190 Commits

Author SHA1 Message Date
Melanie Plageman
54a3615f15 Remove misleading read stream asserts in a few users
Several read stream users asserted that the read stream was exhausted
after looping on that very condition. It was pointed out in an a
review of an as-of-yet uncommitted read stream user [1] that this was
confusing and could lead the reader to think there was a possibility of
some kind of race condition. Remove these asserts.

[1] https://postgr.es/m/F9ACE8D0-B807-4A17-B6BD-87EF0717983D%40yesql.se
2025-04-03 18:22:37 -04:00
Andres Freund
ae3df4b341 read_stream: Introduce and use optional batchmode support
Submitting IO in larger batches can be more efficient than doing so
one-by-one, particularly for many small reads. It does, however, require
the ReadStreamBlockNumberCB callback to abide by the restrictions of AIO
batching (c.f. pgaio_enter_batchmode()). Basically, the callback may not:
a) block without first calling pgaio_submit_staged(), unless a
   to-be-waited-on lock cannot be part of a deadlock, e.g. because it is
   never held while waiting for IO.

b) directly or indirectly start another batch pgaio_enter_batchmode()

As this requires care and is nontrivial in some cases, batching is only
used with explicit opt-in.

This patch adds an explicit flag (READ_STREAM_USE_BATCHING) to read_stream and
uses it where appropriate.

There are two cases where batching would likely be beneficial, but where we
aren't using it yet:

1) bitmap heap scans, because the callback reads the VM

   This should soon be solved, because we are planning to remove the use of
   the VM, due to that not being sound.

2) The first phase of heap vacuum

   This could be made to support batchmode, but would require some care.

Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
2025-03-30 18:36:41 -04:00
Tomas Vondra
49b82522f1 Remove incidental md5() function use from test
Replace md5() with sha256() in tests introduced in 14ffaece0fb5, to
allow test to pass in OpenSSL FIPS mode.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3518736.1743307492@sss.pgh.pa.us
2025-03-30 13:22:39 +02:00
Tomas Vondra
68f97aeadb amcheck: Add a GIN index to the CREATE INDEX CONCURRENTLY tests
The existing CREATE INDEX CONCURRENTLY tests checking only B-Tree, but
can be cheaply extended to also check GIN. This helps increasing test
coverage for GIN amcheck, especially related to handling concurrent page
splits and posting list trees.

This already helped to identify several issues during development of the
GIN amcheck support.

Author: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-By: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-By: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/BC221A56-977C-418E-A1B8-9EFC881D80C5%40enterprisedb.com
2025-03-29 16:47:44 +01:00
Tomas Vondra
ca738bdc4c amcheck: Add a test with GIN index on JSONB data
Extend the existing test of GIN checks to also include an index on JSONB
data, using the jsonb_path_ops opclass. This is a common enough usage of
GIN that it makes sense to have better test coverage for it.

Author: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-By: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-By: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/BC221A56-977C-418E-A1B8-9EFC881D80C5%40enterprisedb.com
2025-03-29 16:47:44 +01:00
Tomas Vondra
ec4327d106 amcheck: Fix indentation in verify_gin.c
I forgot to reindent the code after a couple last-minute adjustments
just before committing 14ffaece0fb53fed8ddbc46d2b353e1c4834863a.

Discussion: https://postgr.es/m/45AC9B0A-2B45-40EE-B08F-BDCF5739D1E1%40yandex-team.ru
2025-03-29 16:47:44 +01:00
Tomas Vondra
14ffaece0f amcheck: Add gin_index_check() to verify GIN index
Adds a new function, validating two kinds of invariants on a GIN index:

- parent-child consistency: Paths in a GIN graph have to contain
  consistent keys. Tuples on parent pages consistently include tuples
  from child pages; parent tuples do not require any adjustments.

- balanced-tree / graph: Each internal page has at least one downlink,
  and can reference either only leaf pages or only internal pages.

The GIN verification is based on work by Grigory Kryachko, reworked by
Heikki Linnakangas and with various improvements by Andrey Borodin.
Investigation and fixes for multiple bugs by Kirill Reshke.

