Commit 1a36bc9dba conained some logic that was a little opaque and
could have involved a NULL dereference, as complained about by Coverity.
Make the logic more transparent and in doing so avoid the NULL
dereference.
Getting from get_raw_page() an all-zero page is considered as a valid
case by the buffer manager and it can happen for example when finding a
corrupted page with zero_damaged_pages enabled (using zero_damaged_pages
to look at corrupted pages happens), or after a crash when a relation
file is extended before any WAL for its new data is generated (before a
vacuum or autovacuum job comes in to do some cleanup).
However, all the functions of pageinspect, as of the index AMs (except
hash that has its own idea of new pages), heap, the FSM or the page
header have never worked with all-zero pages, causing various crashes
when going through the page internals.
This commit changes all the pageinspect functions to be compliant with
all-zero pages, where the choice is made to return NULL or no rows for
SRFs when finding a new page. get_raw_page() still works the same way,
returning a batch of zeros in the bytea of the page retrieved. A hard
error could be used but NULL, while more invasive, is useful when
scanning relation files in full to get a batch of results for a single
relation in one query. Tests are added for all the code paths
impacted.
Reported-by: Daria Lepikhova
Author: Michael Paquier
Discussion: https://postgr.es/m/561e187b-3549-c8d5-03f5-525c14e65bd0@postgrespro.ru
Backpatch-through: 10
Only 1 of 3 of these changes appear to be handled by pgindent. That change
is new to v15. The remaining two appear to be left alone by pgindent. The
exact reason for that is not 100% clear to me. It seems related to the
fact that it's a line that contains *only* a single line comment and no
actual code. It does not seem worth investigating this in too much
detail. In any case, these do not conform to our usual practices, so fix
them.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
All except one of these are new to v15. Only one of the wordsmithing
changes appears in older versions. The wordsmithing improvement does not
seem significant enough to warrant backpatching.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
Input for these should be case-insensitive, but was not completely
so. Comparing to the similar queries for timezone names, I realized
that we'd missed forcing the comparison pattern to lower-case.
With that, it behaves as I expect.
While here, flatten the sub-selects in these queries; I don't
find that those add any readability.
Discussion: https://postgr.es/m/3369130.1649348542@sss.pgh.pa.us
Define "parameters with non-default settings" as being those that
not only have pg_settings.source different from 'default', but
also have a current value different from the hard-wired boot_val.
Adding the latter restriction removes a number of not-very-interesting
cases where the active setting is chosen by initdb but in practice
tends to be the same all the time.
Per discussion with Jonathan Katz.
Discussion: https://postgr.es/m/YlFQLzlPi4QD0wSi@msg.df7cb.de
heap_fetch() used to have a "keep_buf" parameter that told it to return
ownership of the buffer pin to the caller after finding that the
requested tuple TID exists but is invisible to the specified snapshot.
This was thoughtlessly removed in commit 5db6df0c0, which broke
heapam_tuple_lock() (formerly EvalPlanQualFetch) because that function
needs to do more accesses to the tuple even if it's invisible. The net
effect is that we would continue to touch the page for a microsecond or
two after releasing pin on the buffer. Usually no harm would result;
but if a different session decided to defragment the page concurrently,
we could see garbage data and mistakenly conclude that there's no newer
tuple version to chain up to. (It's hard to say whether this has
happened in the field. The bug was actually found thanks to a later
change that allowed valgrind to detect accesses to non-pinned buffers.)
The most reasonable way to fix this is to reintroduce keep_buf,
although I made it behave slightly differently: buffer ownership
is passed back only if there is a valid tuple at the requested TID.
In HEAD, we can just add the parameter back to heap_fetch().
To avoid an API break in the back branches, introduce an additional
function heap_fetch_extended() in those branches.
In HEAD there is an additional, less obvious API change: tuple->t_data
will be set to NULL in all cases where buffer ownership is not returned,
in particular when the tuple exists but fails the time qual (and
!keep_buf). This is to defend against any other callers attempting to
access non-pinned buffers. We concluded that making that change in back
branches would be more likely to introduce problems than cure any.
In passing, remove a comment about heap_fetch that was obsoleted by
9a8ee1dc6.
