Commit Graph

2848 Commits

Author SHA1 Message Date
Tom Lane b9b21acc76 In extensions, don't replace objects not belonging to the extension.
Previously, if an extension script did CREATE OR REPLACE and there was
an existing object not belonging to the extension, it would overwrite
the object and adopt it into the extension.  This is problematic, first
because the overwrite is probably unintentional, and second because we
didn't change the object's ownership.  Thus a hostile user could create
an object in advance of an expected CREATE EXTENSION command, and would
then have ownership rights on an extension object, which could be
modified for trojan-horse-type attacks.

Hence, forbid CREATE OR REPLACE of an existing object unless it already
belongs to the extension.  (Note that we've always forbidden replacing
an object that belongs to some other extension; only the behavior for
previously-free-standing objects changes here.)

For the same reason, also fail CREATE IF NOT EXISTS when there is
an existing object that doesn't belong to the extension.

Our thanks to Sven Klemm for reporting this problem.

Security: CVE-2022-2625
2022-08-08 11:12:31 -04:00
David Rowley 1349d2790b Improve performance of ORDER BY / DISTINCT aggregates
ORDER BY / DISTINCT aggreagtes have, since implemented in Postgres, been
executed by always performing a sort in nodeAgg.c to sort the tuples in
the current group into the correct order before calling the transition
function on the sorted tuples.  This was not great as often there might be
an index that could have provided pre-sorted input and allowed the
transition functions to be called as the rows come in, rather than having
to store them in a tuplestore in order to sort them once all the tuples
for the group have arrived.

Here we change the planner so it requests a path with a sort order which
supports the most amount of ORDER BY / DISTINCT aggregate functions and
add new code to the executor to allow it to support the processing of
ORDER BY / DISTINCT aggregates where the tuples are already sorted in the
correct order.

Since there can be many ORDER BY / DISTINCT aggregates in any given query
level, it's very possible that we can't find an order that suits all of
these aggregates.  The sort order that the planner chooses is simply the
one that suits the most aggregate functions.  We take the most strictly
sorted variation of each order and see how many aggregate functions can
use that, then we try again with the order of the remaining aggregates to
see if another order would suit more aggregate functions.  For example:

SELECT agg(a ORDER BY a),agg2(a ORDER BY a,b) ...

would request the sort order to be {a, b} because {a} is a subset of the
sort order of {a,b}, but;

SELECT agg(a ORDER BY a),agg2(a ORDER BY c) ...

would just pick a plan ordered by {a} (we give precedence to aggregates
which are earlier in the targetlist).

SELECT agg(a ORDER BY a),agg2(a ORDER BY b),agg3(a ORDER BY b) ...

would choose to order by {b} since two aggregates suit that vs just one
that requires input ordered by {a}.

Author: David Rowley
Reviewed-by: Ronan Dunklau, James Coleman, Ranier Vilela, Richard Guo, Tom Lane
Discussion: https://postgr.es/m/CAApHDvpHzfo92%3DR4W0%2BxVua3BUYCKMckWAmo-2t_KiXN-wYH%3Dw%40mail.gmail.com
2022-08-02 23:11:45 +12:00
Tom Lane 83f1793d60 Check maximum number of columns in function RTEs, too.
I thought commit fd96d14d9 had plugged all the holes of this sort,
but no, function RTEs could produce oversize tuples too, either
via long coldeflists or just from multiple functions in one RTE.
(I'm pretty sure the other variants of base RTEs aren't a problem,
because they ultimately refer to either a table or a sub-SELECT,
whose widths are enforced elsewhere.  But we explicitly allow join
RTEs to be overwidth, as long as you don't try to form their
tuple result.)

Per further discussion of bug #17561.  As before, patch all branches.

Discussion: https://postgr.es/m/17561-80350151b9ad2ad4@postgresql.org
2022-08-01 12:22:35 -04:00
Tom Lane fd96d14d95 In transformRowExpr(), check for too many columns in the row.
A RowExpr with more than MaxTupleAttributeNumber columns would fail at
execution anyway, since we cannot form a tuple datum with more than that
many columns.  While heap_form_tuple() has a check for too many columns,
it emerges that there are some intermediate bits of code that don't
check and can be driven to failure with sufficiently many columns.
Checking this at parse time seems like the most appropriate place to
install a defense, since we already check SELECT list length there.

While at it, make the SELECT-list-length error use the same errcode
(TOO_MANY_COLUMNS) as heap_form_tuple does, rather than the generic
PROGRAM_LIMIT_EXCEEDED.

Per bug #17561 from Egor Chindyaskin.  The given test case crashes
in all supported branches (and probably a lot further back),
so patch all.

Discussion: https://postgr.es/m/17561-80350151b9ad2ad4@postgresql.org
2022-07-29 13:31:10 -04:00
Michael Paquier 0a5f06b84d Fix a few issues with REINDEX grammar
This addresses a couple of bugs in the REINDEX grammar, introduced by
83011ce:
- A name was never specified for DATABASE/SYSTEM, even if the query
included one.  This caused such REINDEX queries to always work with any
object name, but we should complain if the object name specified does
not match the name of the database we are connected to.  A test is added
for this case in the main regression test suite, provided by Álvaro.
- REINDEX SYSTEM CONCURRENTLY [name] was getting rejected in the
parser.  Concurrent rebuilds are not supported for catalogs but the
error provided at execution time is more helpful for the user, and
allowing this flavor results in a simplification of the parsing logic.
- REINDEX DATABASE CONCURRENTLY was rebuilding the index in a
non-concurrent way, as the option was not being appended correctly in
the list of DefElems in ReindexStmt (REINDEX (CONCURRENTLY) DATABASE was
working fine.  A test is added in the TAP tests of reindexdb for this
case, where we already have a REINDEX DATABASE CONCURRENTLY query
running on a small-ish instance.  This relies on the work done in
2cbc3c1 for SYSTEM, but here we check if the OIDs of the index relations
match or not after the concurrent rebuild.  Note that in order to get
this part to work, I had to tweak the tests so as the index OID and
names are saved separately.  This change not affect the reliability or
of the coverage of the existing tests.