Author: Grigory Kryachko <GSKryachko@gmail.com>
Author: Heikki Linnakangas <hlinnaka@iki.fi>
Author: Andrey Borodin <amborodin@acm.org>
Reviewed-By: José Villanova <jose.arthur@gmail.com>
Reviewed-By: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-By: Nikolay Samokhvalov <samokhvalov@gmail.com>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-By: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-By: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/45AC9B0A-2B45-40EE-B08F-BDCF5739D1E1%40yandex-team.ru
2025-03-29 15:44:29 +01:00
Tomas Vondra
d70b17636d amcheck: Move common routines into a separate module
Before performing checks on an index, we need to take some safety
measures that apply to all index AMs. This includes:

* verifying that the index can be checked - Only selected AMs are
supported by amcheck (right now only B-Tree). The index has to be
valid and not a temporary index from another session.

* changing (and then restoring) user's security context

* obtaining proper locks on the index (and table, if needed)

* discarding GUC changes from the index functions

Until now this was implemented in the B-Tree amcheck module, but it's
something every AM will have to do. So relocate the code into a new
module verify_common for reuse.

The shared steps are implemented by amcheck_lock_relation_and_check(),
receiving the AM-specific verification as a callback. Custom parameters
may be supplied using a pointer.

Author: Andrey Borodin <amborodin@acm.org>
Reviewed-By: José Villanova <jose.arthur@gmail.com>
Reviewed-By: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-By: Nikolay Samokhvalov <samokhvalov@gmail.com>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Tomas Vondra <tomas@vondra.me>
Reviewed-By: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/45AC9B0A-2B45-40EE-B08F-BDCF5739D1E1%40yandex-team.ru
2025-03-29 15:14:49 +01:00
Melanie Plageman
043799fa08 Use streaming read I/O in heap amcheck
Instead of directly invoking ReadBuffer() for each unskippable block in
the heap relation, verify_heapam() now uses the read stream API to
acquire the next buffer to check for corruption.

Author: Matheus Alcantara <matheusssilv97@gmail.com>
Co-authored-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/flat/CAFY6G8eLyz7%2BsccegZYFj%3D5tAUR-GZ9uEq4Ch5gvwKqUwb_hCA%40mail.gmail.com
2025-03-27 14:04:14 -04:00
Tom Lane
55527368bd Use PG_MODULE_MAGIC_EXT in our installable shared libraries.
It seems potentially useful to label our shared libraries with version
information, now that a facility exists for retrieving that.  This
patch labels them with the PG_VERSION string.  There was some
discussion about using semantic versioning conventions, but that
doesn't seem terribly helpful for modules with no SQL-level presence;
and for those that do have SQL objects, we typically expect them
to support multiple revisions of the SQL definitions, so it'd still
not be very helpful.

I did not label any of src/test/modules/.  It seems unnecessary since
we don't install those, and besides there ought to be someplace that
still provides test coverage for the original PG_MODULE_MAGIC macro.

Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com
2025-03-26 11:11:02 -04:00
Peter Geoghegan
426ea61117 nbtree: Make BTMaxItemSize into object-like macro.
Make nbtree's "1/3 of a page limit" BTMaxItemSize function-like macro
(which accepts a "page" argument) into an object-like macro that can be
used from code that doesn't have convenient access to an nbtree page.

Preparation for an upcoming patch that adds skip scan to nbtree.
Parallel index scans that use skip scan will serialize datums (not just
SAOP array subscripts) when scheduling primitive scans.  BTMaxItemSize
will be used by btestimateparallelscan to determine how much DSM to
request.

Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-Wz=H_RG5weNGeUG_TkK87tRBnH9mGCQj6WpM4V4FNWKv2g@mail.gmail.com
2025-03-11 10:35:56 -04:00
John Naylor
128897b101 Fix grammatical typos around possessive "its"
Some places spelled it "it's", which is short for "it is".
In passing, fix a couple other nearby grammatical errors.

