Age | Commit message (Collapse) | Author |
|
xmltotext_with_options() did not consider the possibility that
pg_xml_init() could fail --- most likely due to OOM. If that
happened, the already-parsed xmlDoc structure would be leaked.
Oversight in commit 483bdb2af.
Bug: #18981
Author: Dmitry Kovalenko <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 16
|
|
This commit standardizes the output format for LSNs to ensure consistent
representation across various tools and messages. Previously, LSNs were
inconsistently printed as `%X/%X` in some contexts, while others used
zero-padding. This often led to confusion when comparing.
To address this, the LSN format is now uniformly set to `%X/%08X`,
ensuring the lower 32-bit part is always zero-padded to eight
hexadecimal digits.
Author: Japin Li <[email protected]>
Reviewed-by: Masahiko Sawada <[email protected]>
Reviewed-by: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/ME0P300MB0445CA53CA0E4B8C1879AF84B641A@ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
|
|
Previous commits invented timestamp2timestamptz_opt_overflow,
date2timestamp_opt_overflow, and date2timestamptz_opt_overflow
functions to perform non-error-throwing conversions between
datetime types. This patch completes the set by adding
timestamp2date_opt_overflow, timestamptz2date_opt_overflow,
and timestamptz2timestamp_opt_overflow.
In addition, adjust timestamp2timestamptz_opt_overflow so that it
doesn't throw error if timestamp2tm fails, but treats that as an
overflow case. The situation probably can't arise except with an
invalid timestamp value, and I can't think of a way that that would
happen except data corruption. However, it's pretty silly to have a
function whose entire reason for existence is to not throw errors for
out-of-range inputs nonetheless throw an error for out-of-range input.
The new APIs are not used in this patch, but will be needed in
upcoming btree_gin changes.
Author: Tom Lane <[email protected]>
Reviewed-by: Arseniy Mukhin <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
The array-based variant of width_bucket() has always accepted NaN
inputs, treating them as equal but larger than any non-NaN,
as we do in ordinary comparisons. But up to now, the four-argument
variants threw errors for a NaN operand. This is inconsistent
and unnecessary, since we can perfectly well regard NaN as falling
after the last bucket.
We do still throw error for NaN or infinity histogram-bound inputs,
since there's no way to compute sensible bucket boundaries.
Arguably this is a bug fix, but given the lack of field complaints
I'm content to fix it in master.
Author: Tom Lane <[email protected]>
Reviewed-by: Dean Rasheed <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
This commit moves all the routines related to the bytea data type into
its own new file, called bytea.c, clearing some of the bloat in
varlena.c. This includes the routines for:
- Input, output, receive and send
- Comparison
- Casts to integer types
- bytea-specific functions
The internals of the routines moved here are unchanged, with one
exception. This comes with a twist in bytea_string_agg_transfn(), where
the call to makeStringAggState() is replaced by the internals of this
routine, still located in varlena.c. This simplifies the move to the
new file by not having to expose makeStringAggState().
Author: Aleksander Alekseev <[email protected]>
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/CAJ7c6TMPVPJ5DL447zDz5ydctB8OmuviURtSwd=PHCRFEPDEAQ@mail.gmail.com
|
|
The behavior of pg_locale_t is specified by methods, so a separate
provider field is no longer necessary.
Reviewed-by: Andreas Karlsson <[email protected]>
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/2830211e1b6e6a2e26d845780b03e125281ea17b.camel%40j-davis.com
|
|
Previously, pattern matching and case mapping behavior branched based
on the provider. Refactor to use a method table, which is less
error-prone.
This is also a step toward multiple provider versions, which we may
want to support in the future.
Reviewed-by: Andreas Karlsson <[email protected]>
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/2830211e1b6e6a2e26d845780b03e125281ea17b.camel%40j-davis.com
|
|
Avoids unnecessary dependence on setlocale(). No behavior change.
This commit reverts e1458f2f1b, which reverted some changes
unintentionally committed before the branch for 19.