Per bug #17462 from Daniil Anisimov. Back-patch to v12 where the bug
was introduced.
Discussion: https://postgr.es/m/17462-9c98a0f00df9bd36@postgresql.org
There was a small buglet in commit 52e4f0cd47 whereby a tuple acquired
from cache was not released, giving rise to WARNING messages; fix that.
While at it, restructure the code a bit on stylistic grounds.
Author: Hou zj <houzj.fnst@fujitsu.com>
Reported-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAHut+PvKTyhTBtYCQsP6Ph7=o-oWRSX+v+PXXLXp81-o2bazig@mail.gmail.com
Commit f4fb45d15c misguidedly tried to free some state during aggregate
finalization for json_objectagg. This resulted in attempts to access
freed memory, especially when the function is used as a window function.
Commit 4eb9798879 attempted to ameliorate that, but in fact it should
just be ripped out, which is done here. Also add some regression tests
for json_objectagg in various flavors as a window function.
Original report from Jaime Casanova, diagnosis by Andres Freund.
Discussion: https://postgr.es/m/YkfeMNYRCGhySKyg@ahch-to
It's more accurate to say that the query identifier is not shown when
compute_query_id = regress rather than to say it is hidden.
This change (ebf6c5249) appeared in v14, so it makes sense to backpatch
this small adjustment to keep the documents consistent between v14 and
master.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
Backpatch-through: 14, where compute_query_id = regress was added
The last usage of this argument in this routine can be tracked down to
7e2f9062, aka 11 years ago. Getting rid of this argument can also be an
advantage for extensions calling check_index_is_clusterable(), as it
removes any need to worry about the meaning of what a recheck would be
at this level.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411140609.GF26620@telsasoft.com
This tries to bring a bit more consistency to the use of the <productname>
tag in the documents. This fixes a couple of mistakes with our own
product. We definitely should be consistently calling that PostgreSQL
when we're referring to the modern-day version of the software.
This also tidies up a couple of inconsistencies with the case of other
product names, namely Emacs and Python. We also get rid of some incorrect
usages of <productname> and replace them with <literal>.
Many of these mistakes exist in the back branches, but they don't quite
seem critical enough to warrant fixing them in prior versions at this
stage.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
Since babbbb5 and the introduction of LZ4 in pg_receivewal, the
compression of the WAL archived is controlled by two options:
- --compression-method with "gzip", "none" or "lz4" as possible value.
- --compress=N to specify a compression level. This includes a
backward-incompatible change where a value of 0 leads to a failure
instead of no compression enforced.
This commit takes advantage of a4b5754 and 3603f7c to rework the
compression options of pg_receivewal, as of:
- The removal of --compression-method.
- The extenction of --compress to use the same grammar as pg_basebackup,
with a METHOD:DETAIL format, where a METHOD is "gzip", "none" or "lz4"
and a DETAIL is a comma-separated list of options, the only keyword
supported is now "level" to control the compression level. If only an
integer is specified as value of this option, "none" is implied on 0
and "gzip" is implied otherwise. This brings back --compress to be
backward-compatible with ~14, while still supporting LZ4.
This has also the advantage of centralizing the set of checks used by
pg_receivewal to validate its compression options.
Author: Michael Paquier
Reviewed-by: Robert Haas, Georgios Kokolatos
Discussion: https://postgr.es/m/YlPQGNAAa04raObK@paquier.xyz
Google seems to like to return textsearch.html for queries about
GIN and GiST indexes, even though it's not a primary reference
for either. It seems likely that that's because those keywords
appear in the page title. Since "GIN and GiST Index Types" is
not a very apposite title for this material anyway, rename the
section in hopes of stopping that.
Also provide explicit links to the GIN and GiST chapters, to help
anyone who finds their way to this page regardless.
Per gripe from Jan Piotrowski. Back-patch to supported branches.
(Unfortunately Google is likely to continue returning the 9.1
version of this page, but improving that situation is a matter
for the www team.)
Discussion: https://postgr.es/m/164978902252.1276550.9330175733459697101@wrigleys.postgresql.org
It's misleading to call the data directory the "synchronized data
directory" when discussing a crash scenario when using pg_rewind's
--no-sync option. Here we just remove the word "synchronized" to avoid
any possible confusion.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
Backpatch-through: 12, where --no-sync was added
This reverts commits 0147fc7, 4567596, aa64f23, and 5ecd018.