Author: Jacob Brazeal <jacob.brazeal@gmail.com>
Discussion: https://postgr.es/m/CA+COZaAO8g1KJCV0T48=CkJMjAnnfTGLWOATz+2aCh40c2Nm+g@mail.gmail.com
2025-01-29 14:39:14 +07:00
Noah Misch
81772a495e Merge copies of converting an XID to a FullTransactionId.
Assume twophase.c is the performance-sensitive caller, and preserve its
choice of unlikely() branch hint.  Add some retrospective rationale for
that choice.  Back-patch to v17, for the next commit to use it.

Reviewed (in earlier versions) by Michael Paquier.

Discussion: https://postgr.es/m/17821-dd8c334263399284@postgresql.org
Discussion: https://postgr.es/m/20250116010051.f3.nmisch@google.com
2025-01-25 11:28:14 -08:00
Bruce Momjian
50e6eb731d Update copyright for 2025
Backpatch-through: 13
2025-01-01 11:21:55 -05:00
David Rowley
db448ce5ad Optimize alignment calculations in tuple form/deform
Here we convert CompactAttribute.attalign from a char, which is directly
derived from pg_attribute.attalign into a uint8, which stores the number
of bytes to align the column's value by in the tuple.

This allows tuple deformation and tuple size calculations to move away
from using the inefficient att_align_nominal() macro, which manually
checks each TYPALIGN_* char to translate that into the alignment bytes
for the given type.  Effectively, this commit changes those to TYPEALIGN
calls, which are branchless and only perform some simple arithmetic with
some bit-twiddling.

The removed branches were often mispredicted by CPUs, especially so in
real-world tables which often contain a mishmash of different types
with different alignment requirements.

Author: David Rowley
Reviewed-by: Andres Freund, Victor Yegorov
Discussion: https://postgr.es/m/CAApHDvrBztXP3yx=NKNmo3xwFAFhEdyPnvrDg3=M0RhDs+4vYw@mail.gmail.com
2024-12-21 09:43:26 +13:00
David Rowley
5983a4cffc Introduce CompactAttribute array in TupleDesc, take 2
The new compact_attrs array stores a few select fields from
FormData_pg_attribute in a more compact way, using only 16 bytes per
column instead of the 104 bytes that FormData_pg_attribute uses.  Using
CompactAttribute allows performance-critical operations such as tuple
deformation to be performed without looking at the FormData_pg_attribute
element in TupleDesc which means fewer cacheline accesses.

For some workloads, tuple deformation can be the most CPU intensive part
of processing the query.  Some testing with 16 columns on a table
where the first column is variable length showed around a 10% increase in
transactions per second for an OLAP type query performing aggregation on
the 16th column.  However, in certain cases, the increases were much
higher, up to ~25% on one AMD Zen4 machine.

This also makes pg_attribute.attcacheoff redundant.  A follow-on commit
will remove it, thus shrinking the FormData_pg_attribute struct by 4
bytes.

Author: David Rowley
Reviewed-by: Andres Freund, Victor Yegorov
Discussion: https://postgr.es/m/CAApHDvrBztXP3yx=NKNmo3xwFAFhEdyPnvrDg3=M0RhDs+4vYw@mail.gmail.com
2024-12-20 22:31:26 +13:00
Heikki Linnakangas
4d8275046c Remove remants of "snapshot too old"
Remove the 'whenTaken' and 'lsn' fields from SnapshotData. After the
removal of the "snapshot too old" feature, they were never set to a
non-zero value.

This largely reverts commit 3e2f3c2e423, which added the
OldestActiveSnapshot tracking, and the init_toast_snapshot()
function. That was only required for setting the 'whenTaken' and 'lsn'
fields. SnapshotToast is now a constant again, like SnapshotSelf and
SnapshotAny. I kept a thin get_toast_snapshot() wrapper around
SnapshotToast though, to check that you have a registered or active
snapshot. That's still a useful sanity check.