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]
|
|
This commit fixes some defects in the backend's xml.c, found upon
inspection of the internals of libxml2:
- xmlEncodeSpecialChars() can fail on malloc(), returning NULL back to
the caller. xmltext() assumed that this could never happen. Like other
code paths, a TRY/CATCH block is added there, covering also the fact
that cstring_to_text_with_len() could fail a memory allocation, where
the backend would miss to free the buffer allocated by
xmlEncodeSpecialChars().
- Some libxml2 routines called in xmlelement() can return NULL, like
xmlAddChildList() or xmlTextWriterStartElement(). Dedicated errors are
added for them.
- xml_xmlnodetoxmltype() missed that xmlXPathCastNodeToString() can fail
on an allocation failure. In this case, the call can just be moved to
the existing TRY/CATCH block.
All these code paths would cause the server to crash. As this is
unlikely a problem in practice, no backpatch is done. Jim and I have
caught these defects, not sure who has scored the most. The contrib
module xml2/ has similar defects, which will be addressed in a separate
change.
Reported-by: Jim Jones <[email protected]>
Reviewed-by: Jim Jones <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
This provides a convenient way to look up a database's OID. For
example, the query
SELECT * FROM pg_shdepend
WHERE dbid = (SELECT oid FROM pg_database
WHERE datname = current_database());
can now be simplified to
SELECT * FROM pg_shdepend
WHERE dbid = current_database()::regdatabase;
Like the regrole type, regdatabase has cluster-wide scope, so we
disallow regdatabase constants from appearing in stored
expressions.
Bumps catversion.
Author: Ian Lawrence Barwick <[email protected]>
Reviewed-by: Greg Sabino Mullane <[email protected]>
Reviewed-by: Jian He <[email protected]>
Reviewed-by: Fabrízio de Royes Mello <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/aBpjJhyHpM2LYcG0%40nathan
|
|
Author: Aleksander Alekseev <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/CAJ7c6TOowVbR-0NEvvDm6a_mag18krR0XJ2FKrc9DHXj7hFRtQ%40mail.gmail.com
|
|
|
|
Specify whether the bucket bounds are inclusive or exclusive,
and improve some other vague language. Explain the behavior that
occurs when the "low" bound is greater than the "high" bound.
Make width_bucket_numeric's comment more like that for
width_bucket_float8, in particular noting that infinite
bounds are rejected (since they became possible in v14).
Reported-by: Ben Peachey Higdon <[email protected]>
Author: Robert Treat <[email protected]>
Co-authored-by: Tom Lane <[email protected]>
Reviewed-by: Dean Rasheed <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 13
|
|
Our maintenance of typedefs.list has been a little haphazard
(and apparently we can't alphabetize worth a darn). Replace
the file with the authoritative list from our buildfarm, and
run pgindent using that.
I also updated the additions/exclusions lists in pgindent where
necessary to keep pgindent from messing things up significantly.
Notably, now that regex_t and some related names are macros not real
typedefs, we have to whitelist them explicitly. The exclusions list
has also drifted noticeably, presumably due to changes of system
headers on the buildfarm animals that contribute to the list.
Unlike in prior years, I've not manually added typedef names that
are missing from the buildfarm's list because they are not used to
declare any variables or fields. So there are a few places where
the typedef declaration itself is formatted worse than before,
e.g. typedef enum IoMethod. I could preserve the names that were
manually added to the list previously, but I'd really prefer to find
a less manual way of dealing with these cases. A quick grep finds
about 75 such symbols, most of which have never gotten any special
treatment.
Per discussion among pgsql-release, doing this now seems appropriate
even though we're still a week or two away from making the v18 branch.
|
|
- 4c787a24e7e220a60022e47c1776f22f72902899
- 78bd364ee39ca70a8f9cb8719282389866a08e14
- 7a6880fadc177873d5663961ec3a02d67e34dcbe
- 8898082a5d3e94eef073f0e08124137e096e78ef
Suggested-by: Robert Haas <[email protected]>
Discussion: https://postgr.es/m/CA+TgmoZ=J=PVNZUNKaxULu+KUVSt3Y-aJ1DZ9Y3Co6mu0z62jA@mail.gmail.com
Discussion: https://postgr.es/m/[email protected]
|
|
Avoid dependence on setlocale(). No behavior change.