While on it, I have implemented a tweak in the grammar to reduce the
parsing by one branch, simplifying things even more.

Author: Michael Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/YttqI6O64wDxGn0K@paquier.xyz
2022-07-26 10:16:26 +09:00
Alvaro Herrera 83011ce7d7
Rework grammar for REINDEX
The part of grammar have grown needlessly duplicative and more complex
that necessary.  Rewrite.

Reviewed-by: Michaël Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20220721174212.cmitjpuimx6ssyyj@alvherre.pgsql
2022-07-22 19:23:39 +02:00
Alvaro Herrera 7d158e8cb4
parser: centralize common auxiliary productions
Things like "opt_name" can well be shared by various commands rather
than there being multiple definitions of the same thing.  Rename these
productions and move them to appear together in gram.y, which may
improve chances of reuse in the future.

Discussion: https://postgr.es/m/20220721174212.cmitjpuimx6ssyyj@alvherre.pgsql
2022-07-22 13:13:20 +02:00
Alvaro Herrera 9853bf6ab0
Update src/backend/parser/README
New files have been added to this directory, but not listed here.
Repair.
2022-07-22 12:56:21 +02:00
Dean Rasheed 624aa2a13b Make the name optional in CREATE STATISTICS.
This allows users to omit the statistics name in a CREATE STATISTICS
command, letting the system auto-generate a sensible, unique name,
putting the statistics object in the same schema as the table.

Simon Riggs, reviewed by Matthias van de Meent.

Discussion: https://postgr.es/m/CANbhV-FGD2d_C3zFTfT2aRfX_TaPSgOeKES58RLZx5XzQp5NhA@mail.gmail.com
2022-07-21 19:23:13 +01:00
Tom Lane b9654cecea Fix ruleutils issues with dropped cols in functions-returning-composite.
Due to lack of concern for the case in the dependency code, it's
possible to drop a column of a composite type even though stored
queries have references to the dropped column via functions-in-FROM
that return the composite type.  There are "soft" references,
namely FROM-clause aliases for such columns, and "hard" references,
that is actual Vars referring to them.  The right fix for hard
references is to add dependencies preventing the drop; something
we've known for many years and not done (and this commit still doesn't
address it).  A "soft" reference shouldn't prevent a drop though.
We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but
nobody had noticed that the current behavior can result in dump/reload
failures, because ruleutils.c can print more column aliases than the
underlying composite type now has.  So we need to rejigger the
column-alias-handling code to treat such columns as dropped and not
print aliases for them.

Rather than writing new code for this, I used expandRTE() which already
knows how to figure out which function result columns are dropped.
I'd initially thought maybe we could use expandRTE() in all cases, but
that fails for EXPLAIN's purposes, because the planner strips a lot of
RTE infrastructure that expandRTE() needs.  So this patch just uses it
for unplanned function RTEs and otherwise does things the old way.

If there is a hard reference (Var), then removing the column alias
causes us to fail to print the Var, since there's no longer a name
to print.  Failing seems less desirable than printing a made-up
name, so I made it print "?dropped?column?" instead.

Per report from Timo Stolz.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
2022-07-21 13:56:02 -04:00
Dean Rasheed bcedd8f5fc Make subquery aliases optional in the FROM clause.
This allows aliases for sub-SELECTs and VALUES clauses in the FROM
clause to be omitted.

This is an extension of the SQL standard, supported by some other
database systems, and so eases the transition from such systems, as
well as removing the minor inconvenience caused by requiring these
aliases.

Patch by me, reviewed by Tom Lane.

Discussion: https://postgr.es/m/CAEZATCUCGCf82=hxd9N5n6xGHPyYpQnxW8HneeH+uP7yNALkWA@mail.gmail.com
2022-07-20 09:29:42 +01:00
Michael Paquier 12c254c99f Tweak detail and hint messages to be consistent with project policy
Detail and hint messages should be full sentences and should end with a
period, but some of the messages newly-introduced in v15 did not follow
that.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20220719120948.GF12702@telsasoft.com
Backpatch-through: 15
2022-07-20 09:50:12 +09:00
Michael Paquier 2cbc3c17a5 Rework logic and simplify syntax of REINDEX DATABASE/SYSTEM
Per discussion, this commit includes a couple of changes to these two
flavors of REINDEX:
* The grammar is changed to make the name of the object optional, hence
one can rebuild all the indexes of the wanted area by specifying only
"REINDEX DATABASE;" or "REINDEX SYSTEM;".  Previously, the object name
was mandatory and had to match the name of the database on which the
command is issued.
* REINDEX DATABASE is changed to ignore catalogs, making this task only
possible with REINDEX SYSTEM.  This is a historical change, but there
was no way to work only on the indexes of a database without touching
the catalogs.  We have discussed more approaches here, like the addition
of an option to skip the catalogs without changing the original
behavior, but concluded that what we have here is for the best.

This builds on top of the TAP tests introduced in 5fb5b6c, showing the
change in behavior for REINDEX SYSTEM.  reindexdb is updated so as we do
not issue an extra REINDEX SYSTEM when working on a database in the
non-concurrent case, something that was confusing when --concurrently
got introduced, so this simplifies the code.