Reviewed-by: Nathan Bossart, Andres Freund, Tom Lane
Discussion: https://www.postgresql.org/message-id/cd4b4f8c-e63a-41c0-95f6-6e6cd9b83f6d@iki.fi
2024-12-09 18:13:03 +02:00
Peter Eisentraut
7f798aca1d Remove useless casts to (void *)
Many of them just seem to have been copied around for no real reason.
Their presence causes (small) risks of hiding actual type mismatches
or silently discarding qualifiers

Discussion: https://www.postgresql.org/message-id/flat/461ea37c-8b58-43b4-9736-52884e862820@eisentraut.org
2024-11-28 08:27:20 +01:00
Peter Eisentraut
9be4e5d293 Remove unused #include's from contrib, pl, test .c files
as determined by IWYU

Similar to commit dbbca2cf299, but for contrib, pl, and src/test/.

Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/0df1d5b1-8ca8-4f84-93be-121081bde049%40eisentraut.org
2024-10-28 08:02:17 +01:00
Peter Eisentraut
e7d0cf42b1 Allow TAP tests to force checksums off when calling init()
TAP tests can write

    $node->init(no_data_checksums => 1);

to initialize a cluster explicitly without checksums.  Currently, this
is the default, but this change allows running all tests with
checksums enabled, like

    PG_TEST_INITDB_EXTRA_OPTS=--data-checksums meson test ...

And this also prepares the tests for when we switch the default to
checksums enabled.

The pg_checksums tests need to disable checksums so it can test its
own functionality of enabling checksums.  The amcheck/pg_amcheck tests
need to disable checksums because they manually introduce corruption
that they want to detect, but with checksums enabled, the checksum
verification will fail before they even get to their work.

Author: Greg Sabino Mullane <greg@turnstep.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/CAKAnmmKwiMHik5AHmBEdf5vqzbOBbcwEPHo4-PioWeAbzwcTOQ@mail.gmail.com
2024-10-14 11:25:03 +02:00
Alexander Korotkov
cdd6ab9d1f amcheck: Optimize speed of checking for unique constraint violation
Currently, when amcheck validates a unique constraint, it visits the heap for
each index tuple.  This commit implements skipping keys, which have only one
non-dedeuplicated index tuple (quite common case for unique indexes). That
gives substantial economy on index checking time.

Reported-by: Noah Misch
Discussion: https://postgr.es/m/20240325020323.fd.nmisch%40google.com
Author: Alexander Korotkov, Pavel Borisov
2024-07-28 13:50:57 +03:00
Michael Paquier
0c1aca4614 Cleanup perl code from unused variables and routines
This commit removes unused variables and routines from some perl code
that have accumulated across the years.  This touches the following
areas:
- Wait event generation script.
- AdjustUpgrade.pm.
- TAP perl code

Author: Alexander Lakhin
Reviewed-by: Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/70b340bc-244a-589d-ef8b-d8aebb707a84@gmail.com
2024-07-02 09:47:16 +09:00
Alexander Korotkov
945ec4c4bc amcheck: Fixes for right page check during unique constraint check
* Don't forget to pfree() the right page when it's to be ignored.
 * Report error on unexpected non-leaf right page even if this page is not
   to be ignored.  This restores the logic which was unintendedly changed
   in 97e5b0026f.

Reported-by: Pavel Borisov
2024-05-26 07:14:12 +03:00
Alexander Korotkov
97e5b0026f amcheck: Report an error when the next page to a leaf is not a leaf
This is a very unlikely condition during checking a B-tree unique constraint,
meaning that the index structure is violated badly, and we shouldn't continue
checking to avoid endless loops, etc.  So it's worth immediately throwing an
error.

Reported-by: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzk%2B2116uOXdOViA27SHcr31WKPgmjsxXLBs_aTxAeThzg%40mail.gmail.com
Author: Pavel Borisov
2024-05-23 02:13:43 +03:00
Alexander Korotkov
0b5c161248 amcheck: Don't load the right sibling page into BtreeCheckState
5ae2087202 implemented a cross-page unique constraint check by loading
the right sibling to the BtreeCheckState.target variable.  This is wrong,
because bt_target_page_check() shouldn't change the target page.  Also,
BtreeCheckState.target shouldn't be changed alone without
BtreeCheckState.targetblock.

However, the above didn't cause any visible bugs for the following reasons.
1. We do a cross-page unique constraint check only for leaf index pages.
2. The only way target page get accessed after a cross-page unique constraint
   check is loading of the lowkey.
3. The only place lowkey is used is bt_child_highkey_check(), and that applies
   only to non-leafs.