There is no longer agreement that introducing this function
was the right way to address the problem. The consensus now
seems to favor trying to make a correct value for MaxBackends
available to mdules executing their _PG_init() functions.
Nathan Bossart
Discussion: http://postgr.es/m/20220323045229.i23skfscdbvrsuxa@jrouhaud
Enforce __pg_log_level message filtering centrally in logging.c,
instead of relying on the calling macros to do it. This is more
reliable (e.g. it works correctly for direct calls to pg_log_generic)
and it saves a percent or so of total code size because we get rid of
so many duplicate checks of __pg_log_level.
This does mean that argument expressions in a logging macro will be
evaluated even if we end up not printing anything. That seems of
little concern for INFO and higher levels as those messages are printed
by default, and most of our frontend programs don't even offer a way to
turn them off. I left the unlikely() checks in place for DEBUG
messages, though.
Discussion: https://postgr.es/m/3993549.1649449609@sss.pgh.pa.us
Commit 3804539e4 neglected to update the documentation's claim that
random() uses a "linear congruential algorithm". In hopes of avoiding
the same mistake if someone replaces our PRNG again, just say it's a
deterministic pseudo-random number generator and leave it at that.
Anybody who really wants to know can look in the source code.
COMPATIBILITY NOTE FOR RELEASE NOTES: 3804539e4's commit message
really should have mentioned that the random() sequence after
setseed(), while still repeatable, will differ from what you got
in pre-v15 releases.
Noted by Dagfinn Ilmari Mannsåker; wording suggestion by Dean Rasheed.
Discussion: https://postgr.es/m/875ynfpiru.fsf@wibble.ilmari.org
The table was in the wrong section and using an older type of link, as
reported by Sirisha, and also using an older table layout, as I noticed
while trying to figure out how and when it might have got out of sync.
Defect in commit 5dc0418f.
Author: sirisha chamarthi <sirichamarthi22@gmail.com>
Author: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CAKrAKeVk-LRHMdyT6x_p33eF6dCorM2jed5h_eHdRdv0reSYTA@mail.gmail.com
The same structure, with the same set of elements (for none, lz4, gzip
and zstd), exists in compression.h, so let's make use of the centralized
version instead of duplicating things. Some of the variables used
previously for WalCompressionMethod are renamed to stick better with the
new structure and routine names.
WalCompressionMethod was leading to some confusion in walmethods.c, as
it was sometimes used to refer to some data unrelated to WAL.
Reported-by: Robert Haas
Author: Michael Paquier
Reviewed-by: Robert Haas, Georgios Kokolatos
Discussion: https://postgr.es/m/YlPQGNAAa04raObK@paquier.xyz
We were setting MERGE source subplan's targetlist by expanding the
individual attributes of the source relation completely, early in the
parse analysis phase. This failed to work when the condition of an
action included a whole-row reference, causing setrefs.c to error out
with
ERROR: variable not found in subplan target lists
because at that point there is nothing to resolve the whole-row
reference with. We can fix this by having preprocess_targetlist expand
the source targetlist for Vars required from the source rel by all
actions. Moreover, by using this expansion mechanism we can do away
with the targetlist expansion in transformMergeStmt, which is good
because then we no longer pull in columns that aren't needed for
anything.
Add a test case for the problem.
While at it, remove some redundant code in preprocess_targetlist():
MERGE was doing separately what is already being done for UPDATE/DELETE,
so we can just rely on the latter and remove the former. (The handling
of inherited rels was different for MERGE, but that was a no-longer-
necessary hack.)
Fix outdated, related comments for fix_join_expr also.
Author: Richard Guo <guofenglinux@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Joe Wildish <joe@lateraljoin.com>
Discussion: https://postgr.es/m/fab3b90a-914d-46a9-beb0-df011ee39ee5@www.fastmail.com
Compression option handling (level, algorithm or even workers) can be
used across several parts of the system and not only base backups.