Author: Simon Riggs
Reviewed-by: Ashutosh Bapat, Bernd Helmle, Álvaro Herrera, Cary Huang,
Michael Paquier
Discussion: https://postgr.es/m/CANbhV-H=NH6Om4-X6cRjDWfH_Mu1usqwkuYVp-hwdB_PSHWRfg@mail.gmail.com
2022-07-19 11:45:06 +09:00
Peter Eisentraut 9fd45870c1 Replace many MemSet calls with struct initialization
This replaces all MemSet() calls with struct initialization where that
is easily and obviously possible.  (For example, some cases have to
worry about padding bits, so I left those.)

(The same could be done with appropriate memset() calls, but this
patch is part of an effort to phase out MemSet(), so it doesn't touch
memset() calls.)

Reviewed-by: Ranier Vilela <ranier.vf@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/9847b13c-b785-f4e2-75c3-12ec77a3b05c@enterprisedb.com
2022-07-16 08:50:49 +02:00
Peter Eisentraut 784cedda06 Allow specifying STORAGE attribute for a new table
Previously, the STORAGE specification was only available in ALTER
TABLE.  This makes it available in CREATE TABLE as well.

Also make the code and the documentation for STORAGE and COMPRESSION
attributes consistent.

Author:	Teodor Sigaev <teodor@sigaev.ru>
Author: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: wenjing zeng <wjzeng2012@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/de83407a-ae3d-a8e1-a788-920eb334f25b@sigaev.ru
2022-07-13 12:21:45 +02:00
Peter Eisentraut 503e3833ef Remove useless assertions
We don't need Assert(IsA(foo, String)) right before running
strVal(foo), since strVal() already does the assertion internally (via
castNode()).
2022-07-13 11:43:40 +02:00
Michael Paquier 0a6be1f0ec Improve error message with JSON_SERIALIZE()
The error message introduced in 3c633f3 can share the same format string
with an existing message used for JSON(), reducing the translation
effort.

Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20220708.154135.2123613118233840495.horikyota.ntt@gmail.com
Backpatch-through: 15
2022-07-11 11:20:15 +09:00
Andrew Dunstan 3c633f32b9 Only allow returning string types or bytea from json_serialize
These are documented to be the allowed types for the RETURNING clause,
but the restriction was not being enforced, which caused a segfault if
another type was specified. Add some testing for this.

Per report from a.kozhemyakin

Backpatch to release 15.
2022-07-07 17:40:02 -04:00
Dean Rasheed 8d367a44d3 Fix alias matching in transformLockingClause().
When locking a specific named relation for a FOR [KEY] UPDATE/SHARE
clause, transformLockingClause() finds the relation to lock by
scanning the rangetable for an RTE with a matching eref->aliasname.
However, it failed to account for the visibility rules of a join RTE.

If a join RTE doesn't have a user-supplied alias, it will have a
generated eref->aliasname of "unnamed_join" that is not visible as a
relation name in the parse namespace. Such an RTE needs to be skipped,
otherwise it might be found in preference to a regular base relation
with a user-supplied alias of "unnamed_join", preventing it from being
locked.

In addition, if a join RTE doesn't have a user-supplied alias, but
does have a join_using_alias, then the RTE needs to be matched using
that alias rather than the generated eref->aliasname, otherwise a
misleading "relation not found" error will be reported rather than a
"join cannot be locked" error.

Backpatch all the way, except for the second part which only goes back
to 14, where JOIN USING aliases were added.

Dean Rasheed, reviewed by Tom Lane.

Discussion: https://postgr.es/m/CAEZATCUY_KOBnqxbTSPf=7fz9HWPnZ5Xgb9SwYzZ8rFXe7nb=w@mail.gmail.com
2022-07-07 13:08:08 +01:00
Robert Haas b0a55e4329 Change internal RelFileNode references to RelFileNumber or RelFileLocator.
We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.

Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".

Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.

On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.

Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.

Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.

Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com
2022-07-06 11:39:09 -04:00
Peter Eisentraut d746021de1 Add construct_array_builtin, deconstruct_array_builtin
There were many calls to construct_array() and deconstruct_array() for
built-in types, for example, when dealing with system catalog columns.
These all hardcoded the type attributes necessary to pass to these
functions.

To simplify this a bit, add construct_array_builtin(),
deconstruct_array_builtin() as wrappers that centralize this hardcoded
knowledge.  This simplifies many call sites and reduces the amount of
hardcoded stuff that is spread around.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/2914356f-9e5f-8c59-2995-5997fc48bcba%40enterprisedb.com
2022-07-01 11:23:15 +02:00
Peter Eisentraut 2172455865 Fix collation of JSON_TABLE output columns
The output columns of JSON_TABLE should have the collations of their
data type.  The existing implementation sets the default collation if
the type is collatable.

Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://www.postgresql.org/message-id/flat/9d75ce67-0121-5050-5bec-bf5009db55ce%40enterprisedb.com
2022-06-10 06:05:08 +02:00
Tom Lane 5f0adec253 Make STRING an unreserved_keyword.
Commit 1a36bc9db (SQL/JSON query functions) introduced STRING as a
type_func_name_keyword, thereby breaking applications that use
"string" as a table name, column name, function parameter name, etc.
That seems like a pretty bad thing, not least because the SQL spec
says that STRING is an unreserved keyword.

This is easy enough to fix so far as the core grammar is concerned.
However, doing so causes some ECPG test cases to fail, specifically
those that use "string" as a typedef name.  It turns out this is
because portions of the ECPG grammar allow type_func_name_keywords
but not unreserved_keywords as typedef names.  That's pretty horrid,
and it's mildly astonishing that we've not heard complaints about it
before.  We can fix two of those uses trivially, but the ones in the
var_type production are less easy.  As a stopgap, hard-code STRING as
an allowed alternative in var_type.

Per report from Alastair McKinley.