The reasons above don't diminish the fact that changing BtreeCheckState.target
for a cross-page unique constraint check is wrong.  This commit changes this
check to temporarily store the right sibling to the local variable.

Reported-by: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzk%2B2116uOXdOViA27SHcr31WKPgmjsxXLBs_aTxAeThzg%40mail.gmail.com
Author: Pavel Borisov
2024-05-23 02:12:45 +03:00
Alexander Korotkov
532d94fec3 amcheck: Refactoring the storage of the last visible entry
This commit introduces a new data structure BtreeLastVisibleEntry comprising
information about the last visible heap entry with the current value of key.
Usage of this data structure allows us to avoid passing all this information
as individual function arguments.

Reported-by: Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/CAPpHfdsVbB9ToriaB1UHuOKwjKxiZmTFQcEF%3DjuzzC_nby31uA%40mail.gmail.com
Author: Pavel Borisov, Alexander Korotkov
2024-05-23 02:11:14 +03:00
David Rowley
a42fc1c903 Fix an assortment of typos
Author: Alexander Lakhin
Discussion: https://postgr.es/m/ae9f2fcb-4b24-5bb0-4240-efbbbd944ca1@gmail.com
2024-05-04 02:33:25 +12:00
Daniel Gustafsson
950d4a2cb1 Fix typos and duplicate words
This fixes various typos, duplicated words, and tiny bits of whitespace
mainly in code comments but also in docs.

Author: Daniel Gustafsson <daniel@yesql.se>
Author: Heikki Linnakangas <hlinnaka@iki.fi>
Author: Alexander Lakhin <exclusion@gmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/3F577953-A29E-4722-98AD-2DA9EFF2CBB8@yesql.se
2024-04-18 21:28:07 +02:00
Alexander Korotkov
b1fe8efdf1 amcheck: Normalize index tuples containing uncompressed varlena
It might happen that the varlena value wasn't compressed by index_form_tuple()
due to current storage parameters.  If compression is currently enabled, we
need to compress such values to match index tuple coming from the heap.

Backpatch to all supported versions.

Discussion: https://postgr.es/m/flat/7bdbe559-d61a-4ae4-a6e1-48abdf3024cc%40postgrespro.ru
Author: Andrey Borodin
Reviewed-by: Alexander Lakhin, Michael Zhilin, Jian He, Alexander Korotkov
Backpatch-through: 12
2024-03-24 00:09:24 +02:00
Alexander Korotkov
ab65dfb0fb amcheck: Support for different header sizes of short varlena datum
In the heap, tuples may contain short varlena datum with both 1B header and 4B
headers.  But the corresponding index tuple should always have such varlena's
with 1B headers.  So, for fingerprinting, we need to convert.

Backpatch to all supported versions.

Discussion: https://postgr.es/m/flat/7bdbe559-d61a-4ae4-a6e1-48abdf3024cc%40postgrespro.ru
Author: Michael Zhilin
Reviewed-by: Alexander Lakhin, Andrey Borodin, Jian He, Alexander Korotkov
Backpatch-through: 12
2024-03-24 00:09:24 +02:00
Jeff Davis
59825d1639 Fix buildfarm failures from 2af07e2f74.
Use GUC_ACTION_SAVE rather than GUC_ACTION_SET, necessary for working
with parallel query.

Now that the call requires more arguments, wrap the call in a new
function to avoid code duplication and offer a place for a comment.

Discussion: https://postgr.es/m/E1rhJpO-0027Wf-9L@gemulon.postgresql.org
2024-03-04 19:42:16 -08:00
Jeff Davis
2af07e2f74 Fix search_path to a safe value during maintenance operations.
While executing maintenance operations (ANALYZE, CLUSTER, REFRESH
MATERIALIZED VIEW, REINDEX, or VACUUM), set search_path to
'pg_catalog, pg_temp' to prevent inconsistent behavior.

Functions that are used for functional indexes, in index expressions,
or in materialized views and depend on a different search path must be
declared with CREATE FUNCTION ... SET search_path='...'.