Structures, objects and routines are renamed in consequence, to remove
the concept of base backups from this part of the code making this
change straight-forward.
pg_receivewal, that has gained support for LZ4 since babbbb5, will make
use of this infrastructure for its set of compression options, bringing
more consistency with pg_basebackup. This cleanup needs to be done
before releasing a beta of 15. pg_dump is a potential future target, as
well, and adding more compression options to it may happen in 16~.
Author: Michael Paquier
Reviewed-by: Robert Haas, Georgios Kokolatos
Discussion: https://postgr.es/m/YlPQGNAAa04raObK@paquier.xyz
All but a few existing callers assume without checking that this
function succeeds. While it probably will, that's a poor excuse for
not checking. Let's make it return void and instead throw an error
if it doesn't find the block reference. Callers that actually need
to handle the no-such-block case must now use the underlying function
XLogRecGetBlockTagExtended.
In addition to being a bit less error-prone, this should also serve
to suppress some Coverity complaints about XLogRecGetBlockRefInfo.
While at it, clean up some inconsistency about use of the
XLogRecHasBlockRef macro: make XLogRecGetBlockTagExtended use
that instead of open-coding the same condition, and avoid calling
XLogRecHasBlockRef twice in relevant code paths. (That is,
calling XLogRecHasBlockRef followed by XLogRecGetBlockTag is now
deprecated: use XLogRecGetBlockTagExtended instead.)
Patch HEAD only; this doesn't seem to have enough value to consider
a back-branch API break.
Discussion: https://postgr.es/m/425039.1649701221@sss.pgh.pa.us
Remove comment block about how heap page vacuuming used to set tuples
with storage to LP_UNUSED in a rare edge case that can no longer happen
following commit 8523492d4e. The comments seem unnecessary now, since
it's now generally clear that heap vacuuming only applies to LP_DEAD
items from VACUUM's first heap pass following more recent work from
commits 12b5ade902 and 4f8d9d1217.
As of commit 39969e2a1, no caller of do_pg_backup_start() passes NULL
for labelfile or tblspcmapfile, nor is it plausible that any would
do so in the future. Remove the code that coped with that case,
as (a) it's dead and (b) it causes Coverity to bleat about possibly
leaked storage.
While here, do some janitorial work on the function's header comment.
\dconfig without an argument originally printed all parameters,
but it seems more useful to print only those parameters with
non-default settings. You can easily get the show-everything
behavior with "\dconfig *", but that output is unwieldy and
seems unlikely to be wanted very often.
Per suggestion from Christoph Berg.
Discussion: https://postgr.es/m/YlFQLzlPi4QD0wSi@msg.df7cb.de
With nowait passed as false, pgstat_lock_entry() must return true
so there's no need to check its result. Coverity seems unconvinced
of this, so whack it upside the head with a (void) cast.
The existing coding resulted in touching every copyright-containing
file in the tree, even if it was already up to date. That doesn't
matter much for the annual run, but it's an annoyance if you try
to use the script for mop-up at the close of a devel cycle, as
I just did.
Discussion: https://postgr.es/m/266030.1649685473@sss.pgh.pa.us
The documentation of REINDEX has never mentioned that the query planner
may take an ACCESS SHARE lock on the indexes depending on the query
used. This adds also a note about prepared queries not impacted when
they do not use the index(es) rebuilt.
Author: Frédéric Yhuel
Reviewed-by: Guillaume Lelarge, Justin Pryzby
Discussion: https://postgr.es/m/65d08718-6f11-978a-4b5a-72b807d4c663@dalibo.com
This is mostly driven by trying to get rid of line-too-wide
warnings in PDF output; but I think converting to a <variablelist>
makes it more readable anyway.
Discussion: https://postgr.es/m/4183048.1649536705@sss.pgh.pa.us
Commit 4a7e964fc6 made pgperlsyncheck fail, but apparently nobody
noticed, although the buildfarm module that does more or less the same
thing was modified. So fix the in-core test. I will look at unifying the
two sets of tests so we avoid a future mismatch.
Andrew Dunstan
Michael Paquier
David Rowley
Tom Lane
Alvaro Herrera
Peter Eisentraut
Robert Haas
Thomas Munro
Amit Kapila
Peter Geoghegan
Jeff Davis
Daniel Gustafsson