Discussion: https://postgr.es/m/[email protected]
Reviewed-by: Peter Eisentraut <[email protected]>
|
|
|
|
uint64 was perhaps chosen in cff440d36 as the type was uint32 prior to
that widening work.
Having this as uint64 doesn't make much sense and just adds the overhead of
having to remember that we always output this in its signed form. Let's
remove that overhead.
The signed form output is seemingly required since we have no way to
represent the full range of uint64 in an SQL type. We use BIGINT in places
like pg_stat_statements, which maps directly to int64.
The release notes "Source Code" section may want to mention this
adjustment as some extensions may wish to adjust their code.
Author: David Rowley <[email protected]>
Suggested-by: Peter Eisentraut <[email protected]>
Reviewed-by: Sami Imseih <[email protected]>
Reviewed-by: Michael Paquier <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
ParseFraction only expects to deal with fields that contain a decimal
point and digit(s). However it's possible in some edge cases for it
to be passed input that doesn't look like that. In particular the
input could look like a valid floating-point number, such as ".123e6".
strtod() will happily eat that, possibly producing a result that is
not within the expected range 0..1, which can result in integer
overflow in the callers. That doesn't have any security consequences,
but it's still not very desirable. Fix by checking that the input
has the expected form.
Similarly, DecodeNumberField only expects to deal with fields that
contain a decimal point and digit(s), but it's sometimes abused to
parse strings that might not look like that. This could result in
failure to reject bogus input, yielding silly results. Again, fix
by rejecting input that doesn't look as-expected. That decision
also means that we can affirmatively answer the very old comment
questioning whether we couldn't save some duplicative code by
using ParseFractionalSecond here.
While these changes should only reject input that nobody would
consider valid, it still doesn't seem like a change to make in
stable branches. Apply to HEAD only.
Reported-by: Evgeniy Gorbanev <[email protected]>
Author: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
The code that translates SIMILAR TO pattern matching expressions to
POSIX-style regular expressions did not consider that square brackets
can be nested. For example, in an expression like [[:alpha:]%_], the
logic replaced the placeholders '_' and '%' but it should not.
This commit fixes the conversion logic by tracking the nesting level of
square brackets marking character class areas, while considering that
in expressions like []] or [^]] the first closing square bracket is a
regular character. Multiple tests are added to show how the conversions
should or should not apply applied while in a character class area, with
specific cases added for all the characters converted outside character
classes like an opening parenthesis '(', dollar sign '$', etc.
Author: Laurenz Albe <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Reviewed-by: Michael Paquier <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 13
|
|
Due to concerns raised about the approach, and memory leaks found
in sensitive contexts the functionality is reverted. This reverts
commits 45e7e8ca9, f8c115a6c, d2a1ed172, 55ef7abf8 and 042a66291
for v18 with an intent to revisit this patch for v19.
Discussion: https://postgr.es/m/[email protected]
|
|
xmltotext_with_options sometimes tries to replace the existing
root node of a libxml2 document. In that case xmlDocSetRootElement
will unlink and return the old root node; if we fail to free it,
it's leaked for the remainder of the session. The amount of memory
at stake is not large, a couple hundred bytes per occurrence, but
that could still become annoying in heavy usage.
Our only other xmlDocSetRootElement call is not at risk because
it's working on a just-created document, but let's modify that
code too to make it clear that it's dependent on that.
Author: Tom Lane <[email protected]>
Reviewed-by: Jim Jones <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 16
|
|
In the grammar, <expr> is a c_expr, which accepts only a limited set
of integer literals and simple expressions without parens. The
deparsing logic didn't quite match the grammar rule, and failed to use
parens e.g. for "5::bigint".
To fix, always surround the expression with parens. Would be nice to
omit the parens in simple cases, but unfortunately it's non-trivial to
detect such simple cases. Even if the expression is a simple literal
123 in the original query, after parse analysis it becomes a FuncExpr
with COERCE_IMPLICIT_CAST rather than a simple Const.
Reported-by: yonghao lee
Backpatch-through: 13
Discussion: https://www.postgresql.org/message-id/[email protected]
|
|
The comment describes the order in which fields are sent, and it had one
of the fields in the wrong place.