Discussion: https://postgr.es/m/3661437.1653855582@sss.pgh.pa.us
2022-05-30 14:05:20 -04:00
David Rowley 3e9abd2eb1 Teach remove_unused_subquery_outputs about window run conditions
9d9c02ccd added code to allow the executor to take shortcuts when quals
on monotonic window functions guaranteed that once the qual became false
it could never become true again.  When possible, baserestrictinfo quals
are converted to become these quals, which we call run conditions.

Unfortunately, in 9d9c02ccd, I forgot to update
remove_unused_subquery_outputs to teach it about these run conditions.
This could cause a WindowFunc column which was unused in the target list
but referenced by an upper-level WHERE clause to be removed from the
subquery when the qual in the WHERE clause was converted into a window run
condition.  Because of this, the entire WindowClause would be removed from
the query resulting in additional rows making it into the resultset when
they should have been filtered out by the WHERE clause.

Here we fix this by recording which target list items in the subquery have
run conditions. That gets passed along to remove_unused_subquery_outputs
to tell it not to remove these items from the target list.

Bug: #17495
Reported-by: Jeremy Evans
Reviewed-by: Richard Guo
Discussion: https://postgr.es/m/17495-7ffe2fa0b261b9fa@postgresql.org
2022-05-27 10:37:58 +12:00
Alvaro Herrera 0fbf011200
Check column list length in XMLTABLE/JSON_TABLE alias
We weren't checking the length of the column list in the alias clause of
an XMLTABLE or JSON_TABLE function (a "tablefunc" RTE), and it was
possible to make the server crash by passing an overly long one.  Fix it
by throwing an error in that case, like the other places that deal with
alias lists.

In passing, modify the equivalent test used for join RTEs to look like
the other ones, which was different for no apparent reason.

This bug came in when XMLTABLE was born in version 10; backpatch to all
stable versions.

Reported-by: Wang Ke <krking@zju.edu.cn>
Discussion: https://postgr.es/m/17480-1c9d73565bb28e90@postgresql.org
2022-05-18 20:28:31 +02:00
Tom Lane 3ab9a63cb6 Rename JsonIsPredicate.value_type, fix JSON backend/nodes/ infrastructure.
I started out with the intention to rename value_type to item_type to
avoid a collision with a typedef name that appears on some platforms.

Along the way, I noticed that the adjacent field "format" was not being
correctly handled by the backend/nodes/ infrastructure functions:
copyfuncs.c erroneously treated it as a scalar, while equalfuncs,
outfuncs, and readfuncs omitted handling it at all.  This looks like
it might be cosmetic at the moment because the field is always NULL
after parse analysis; but that's likely a bug in itself, and the code's
certainly not very future-proof.  Let's fix it while we can still do so
without forcing an initdb on beta testers.

Further study found a few other inconsistencies in the backend/nodes/
infrastructure for the recently-added JSON node types, so fix those too.

catversion bumped because of potential change in stored rules.

Discussion: https://postgr.es/m/526703.1652385613@sss.pgh.pa.us
2022-05-13 11:40:08 -04:00
Peter Eisentraut 30ed71e423 Indent C code in flex and bison files
In the style of pgindent, done semi-manually.

Discussion: https://www.postgresql.org/message-id/flat/7d062ecc-7444-23ec-a159-acd8adf9b586%40enterprisedb.com
2022-05-13 07:17:29 +02:00
Tom Lane 23e7b38bfe Pre-beta mechanical code beautification.
Run pgindent, pgperltidy, and reformat-dat-files.
I manually fixed a couple of comments that pgindent uglified.
2022-05-12 15:17:30 -04:00
Michael Paquier 45edde037e Fix typos and grammar in code and test comments
This fixes the grammar of some comments in a couple of tests (SQL and
TAP), and in some C files.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220511020334.GH19626@telsasoft.com
2022-05-11 15:38:55 +09:00
Tom Lane fe20afaee8 Fix core dump in transformValuesClause when there are no columns.
The parser code that transformed VALUES from row-oriented to
column-oriented lists failed if there were zero columns.
You can't write that straightforwardly (though probably you
should be able to), but the case can be reached by expanding
a "tab.*" reference to a zero-column table.

Per bug #17477 from Wang Ke.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/17477-0af3c6ac6b0a6ae0@postgresql.org
2022-05-09 14:15:37 -04:00
Peter Eisentraut dc2be6ed47 Remove JsonPathSpec typedef
It doesn't seem very useful, and it's a bit in the way of the planned
node support automation.

Discussion: https://www.postgresql.org/message-id/202204191140.3wsbevfhqmu3@alvherre.pgsql
2022-05-04 17:36:31 +02:00
Tom Lane 36d4efe779 Avoid invalid array reference in transformAlterTableStmt().
Don't try to look at the attidentity field of system attributes,
because they're not there in the TupleDescAttr array.  Sometimes
this is harmless because we accidentally pick up a zero, but
otherwise we'll report "no owned sequence found" from an attempt
to alter a system attribute.  (It seems possible that a SIGSEGV
could occur, too, though I've not seen it in testing.)

It's not in this function's charter to complain that you can't
alter a system column, so instead just hard-wire an assumption
that system attributes aren't identities.  I didn't bother with
a regression test because the appearance of the bug is very
erratic.

Per bug #17465 from Roman Zharkov.  Back-patch to all supported
branches.  (There's not actually a live bug before v12, because
before that get_attidentity() did the right thing anyway.
But for consistency I changed the test in the older branches too.)

