not available in recovery.
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20200511.101619.2043820539323292957.horikyota.ntt@gmail.com
I can't see any way to make this table fit in PDF column width
without either a fundamental redesign or abbreviating EXCLUSIVE.
So I did the latter.
It'd be nicer if the abbreviating didn't leak into the HTML output
as well; but the hackery required to make the output different
seems like more trouble than it's really worth.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
Even after the tweaking I did in commit 5545b69ae, some of the
longer keywords mentioned in the SQL standard don't fit the
available space in PDF output.
I experimented with various solutions like putting such keywords
on their own table lines, but everything looked ugly or confusing
or both; worse, the weirdness also appeared in the HTML version,
which (normally) doesn't need it.
The best answer seems to be to insert &zwsp; into long keywords
so that they can be broken into two lines when, and only when,
needed. It doesn't look too awful if the break happens after
an underscore --- and fortunately, all the problematic keywords
have underscores.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
Use xreflabel attributes instead of endterm attributes to control the
appearance of links to subsections of SQL command reference pages.
This is simpler, it matches what we do elsewhere (e.g. for GUC variables),
and it doesn't draw "Unresolved ID reference" warnings from the PDF
toolchain.
Fix some places where the text was absolutely dependent on an <xref>
rendering exactly so, by using a <link> around the required text
instead. At least one of those spots had already been turned into
bad grammar by subsequent changes, and the whole idea is just too
fragile for my taste. <xref> does NOT have fixed output, don't write
as if it does.
Consistently include a page-level link in cross-man-page references,
because otherwise they are useless/nonsensical in man-page output.
Likewise, be consistent about mentioning "below" or "above" in same-page
references; we were doing that in about 90% of the cases, but now it's
100%.
Also get rid of another nonfunctional-in-PDF idea, of making
cross-references to functions by sticking ID tags on <row> constructs.
We can put the IDs on <indexterm>s instead --- which is probably not any
more sensible in abstract terms, but it works where the other doesn't.
(There is talk of attaching cross-reference IDs to most or all of
the docs' function descriptions, but for now I just fixed the two
that exist.)
Discussion: https://postgr.es/m/14480.1589154358@sss.pgh.pa.us
Tom Lane