This has been wrong since e6dbcb72fafa (2008), so backpatch all the way
back.
Author: Emre Hasegeli <[email protected]>
Discussion: https://postgr.es/m/CAE2gYzzf38bR_R=izhpMxAmqHXKeM5ajkmukh4mNs_oXfxcMCA@mail.gmail.com
|
|
Added by commit 042a66291b04, no backpatch needed.
|
|
I forgot to run pgindent in d8555e522.
Reported-by: Fujii Masao <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
Author: Junwang Zhao <[email protected]>
Discussion: https://postgr.es/m/CAEG8a3+MRwDKc4YSFKKPKq7Y+vMufVC5u94wM5KZPB2CbgCxnQ@mail.gmail.com
|
|
To estimate with extended statistics, we need to clear the varnullingrels
field in the expression, and duplicates are not allowed in the GroupVarInfo
list. We might re-use add_unique_group_var(), but we don't do so for two
reasons.
1) We must keep the origin_rinfos list ordered exactly the same way as
varinfos.
2) add_unique_group_var() is designed for estimate_num_groups(), where a
larger number of groups is worse. While estimating the number of hash
buckets, we have the opposite: a lesser number of groups is worse.
Therefore, we don't have to remove "known equal" vars: the removed var
may valuably contribute to the multivariate statistics to grow the number
of groups.
This commit adds custom code to estimate_multivariate_bucketsize() to
initialize varinfos properly.
Reported-by: Robins Tharakan <[email protected]>
Discussion: https://postgr.es/m/18885-da51324078588253%40postgresql.org
Author: Andrei Lepikhov <[email protected]>
Reviewed-by: David Rowley <[email protected]>
Reviewed-by: Tomas Vondra <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
|
|
Word boundaries are based on whether a character is alphanumeric or
not. For the PG_UNICODE_FAST collation, alphanumeric includes
non-ASCII digits; whereas for the PG_C_UTF8 collation, it only
includes digits 0-9. Pass down the right information from the
pg_locale_t into initcap_wbnext to differentiate the behavior.
Reported-by: Noah Misch <[email protected]>
Reviewed-by: Noah Misch <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
Similar to 84fd3bc14 but these ones were found using a regex that can span
multiple lines.
Author: David Rowley <[email protected]>
Discussion: https://postgr.es/m/CAApHDvrMcr8XD107H3NV=WHgyBcu=sx5+7=WArr-n_cWUqdFXQ@mail.gmail.com
|
|
These are all new to v18
Author: David Rowley <[email protected]>
Discussion: https://postgr.es/m/CAApHDvrMcr8XD107H3NV=WHgyBcu=sx5+7=WArr-n_cWUqdFXQ@mail.gmail.com
|
|
The large majority of these have been introduced by recent commits done
in the v18 development cycle.
Author: Alexander Lakhin <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
Commit 0bada39c83a150079567a6e97b1a25a198f30ea3 fixed a bug of this kind,
which existed in all branches for six days before detection. While the
probability of reaching the trouble was low, the disruption was extreme. No
new backends could start, and service restoration needed an immediate
shutdown. Hence, add this to catch the next bug like it.
The new check in RelationIdGetRelation() suffices to make autovacuum detect
the bug in commit 243e9b40f1b2dd09d6e5bf91ebf6e822a2cd3704 that led to commit
0bada39. This also checks in a number of similar places. It replaces each
Assert(IsTransactionState()) that pertained to a conditional catalog read.
No back-patch for now, but a back-patch of commit 243e9b4 should back-patch
this, too. A back-patch could omit the src/test/regress changes, since back
branches won't gain new index columns.
Reported-by: Alexander Lakhin <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]
|
|
estimate_multivariate_ndistinct() is coded to assume the caller handles
passing it a list of GroupVarInfos with unique 'var' fields over the
entire list. 6bb6a62f3 added code which didn't ensure this and that
could result in estimate_multivariate_ndistinct() erroring out with:
ERROR: corrupt MVNDistinct entry
This occurred because estimate_multivariate_ndistinct() first searches
for a set of stats that match to at least two of the given GroupVarInfos
and then later assumes that the MVNDistinctItem.items array of the
best matching stats will have an entry for those two columns. If the
GroupVarInfos List contained a duplicate entry then the same column could
be matched to twice and that could trick the code into thinking we have
>= 2 columns matched in cases where only a single distinct column has been
matched. This could result in a failure to find the correct
MVNDistinctItem in the stats as the array containing those never
contains an item for single columns.