Discussion: https://postgr.es/m/17465-f2a554a6cb5740d3@postgresql.org
2022-04-18 12:16:45 -04:00
Andrew Dunstan f7a605f636 Small cleanups in SQL/JSON code
These are to keep Coverity happy. In one case remove a redundant NULL
check, and in another explicitly ignore a function result that is already
known.
2022-04-15 07:49:20 -04:00
Andrew Dunstan 4cd8717af3 Improve a couple of sql/json error messages
Fix the grammar in two, and add a hint to one.
2022-04-14 10:26:29 -04:00
Andrew Dunstan fcdb35c32a Fix transformJsonBehavior
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.
2022-04-14 09:24:22 -04:00
Alvaro Herrera ce4f46fdc8
Change mechanism to set up source targetlist in MERGE
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
2022-04-12 09:29:39 +02:00
David Rowley b0e5f02ddc Fix various typos and spelling mistakes in code comments
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
2022-04-11 20:49:41 +12:00
Michael Paquier 7597cc3083 Fix the dates of some copyright notices
0ad8032 and 4e34747 are at the origin of that.  Julien has found the one
in parse_jsontable.c, while I have spotted the rest.

Author: Julien Rouhaud, Michael Paquier
Discussion: https://postgr.es/m/20220411060838.ftnzyvflpwu6f74w@jrouhaud
2022-04-11 16:36:25 +09:00
Tomas Vondra 2c7ea57e56 Revert "Logical decoding of sequences"
This reverts a sequence of commits, implementing features related to
logical decoding and replication of sequences:

 - 0da92dc530
 - 80901b3291
 - b779d7d8fd
 - d5ed9da41d
 - a180c2b34d
 - 75b1521dae
 - 2d2232933b
 - 002c9dd97a
 - 05843b1aa4

The implementation has issues, mostly due to combining transactional and
non-transactional behavior of sequences. It's not clear how this could
be fixed, but it'll require reworking significant part of the patch.

Discussion: https://postgr.es/m/95345a19-d508-63d1-860a-f5c2f41e8d40@enterprisedb.com
2022-04-07 20:06:36 +02:00
Peter Eisentraut 344d62fb9a Unlogged sequences
Add support for unlogged sequences.  Unlike for unlogged tables, this
is not a performance feature.  It allows sequences associated with
unlogged tables to be excluded from replication.

A new subcommand ALTER SEQUENCE ... SET LOGGED/UNLOGGED is added.

An identity/serial sequence now automatically gets and follows the
persistence level (logged/unlogged) of its owning table.  (The
sequences owned by temporary tables were already temporary through the
separate mechanism in RangeVarAdjustRelationPersistence().)  But you
can still change the persistence of an owned sequence separately.
Also, pg_dump and pg_upgrade preserve the persistence of existing
sequences.

Discussion: https://www.postgresql.org/message-id/flat/04e12818-2f98-257c-b926-2845d74ed04f%402ndquadrant.com
2022-04-07 16:18:00 +02:00
Tom Lane a0ffa885e4 Allow granting SET and ALTER SYSTEM privileges on GUC parameters.
This patch allows "PGC_SUSET" parameters to be set by non-superusers
if they have been explicitly granted the privilege to do so.
The privilege to perform ALTER SYSTEM SET/RESET on a specific parameter
can also be granted.
Such privileges are cluster-wide, not per database.  They are tracked
in a new shared catalog, pg_parameter_acl.

Granting and revoking these new privileges works as one would expect.
One caveat is that PGC_USERSET GUCs are unaffected by the SET privilege
--- one could wish that those were handled by a revocable grant to
PUBLIC, but they are not, because we couldn't make it robust enough
for GUCs defined by extensions.

Mark Dilger, reviewed at various times by Andrew Dunstan, Robert Haas,
Joshua Brindle, and myself

Discussion: https://postgr.es/m/3D691E20-C1D5-4B80-8BA5-6BEB63AF3029@enterprisedb.com
2022-04-06 13:24:33 -04:00
Andrew Dunstan fadb48b00e PLAN clauses for JSON_TABLE
These clauses allow the user to specify how data from nested paths are
joined, allowing considerable freedom in shaping the tabular output of
JSON_TABLE.

PLAN DEFAULT allows the user to specify the global strategies when
dealing with sibling or child nested paths. The is often sufficient to
achieve the necessary goal, and is considerably simpler than the full
PLAN clause, which allows the user to specify the strategy to be used
for each named nested path.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zhihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/7e2cb85d-24cf-4abb-30a5-1a33715959bd@postgrespro.ru
2022-04-05 14:17:08 -04:00
Andrew Dunstan 4e34747c88 JSON_TABLE
This feature allows jsonb data to be treated as a table and thus used in
a FROM clause like other tabular data. Data can be selected from the
jsonb using jsonpath expressions, and hoisted out of nested structures
in the jsonb to form multiple rows, more or less like an outer join.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zhihong Yu (whose
name I previously misspelled), Himanshu Upadhyaya, Daniel Gustafsson,
Justin Pryzby.

Discussion: https://postgr.es/m/7e2cb85d-24cf-4abb-30a5-1a33715959bd@postgrespro.ru
2022-04-04 16:03:47 -04:00
Andrew Dunstan 9f91344223 Fix comments with "a expression" 2022-03-31 15:45:25 -04:00
Andrew Dunstan 49082c2cc3 RETURNING clause for JSON() and JSON_SCALAR()
This patch is extracted from a larger patch that allowed setting the
default returned value from these functions to json or jsonb. That had
problems, but this piece of it is fine. For these functions only json or
jsonb can be specified in the RETURNING clause.

Extracted from an original patch from Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-31 15:45:24 -04:00
Andrew Dunstan 606948b058 SQL JSON functions
This Patch introduces three SQL standard JSON functions:

JSON() (incorrectly mentioned in my commit message for f4fb45d15c)
JSON_SCALAR()
JSON_SERIALIZE()

JSON() produces json values from text, bytea, json or jsonb values, and
has facilitites for handling duplicate keys.
JSON_SCALAR() produces a json value from any scalar sql value, including
json and jsonb.
JSON_SERIALIZE() produces text or bytea from input which containis or
represents json or jsonb;

For the most part these functions don't add any significant new
capabilities, but they will be of use to users wanting standard
compliant JSON handling.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-30 16:30:37 -04:00
Andrew Dunstan 1a36bc9dba SQL/JSON query functions
This introduces the SQL/JSON functions for querying JSON data using
jsonpath expressions. The functions are:

JSON_EXISTS()
JSON_QUERY()
JSON_VALUE()

All of these functions only operate on jsonb. The workaround for now is
to cast the argument to jsonb.