This change was previously committed as 05e1737351, then reverted in
commit 2fcc7ee7af because it was too late in the cycle.

Preparation for the MAINTAIN privilege, which was previously reverted
due to search_path manipulation hazards.

Discussion: https://postgr.es/m/d4ccaf3658cb3c281ec88c851a09733cd9482f22.camel@j-davis.com
Discussion: https://postgr.es/m/E1q7j7Y-000z1H-Hr%40gemulon.postgresql.org
Discussion: https://postgr.es/m/e44327179e5c9015c8dda67351c04da552066017.camel%40j-davis.com
Reviewed-by: Greg Stark, Nathan Bossart, Noah Misch
2024-03-04 17:31:38 -08:00
Bruce Momjian
29275b1d17 Update copyright for 2024
Reported-by: Michael Paquier

Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz

Backpatch-through: 12
2024-01-03 20:49:05 -05:00
Peter Eisentraut
c538592959 Make all Perl warnings fatal
There are a lot of Perl scripts in the tree, mostly code generation
and TAP tests.  Occasionally, these scripts produce warnings.  These
are probably always mistakes on the developer side (true positives).
Typical examples are warnings from genbki.pl or related when you make
a mess in the catalog files during development, or warnings from tests
when they massage a config file that looks different on different
hosts, or mistakes during merges (e.g., duplicate subroutine
definitions), or just mistakes that weren't noticed because there is a
lot of output in a verbose build.

This changes all warnings into fatal errors, by replacing

    use warnings;

by

    use warnings FATAL => 'all';

in all Perl files.

Discussion: https://www.postgresql.org/message-id/flat/06f899fd-1826-05ab-42d6-adeb1fd5e200%40eisentraut.org
2023-12-29 18:20:00 +01:00
Peter Geoghegan
c9c0589fda Optimize nbtree backward scan boundary cases.
Teach _bt_binsrch (and related helper routines like _bt_search and
_bt_compare) about the initial positioning requirements of backward
scans.  Routines like _bt_binsrch already know all about "nextkey"
searches, so it seems natural to teach them about "goback"/backward
searches, too.  These concepts are closely related, and are much easier
to understand when discussed together.

Now that certain implementation details are hidden from _bt_first, it's
straightforward to add a new optimization: backward scans using the <
strategy now avoid extra leaf page accesses in certain "boundary cases".
Consider the following example, which uses the tenk1 table (and its
tenk1_hundred index) from the standard regression tests:

SELECT * FROM tenk1 WHERE hundred < 12 ORDER BY hundred DESC LIMIT 1;

Before this commit, nbtree would scan two leaf pages, even though it was
only really necessary to scan one leaf page.  We'll now descend straight
to the leaf page containing a (12, -inf) high key instead.  The scan
will locate matching non-pivot tuples with "hundred" values starting
from the value 11.  The scan won't waste a page access on the right
sibling leaf page, which cannot possibly contain any matching tuples.

You can think of the optimization added by this commit as disabling an
optimization (the _bt_compare "!pivotsearch" behavior that was added to
Postgres 12 in commit dd299df8) for a small subset of cases where it was
always counterproductive.

Equivalently, you can think of the new optimization as extending the
"pivotsearch" behavior that page deletion by VACUUM has long required
(since the aforementioned Postgres 12 commit went in) to other, similar
cases.  Obviously, this isn't strictly necessary for these new cases
(unlike VACUUM, _bt_first is prepared to move the scan to the left once
on the leaf level), but the underlying principle is the same.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wz=XPzM8HzaLPq278Vms420mVSHfgs9wi5tjFKHcapZCEw@mail.gmail.com
2023-12-08 11:05:17 -08:00
Heikki Linnakangas
b31ba5310b Rename ShmemVariableCache to TransamVariables
The old name was misleading: It's not a cache, the values kept in the
struct are the authoritative source.