Here we make it more clear that the function needs a distinct set of
GroupVarInfos and also tidy up a few other comments to make things a bit
easier to follow.
Author: David Rowley <[email protected]>
Discussion: https://postgr.es/m/CAApHDvocZCUhM9W9mJ39d6oQz7ePKoqFnao_347mvC-A7QatcQ@mail.gmail.com
|
|
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in a few places. These
inconsistencies were all introduced during Postgres 18 development.
This commit was written with help from clang-tidy, by mechanically
applying the same rules as similar clean-up commits (the earliest such
commit was commit 035ce1fe).
|
|
Similar to 8461424fd, here we adjust a few new locations which were not
using the most suitable appendStringInfo* function for the intended
purpose.
Author: David Rowley <[email protected]
Discussion: https://postgr.es/m/CAApHDvqJnNjueb=Eoj8K+8n0g7nj_AcPWSiCj5RNV4fDejAfqA@mail.gmail.com
|
|
The global variable backing the DSA area for Memory Context stats
reporting had a too generic name, rename to be more descriptive.
Independently reported by Peter and Laurenz.
Author: Daniel Gustafsson <[email protected]>
Reported-by: Peter Eisentraut <[email protected]>
Reported-by: Laurenz Albe <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]
|
|
By inspection, ip_addrsize() can't return a negative result.
(If it could, we'd have way bigger problems elsewhere.)
So delete useless check in network_send(). Most C compilers
are probably perfectly capable of removing this code by
themselves, but it's confusing/misleading.
Bug: #18889
Reported-by: Daniel Elishakov <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
This adds a function for retrieving memory context statistics
and information from backends as well as auxiliary processes.
The intended usecase is cluster debugging when under memory
pressure or unanticipated memory usage characteristics.
When calling the function it sends a signal to the specified
process to submit statistics regarding its memory contexts
into dynamic shared memory. Each memory context is returned
in detail, followed by a cumulative total in case the number
of contexts exceed the max allocated amount of shared memory.
Each process is limited to use at most 1Mb memory for this.
A summary can also be explicitly requested by the user, this
will return the TopMemoryContext and a cumulative total of
all lower contexts.
In order to not block on busy processes the caller specifies
the number of seconds during which to retry before timing out.
In the case where no statistics are published within the set
timeout, the last known statistics are returned, or NULL if
no previously published statistics exist. This allows dash-
board type queries to continually publish even if the target
process is temporarily congested. Context records contain a
timestamp to indicate when they were submitted.
Author: Rahila Syed <[email protected]>
Reviewed-by: Daniel Gustafsson <[email protected]>
Reviewed-by: Andres Freund <[email protected]>
Reviewed-by: Tomas Vondra <[email protected]>
Reviewed-by: Atsushi Torikoshi <[email protected]>
Reviewed-by: Fujii Masao <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
Discussion: https://postgr.es/m/CAH2L28v8mc9HDt8QoSJ8TRmKau_8FM_HKS41NeO9-6ZAkuZKXw@mail.gmail.com
|
|
palloc() is invoked with a specific formula for its allocation size in
quote_literal_cstr(). This wastes some memory, but the size is large
enough to cover even the worst-case scenarios.
No explanations were given about the reasons behind these numbers. This
commit adds more documentation about all that.
Author: Steve Chavez <[email protected]>
Discussion: https://postgr.es/m/CAGRrpzZ9bToRWS+fAnjxDJrxwZN1QcJ-y1Pn2yg=Hst6rydLtw@mail.gmail.com
|
|
There were several places in ordering-related planning where a
requirement for btree was hardcoded but an amcanorder index could
suffice. This fixes that. We just need to do the necessary mapping
between strategy numbers and compare types and adjust some related
APIs so that this works independent of btree strategy numbers. For
instance, non-btree amcanorder indexes can now be used to support
sorting and merge joins. Also, predtest.c works independent of btree
strategy numbers now.