JSON_EXISTS() tests if the jsonpath expression applied to the jsonb
value yields any values. JSON_VALUE() must return a single value, and an
error occurs if it tries to return multiple values. JSON_QUERY() must
return a json object or array, and there are various WRAPPER options for
handling scalar or multi-value results. Both these functions have
options for handling EMPTY and ERROR conditions.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-29 16:57:13 -04:00
Andrew Dunstan 33a377608f IS JSON predicate
This patch intrdocuces the SQL standard IS JSON predicate. It operates
on text and bytea values representing JSON as well as on the json and
jsonb types. Each test has an IS and IS NOT variant. The tests are:

IS JSON [VALUE]
IS JSON ARRAY
IS JSON OBJECT
IS JSON SCALAR
IS JSON  WITH | WITHOUT UNIQUE KEYS

These are mostly self-explanatory, but note that IS JSON WITHOUT UNIQUE
KEYS is true whenever IS JSON is true, and IS JSON WITH UNIQUE KEYS is
true whenever IS JSON is true except it IS JSON OBJECT is true and there
are duplicate keys (which is never the case when applied to jsonb values).

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-28 15:37:08 -04:00
Alvaro Herrera 7103ebb7aa
Add support for MERGE SQL command
MERGE performs actions that modify rows in the target table using a
source table or query. MERGE provides a single SQL statement that can
conditionally INSERT/UPDATE/DELETE rows -- a task that would otherwise
require multiple PL statements.  For example,

MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
  UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
  DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
  INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
  DO NOTHING;

MERGE works with regular tables, partitioned tables and inheritance
hierarchies, including column and row security enforcement, as well as
support for row and statement triggers and transition tables therein.

MERGE is optimized for OLTP and is parameterizable, though also useful
for large scale ETL/ELT. MERGE is not intended to be used in preference
to existing single SQL commands for INSERT, UPDATE or DELETE since there
is some overhead.  MERGE can be used from PL/pgSQL.

MERGE does not support targetting updatable views or foreign tables, and
RETURNING clauses are not allowed either.  These limitations are likely
fixable with sufficient effort.  Rewrite rules are also not supported,
but it's not clear that we'd want to support them.

Author: Pavan Deolasee <pavan.deolasee@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Simon Riggs <simon.riggs@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions)
Reviewed-by: Peter Geoghegan <pg@bowt.ie> (earlier versions)
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions)
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com
Discussion: https://postgr.es/m/20201231134736.GA25392@alvherre.pgsql
2022-03-28 16:47:48 +02:00
Tom Lane cc7401d5ca Fix up compiler warnings/errors from f4fb45d15.
Per early buildfarm returns.
2022-03-27 18:32:40 -04:00
Andrew Dunstan f4fb45d15c SQL/JSON constructors
This patch introduces the SQL/JSON standard constructors for JSON:

JSON()
JSON_ARRAY()
JSON_ARRAYAGG()
JSON_OBJECT()
JSON_OBJECTAGG()

For the most part these functions provide facilities that mimic
existing json/jsonb functions. However, they also offer some useful
additional functionality. In addition to text input, the JSON() function
accepts bytea input, which it will decode and constuct a json value from.
The other functions provide useful options for handling duplicate keys
and null values.

This series of patches will be followed by a consolidated documentation
patch.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-27 17:03:34 -04:00
Andrew Dunstan f79b803dcc Common SQL/JSON clauses
This introduces some of the building blocks used by the SQL/JSON
constructor and query functions. Specifically, it provides node
executor and grammar support for the FORMAT JSON [ENCODING foo]
clause, and values decorated with it, and for the RETURNING clause.

The following SQL/JSON patches will leverage these.

Nikita Glukhov (who probably deserves an award for perseverance).

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-27 17:03:33 -04:00
Tomas Vondra 923def9a53 Allow specifying column lists for logical replication
This allows specifying an optional column list when adding a table to
logical replication. The column list may be specified after the table
name, enclosed in parentheses. Columns not included in this list are not
sent to the subscriber, allowing the schema on the subscriber to be a
subset of the publisher schema.

For UPDATE/DELETE publications, the column list needs to cover all
REPLICA IDENTITY columns. For INSERT publications, the column list is
arbitrary and may omit some REPLICA IDENTITY columns. Furthermore, if
the table uses REPLICA IDENTITY FULL, column list is not allowed.

The column list can contain only simple column references. Complex
expressions, function calls etc. are not allowed. This restriction could
be relaxed in the future.

During the initial table synchronization, only columns included in the
column list are copied to the subscriber. If the subscription has
several publications, containing the same table with different column
lists, columns specified in any of the lists will be copied.

This means all columns are replicated if the table has no column list
at all (which is treated as column list with all columns), or when of
the publications is defined as FOR ALL TABLES (possibly IN SCHEMA that
matches the schema of the table).

For partitioned tables, publish_via_partition_root determines whether
the column list for the root or the leaf relation will be used. If the
parameter is 'false' (the default), the list defined for the leaf
relation is used. Otherwise, the column list for the root partition
will be used.

Psql commands \dRp+ and \d <table-name> now display any column lists.