Reviewed-by: Tristan Partin, Richard Guo
Discussion: https://www.postgresql.org/message-id/6537d63d-4bb5-46f8-9b5d-73a8ba4720ab@iki.fi
2023-12-08 09:47:15 +02:00
Noah Misch
6ec9e9975e amcheck: Distinguish interrupted page deletion from corruption.
This prevents false-positive reports about "the first child of leftmost
target page is not leftmost of its level", "block %u is not leftmost"
and "left link/right link pair".  They appeared if amcheck ran before
VACUUM cleaned things, after a cluster exited recovery between the
first-stage and second-stage WAL records of a deletion.  Back-patch to
v11 (all supported versions).

Reviewed by Peter Geoghegan.

Discussion: https://postgr.es/m/20231005025232.c7.nmisch@google.com
2023-10-30 14:46:05 -07:00
Alexander Korotkov
675fed4df5 Fix indentation in contrib/amcheck/verify_nbtree.c
Reported-by: Michael Paquier
Discussion: https://postgr.es/m/ZT9YoDPEQBUMrIHg%40paquier.xyz
2023-10-30 10:35:03 +02:00
Alexander Korotkov
5ae2087202 Teach contrib/amcheck to check the unique constraint violation
Add the 'checkunique' argument to bt_index_check() and bt_index_parent_check().
When the flag is specified the procedures will check the unique constraint
violation for unique indexes.  Only one heap entry for all equal keys in
the index should be visible (including posting list entries).  Report an error
otherwise.

pg_amcheck called with the --checkunique option will do the same check for all
the indexes it checks.

Author: Anastasia Lubennikova <lubennikovaav@gmail.com>
Author: Pavel Borisov <pashkin.elfe@gmail.com>
Author: Maxim Orlov <orlovmg@gmail.com>
Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://postgr.es/m/CALT9ZEHRn5xAM5boga0qnrCmPV52bScEK2QnQ1HmUZDD301JEg%40mail.gmail.com
2023-10-28 00:21:23 +03:00
Peter Eisentraut
611806cd72 Add trailing commas to enum definitions
Since C99, there can be a trailing comma after the last value in an
enum definition.  A lot of new code has been introducing this style on
the fly.  Some new patches are now taking an inconsistent approach to
this.  Some add the last comma on the fly if they add a new last
value, some are trying to preserve the existing style in each place,
some are even dropping the last comma if there was one.  We could
nudge this all in a consistent direction if we just add the trailing
commas everywhere once.

I omitted a few places where there was a fixed "last" value that will
always stay last.  I also skipped the header files of libpq and ecpg,
in case people want to use those with older compilers.  There were
also a small number of cases where the enum type wasn't used anywhere
(but the enum values were), which ended up confusing pgindent a bit,
so I left those alone.

Discussion: https://www.postgresql.org/message-id/flat/386f8c45-c8ac-4681-8add-e3b0852c1620%40eisentraut.org
2023-10-26 09:20:54 +02:00
Noah Misch
5f27b5f848 Dissociate btequalimage() from interval_ops, ending its deduplication.
Under interval_ops, some equal values are distinguishable.  One such
pair is '24:00:00' and '1 day'.  With that being so, btequalimage()
breaches the documented contract for the "equalimage" btree support
function.  This can cause incorrect results from index-only scans.
Users should REINDEX any btree indexes having interval-type columns.
After updating, pg_amcheck will report an error for almost all such
indexes.  This fix makes interval_ops simply omit the support function,
like numeric_ops does.  Back-pack to v13, where btequalimage() first
appeared.  In back branches, for the benefit of old catalog content,
btequalimage() code will return false for type "interval".  Going
forward, back-branch initdb will include the catalog change.

Reviewed by Peter Geoghegan.

Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
2023-10-14 16:33:51 -07:00
Thomas Munro
9f0602539d Remove some more "snapshot too old" vestiges.
Commit f691f5b8 removed the logic, but left behind some now-useless
Snapshot arguments to various AM-internal functions, and missed a couple
of comments.