To avoid performance regressions, some details on btree and other
built-in index types are still hardcoded as shortcuts, but other index
types now have access to the same features by providing the required
flags and callbacks.
Author: Mark Dilger <[email protected]>
Co-authored-by: Peter Eisentraut <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/[email protected]
|
|
Teach nbtree multi-column index scans to opportunistically skip over
irrelevant sections of the index given a query with no "=" conditions on
one or more prefix index columns. When nbtree is passed input scan keys
derived from a predicate "WHERE b = 5", new nbtree preprocessing steps
output "WHERE a = ANY(<every possible 'a' value>) AND b = 5" scan keys.
That is, preprocessing generates a "skip array" (and an output scan key)
for the omitted prefix column "a", which makes it safe to mark the scan
key on "b" as required to continue the scan. The scan is therefore able
to repeatedly reposition itself by applying both the "a" and "b" keys.
A skip array has "elements" that are generated procedurally and on
demand, but otherwise works just like a regular ScalarArrayOp array.
Preprocessing can freely add a skip array before or after any input
ScalarArrayOp arrays. Index scans with a skip array decide when and
where to reposition the scan using the same approach as any other scan
with array keys. This design builds on the design for array advancement
and primitive scan scheduling added to Postgres 17 by commit 5bf748b8.
Testing has shown that skip scans of an index with a low cardinality
skipped prefix column can be multiple orders of magnitude faster than an
equivalent full index scan (or sequential scan). In general, the
cardinality of the scan's skipped column(s) limits the number of leaf
pages that can be skipped over.
The core B-Tree operator classes on most discrete types generate their
array elements with the help of their own custom skip support routine.
This infrastructure gives nbtree a way to generate the next required
array element by incrementing (or decrementing) the current array value.
It can reduce the number of index descents in cases where the next
possible indexable value frequently turns out to be the next value
stored in the index. Opclasses that lack a skip support routine fall
back on having nbtree "increment" (or "decrement") a skip array's
current element by setting the NEXT (or PRIOR) scan key flag, without
directly changing the scan key's sk_argument. These sentinel values
behave just like any other value from an array -- though they can never
locate equal index tuples (they can only locate the next group of index
tuples containing the next set of non-sentinel values that the scan's
arrays need to advance to).
A skip array's range is constrained by "contradictory" inequality keys.
For example, a skip array on "x" will only generate the values 1 and 2
given a qual such as "WHERE x BETWEEN 1 AND 2 AND y = 66". Such a skip
array qual usually has near-identical performance characteristics to a
comparable SAOP qual "WHERE x = ANY('{1, 2}') AND y = 66". However,
improved performance isn't guaranteed. Much depends on physical index
characteristics.
B-Tree preprocessing is optimistic about skipping working out: it
applies static, generic rules when determining where to generate skip
arrays, which assumes that the runtime overhead of maintaining skip
arrays will pay for itself -- or lead to only a modest performance loss.
As things stand, these assumptions are much too optimistic: skip array
maintenance will lead to unacceptable regressions with unsympathetic
queries (queries whose scan can't skip over many irrelevant leaf pages).
An upcoming commit will address the problems in this area by enhancing
_bt_readpage's approach to saving cycles on scan key evaluation, making
it work in a way that directly considers the needs of = array keys
(particularly = skip array keys).
Author: Peter Geoghegan <[email protected]>
Reviewed-By: Masahiro Ikeda <[email protected]>
Reviewed-By: Heikki Linnakangas <[email protected]>
Reviewed-By: Matthias van de Meent <[email protected]>
Reviewed-By: Tomas Vondra <[email protected]>
Reviewed-By: Aleksander Alekseev <[email protected]>
Reviewed-By: Alena Rybakina <[email protected]>
Discussion: https://postgr.es/m/CAH2-Wzmn1YsLzOGgjAQZdn1STSG_y8qP__vggTaPAYXJP+G4bw@mail.gmail.com
|
|
Fix for commit 9ef1851685b: We have to skip indexes where sortopfamily
is NULL. This takes the place of the previous btree check. Detected
by valgrind on the buildfarm.
|
|
This was previously not supported because the btree strategy numbers
were hardcoded. Now we can support this for any index that has the
required strategy mapping support and the required operators.