Author: Tomas Vondra, Alvaro Herrera, Rahila Syed
Reviewed-by: Peter Eisentraut, Alvaro Herrera, Vignesh C, Ibrar Ahmed,
Amit Kapila, Hou zj, Peter Smith, Wang wei, Tang, Shi yu
Discussion: https://postgr.es/m/CAH2L28vddB_NFdRVpuyRBJEBWjz4BSyTB=_ektNRH8NJ1jf95g@mail.gmail.com
2022-03-26 01:01:27 +01:00
Tomas Vondra 002c9dd97a Handle sequences in preprocess_pubobj_list
Commit 75b1521dae added support for logical replication of sequences,
including grammar changes, but it did not update preprocess_pubobj_list
accordingly. This can cause segfaults with "continuations", i.e. when
command specifies a list of objects:

  CREATE PUBLICATION p FOR SEQUENCE s1, s2;

Reported by Amit Kapila, patch by me.

Reported-by: Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1JxDNKGBSNTyN-Xj2JRjzFo+ziSqJbjH==vuO0YF_CQrg@mail.gmail.com
2022-03-25 14:29:56 +01:00
Tomas Vondra 75b1521dae Add decoding of sequences to built-in replication
This commit adds support for decoding of sequences to the built-in
replication (the infrastructure was added by commit 0da92dc530).

The syntax and behavior mostly mimics handling of tables, i.e. a
publication may be defined as FOR ALL SEQUENCES (replicating all
sequences in a database), FOR ALL SEQUENCES IN SCHEMA (replicating
all sequences in a particular schema) or individual sequences.

To publish sequence modifications, the publication has to include
'sequence' action. The protocol is extended with a new message,
describing sequence increments.

A new system view pg_publication_sequences lists all the sequences
added to a publication, both directly and indirectly. Various psql
commands (\d and \dRp) are improved to also display publications
including a given sequence, or sequences included in a publication.

Author: Tomas Vondra, Cary Huang
Reviewed-by: Peter Eisentraut, Amit Kapila, Hannu Krosing, Andres
             Freund, Petr Jelinek
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com
Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca
2022-03-24 18:49:27 +01:00
Andrew Dunstan 1460fc5942 Revert "Common SQL/JSON clauses"
This reverts commit 865fe4d5df.

This has caused issues with a significant number of buildfarm members
2022-03-22 19:56:14 -04:00
Andrew Dunstan 865fe4d5df Common SQL/JSON clauses
This introduces some of the building blocks used by the SQL/JSON
constructor and query functions. Specifically, it provides node
executor and grammar support for the FORMAT JSON [ENCODING foo]
clause, and values decorated with it, and for the RETURNING clause.

The following SQL/JSON patches will leverage these.

Nikita Glukhov (who probably deserves an award for perseverance).

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup. Erik Rijkers, Zihong Yu and
Himanshu Upadhyaya.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
2022-03-22 17:32:54 -04:00
Amit Kapila 208c5d65bb Add ALTER SUBSCRIPTION ... SKIP.
This feature allows skipping the transaction on subscriber nodes.

If incoming change violates any constraint, logical replication stops
until it's resolved. Currently, users need to either manually resolve the
conflict by updating a subscriber-side database or by using function
pg_replication_origin_advance() to skip the conflicting transaction. This
commit introduces a simpler way to skip the conflicting transactions.

The user can specify LSN by ALTER SUBSCRIPTION ... SKIP (lsn = XXX),
which allows the apply worker to skip the transaction finished at
specified LSN. The apply worker skips all data modification changes within
the transaction.

Author: Masahiko Sawada
Reviewed-by: Takamichi Osumi, Hou Zhijie, Peter Eisentraut, Amit Kapila, Shi Yu, Vignesh C, Greg Nancarrow, Haiying Tang, Euler Taveira
Discussion: https://postgr.es/m/CAD21AoDeScrsHhLyEPYqN3sydg6PxAPVBboK=30xJfUVihNZDA@mail.gmail.com
2022-03-22 07:11:19 +05:30
Peter Eisentraut df4c3cbd8f Add parse_analyze_withcb()
This extracts code from pg_analyze_and_rewrite_withcb() into a
separate function that mirrors the existing
parse_analyze_fixedparams() and parse_analyze_varparams().

Reviewed-by: Nathan Bossart <bossartn@amazon.com>
Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
2022-03-09 11:08:16 +01:00
Peter Eisentraut 25751f54b8 Add pg_analyze_and_rewrite_varparams()
This new function extracts common code from PrepareQuery() and
exec_parse_message().  It is then exactly analogous to the existing
pg_analyze_and_rewrite_fixedparams() and
pg_analyze_and_rewrite_withcb().

To unify these two code paths, this makes PrepareQuery() now subject
to log_parser_stats.  Also, both paths now invoke
TRACE_POSTGRESQL_QUERY_REWRITE_START().  PrepareQuery() no longer
checks whether a utility statement was specified.  The grammar doesn't
allow that anyway, and exec_parse_message() supports it, so
restricting it doesn't seem necessary.

This also adds QueryEnvironment support to the *varparams functions,
for consistency with its cousins, even though it is not used right
now.

Reviewed-by: Nathan Bossart <bossartn@amazon.com>
Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
2022-03-07 08:13:30 +01:00
Peter Eisentraut 791b1b71da Parse/analyze function renaming
There are three parallel ways to call parse/analyze: with fixed
parameters, with variable parameters, and by supplying your own parser
callback.  Some of the involved functions were confusingly named and
made this API structure more confusing.  This patch renames some
functions to make this clearer:

parse_analyze() -> parse_analyze_fixedparams()
pg_analyze_and_rewrite() -> pg_analyze_and_rewrite_fixedparams()

(Otherwise one might think this variant doesn't accept parameters, but
in fact all three ways accept parameters.)

pg_analyze_and_rewrite_params() -> pg_analyze_and_rewrite_withcb()

(Before, and also when considering pg_analyze_and_rewrite(), one might
think this is the only way to pass parameters.  Moreover, the parser
callback doesn't necessarily need to parse only parameters, it's just
one of the things it could do.)

parse_fixed_parameters() -> setup_parse_fixed_parameters()
parse_variable_parameters() -> setup_parse_variable_parameters()

(These functions don't actually do any parsing, they just set up
callbacks to use during parsing later.)