Reported-by: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-Wznj9qSNXZ1P1uWTUD_FeaTezbUazb416EPwi4Qr_jR_6A%40mail.gmail.com
2023-09-08 17:12:12 +12:00
Noah Misch
01d56eecee Fix test of pg_stat_io for wal_level=minimal.
Back-patch to v16, which introduced the test.
2023-07-01 10:00:39 -07:00
Peter Geoghegan
d088ba5a5a nbtree: Allocate new pages in separate function.
Split nbtree's _bt_getbuf function is two: code that read locks or write
locks existing pages remains in _bt_getbuf, while code that deals with
allocating new pages is moved to a new, dedicated function called
_bt_allocbuf.  This simplifies most _bt_getbuf callers, since it is no
longer necessary for them to pass a heaprel argument.  Many of the
changes to nbtree from commit 61b313e4 can be reverted.  This minimizes
the divergence between HEAD/PostgreSQL 16 and earlier release branches.

_bt_allocbuf replaces the previous nbtree idiom of passing P_NEW to
_bt_getbuf.  There are only 3 affected call sites, all of which continue
to pass a heaprel for recovery conflict purposes.  Note that nbtree's
use of P_NEW was superficial; nbtree never actually relied on the P_NEW
code paths in bufmgr.c, so this change is strictly mechanical.

GiST already took the same approach; it has a dedicated function for
allocating new pages called gistNewBuffer().  That factor allowed commit
61b313e4 to make much more targeted changes to GiST.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/CAH2-Wz=8Z9qY58bjm_7TAHgtW6RzZ5Ke62q5emdCEy9BAzwhmg@mail.gmail.com
2023-06-10 14:08:25 -07:00
Jeff Davis
2fcc7ee7af Revert "Fix search_path to a safe value during maintenance operations."
This reverts commit 05e17373517114167d002494e004fa0aa32d1fd1.
2023-06-10 08:11:41 -07:00
Jeff Davis
05e1737351 Fix search_path to a safe value during maintenance operations.
While executing maintenance operations (ANALYZE, CLUSTER, REFRESH
MATERIALIZED VIEW, REINDEX, or VACUUM), set search_path to
'pg_catalog, pg_temp' to prevent inconsistent behavior.

Functions that are used for functional indexes, in index expressions,
or in materialized views and depend on a different search path must be
declared with CREATE FUNCTION ... SET search_path='...'.

This change addresses a security risk introduced in commit 60684dd834,
where a role with MAINTAIN privileges on a table may be able to
escalate privileges to the table owner. That commit is not yet part of
any release, so no need to backpatch.

Discussion: https://postgr.es/m/e44327179e5c9015c8dda67351c04da552066017.camel%40j-davis.com
Reviewed-by: Greg Stark
Reviewed-by: Nathan Bossart
2023-06-09 11:20:47 -07:00
Tom Lane
0245f8db36 Pre-beta mechanical code beautification.
Run pgindent, pgperltidy, and reformat-dat-files.

This set of diffs is a bit larger than typical.  We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop).  We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up.  Going
forward, that should make for fewer random-seeming changes to existing
code.

Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
2023-05-19 17:24:48 -04:00
Michael Paquier
8961cb9a03 Fix typos in comments
The changes done in this commit impact comments with no direct
user-visible changes, with fixes for incorrect function, variable or
structure names.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/e8c38840-596a-83d6-bd8d-cebc51111572@gmail.com
2023-05-02 12:23:08 +09:00
Michael Paquier
0ecb87e1fa Remove io prefix from pg_stat_io columns
a9c70b46 added the statistics view pg_stat_io which contained columns
"io_context" and "io_object".  Given that the columns are in the
pg_stat_io view, the "io" prefix is somewhat redundant, so remove it.

The code variables referring to these fields are kept unchanged so as
they can keep their context about I/O.

Bump catalog version.

Author: Melanie Plageman
Reviewed-by: Kyotaro Horiguchi, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CAAKRu_aAQoJWrvT2BYYQvJChFKra_O-5ra3jhzKJZqWsTR1CPQ@mail.gmail.com
2023-04-21 07:21:50 +09:00
David Rowley
b4dbf3e924 Fix various typos
This fixes many spelling mistakes in comments, but a few references to
invalid parameter names, function names and option names too in comments
and also some in string constants

Also, fix an #undef that was undefining the incorrect definition

Author: Alexander Lakhin
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
2023-04-18 13:23:23 +12:00