If an index scan used for get_actual_variable_range() requires
recheck, we now just ignore it instead of erroring out. With btree we
knew this couldn't happen, but now it might.
Author: Mark Dilger <[email protected]>
Co-authored-by: Peter Eisentraut <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/[email protected]
|
|
compareentry() is declared to work on WordEntryIN structs, but
tsvectorrecv() is using it in two places to work on WordEntry
structs. This is almost okay, since WordEntry is the first
field of WordEntryIN. But on machines with 8-byte pointers,
WordEntryIN will have a larger alignment spec than WordEntry,
and it's at least theoretically possible that the compiler
could generate code that depends on the larger alignment.
Given the lack of field reports, this may be just a hypothetical bug
that upsets nothing except sanitizer tools. Or it may be real on
certain hardware but nobody's tried to use tsvectorrecv() on such
hardware. In any case we should fix it, and the fix is trivial:
just change compareentry() so that it works on WordEntry without any
mention of WordEntryIN. We can also get rid of the quite-useless
intermediate function WordEntryCMP.
Bug: #18875
Reported-by: Alexander Lakhin <[email protected]>
Author: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 13
|
|
For GiST, having a sortsupport function allows building the index
using the "sorted build" method, which is much faster.
For b-tree, the sortsupport routine doesn't give any new
functionality, but speeds up sorting a tiny bit. The difference is not
very significant, about 2% in cursory testing on my laptop, because
the range type comparison function has quite a lot of overhead from
detoasting. In any case, since we have the function for GiST anyway,
we might as well register it for the btree opfamily too.
Author: Bernd Helmle <[email protected]>
Discussion: https://www.postgresql.org/message-id/[email protected]
|
|
Create a function that will sort the elements of an array
according to the element type's sort order. If the array
has more than one dimension, the sub-arrays of the first
dimension are sorted per normal array-comparison rules,
leaving their contents alone.
In support of this, add pg_type.typarray to the set of fields
cached by the typcache.
Author: Junwang Zhao <[email protected]>
Co-authored-by: Jian He <[email protected]>
Reviewed-by: Aleksander Alekseev <[email protected]>
Discussion: https://postgr.es/m/CAEG8a3J41a4dpw_-F94fF-JPRXYxw-GfsgoGotKcjs9LVfEEvw@mail.gmail.com
|
|
Continuation of work started in commit 15a79c73, after initial trial.
Author: Thomas Munro <[email protected]>
Discussion: https://postgr.es/m/b936d2fb-590d-49c3-a615-92c3a88c6c19%40eisentraut.org
|
|
The uuidv7_interval() function previously converted a shifted
microsecond-precision timestamp (64-bit integer) to another 64-bit
integer representing a timestamp with nanosecond precision. This
conversion caused overflow for dates beyond the year 2262. The
millisecond and sub-millisecond parts were then extracted from this
nanosecond-precision timestamp and stored in UUIDv7 values.
With this commit, the millisecond and sub-millisecond parts are stored
directly into the UUIDv7 value without being converted back to a
nanosecond precision timestamp. Following RFC 9562, the timestamp is
stored as an unsigned integer, enabling support for dates up to the
year 10889.
Reported and fixed by Andrey Borodin, with cosmetic changes and
regression tests by me.
Reported-by: Andrey Borodin <[email protected]>
Author: Andrey Borodin <[email protected]>
Discussion: https://postgr.es/m/[email protected]
|
|
This removes some setlocale() calls and a lot of commentary about how
dangerous that is. strftime_l() is from POSIX 2008, and on Windows we
use _wcsftime_l().
While here, adjust error message for strftime_l() failure: it does not
in practice set errno (even though POSIX says it could), so no %m.
Author: Thomas Munro <[email protected]>
Reviewed-by: Heikki Linnakangas <[email protected]>
Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/CA%2BhUKGJqVe0%2BPv9dvC9dSums_PXxGo9SWcxYAMBguWJUGbWz-A%40mail.gmail.com
|