This patch also adds some const decorations to the fixed-parameters
API, so the distinction from the variable-parameters API is more
clear.

Reviewed-by: Nathan Bossart <bossartn@amazon.com>
Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
2022-03-04 14:50:22 +01:00
Amit Kapila 52e4f0cd47 Allow specifying row filters for logical replication of tables.
This feature adds row filtering for publication tables. When a publication
is defined or modified, an optional WHERE clause can be specified. Rows
that don't satisfy this WHERE clause will be filtered out. This allows a
set of tables to be partially replicated. The row filter is per table. A
new row filter can be added simply by specifying a WHERE clause after the
table name. The WHERE clause must be enclosed by parentheses.

The row filter WHERE clause for a table added to a publication that
publishes UPDATE and/or DELETE operations must contain only columns that
are covered by REPLICA IDENTITY. The row filter WHERE clause for a table
added to a publication that publishes INSERT can use any column. If the
row filter evaluates to NULL, it is regarded as "false". The WHERE clause
only allows simple expressions that don't have user-defined functions,
user-defined operators, user-defined types, user-defined collations,
non-immutable built-in functions, or references to system columns. These
restrictions could be addressed in the future.

If you choose to do the initial table synchronization, only data that
satisfies the row filters is copied to the subscriber. If the subscription
has several publications in which a table has been published with
different WHERE clauses, rows that satisfy ANY of the expressions will be
copied. If a subscriber is a pre-15 version, the initial table
synchronization won't use row filters even if they are defined in the
publisher.

The row filters are applied before publishing the changes. If the
subscription has several publications in which the same table has been
published with different filters (for the same publish operation), those
expressions get OR'ed together so that rows satisfying any of the
expressions will be replicated.

This means all the other filters become redundant if (a) one of the
publications have no filter at all, (b) one of the publications was
created using FOR ALL TABLES, (c) one of the publications was created
using FOR ALL TABLES IN SCHEMA and the table belongs to that same schema.

If your publication contains a partitioned table, the publication
parameter publish_via_partition_root determines if it uses the partition's
row filter (if the parameter is false, the default) or the root
partitioned table's row filter.

Psql commands \dRp+ and \d <table-name> will display any row filters.

Author: Hou Zhijie, Euler Taveira, Peter Smith, Ajin Cherian
Reviewed-by: Greg Nancarrow, Haiying Tang, Amit Kapila, Tomas Vondra, Dilip Kumar, Vignesh C, Alvaro Herrera, Andres Freund, Wei Wang
Discussion: https://www.postgresql.org/message-id/flat/CAHE3wggb715X%2BmK_DitLXF25B%3DjE6xyNCH4YOwM860JR7HarGQ%40mail.gmail.com
2022-02-22 08:11:50 +05:30
Peter Eisentraut 2549f0661b Reject trailing junk after numeric literals
After this, the PostgreSQL lexers no longer accept numeric literals
with trailing non-digits, such as 123abc, which would be scanned as
two tokens: 123 and abc.  This is undocumented and surprising, and it
might also interfere with some extended numeric literal syntax being
contemplated for the future.

Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/b239564c-cad0-b23e-c57e-166d883cb97d@enterprisedb.com
2022-02-16 10:37:31 +01:00
Peter Eisentraut cfc7191dfe Move scanint8() to numutils.c
Move scanint8() to numutils.c and rename to pg_strtoint64().  We
already have a "16" and "32" version of that, and the code inside the
functions was aligned, so this move makes all three versions
consistent.  The API is also changed to no longer provide the errorOK
case.  Users that need the error checking can use strtoi64().

Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/b239564c-cad0-b23e-c57e-166d883cb97d@enterprisedb.com
2022-02-14 21:57:26 +01:00
Peter Eisentraut 37851a8b83 Database-level collation version tracking
This adds to database objects the same version tracking that collation
objects have.  There is a new pg_database column datcollversion that
stores the version, a new function
pg_database_collation_actual_version() to get the version from the
operating system, and a new subcommand ALTER DATABASE ... REFRESH
COLLATION VERSION.

This was not originally added together with pg_collation.collversion,
since originally version tracking was only supported for ICU, and ICU
on a database-level is not currently supported.  But we now have
version tracking for glibc (since PG13), FreeBSD (since PG14), and
Windows (since PG13), so this is useful to have now.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/f0ff3190-29a3-5b39-a179-fa32eee57db6%40enterprisedb.com
2022-02-14 08:27:26 +01:00
Peter Eisentraut 94aa7cc5f7 Add UNIQUE null treatment option
The SQL standard has been ambiguous about whether null values in
unique constraints should be considered equal or not.  Different
implementations have different behaviors.  In the SQL:202x draft, this
has been formalized by making this implementation-defined and adding
an option on unique constraint definitions UNIQUE [ NULLS [NOT]
DISTINCT ] to choose a behavior explicitly.

This patch adds this option to PostgreSQL.  The default behavior
remains UNIQUE NULLS DISTINCT.  Making this happen in the btree code
is pretty easy; most of the patch is just to carry the flag around to
all the places that need it.

The CREATE UNIQUE INDEX syntax extension is not from the standard,
it's my own invention.

I named all the internal flags, catalog columns, etc. in the negative
("nulls not distinct") so that the default PostgreSQL behavior is the
default if the flag is false.

Reviewed-by: Maxim Orlov <orlovmg@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/84e5ee1b-387e-9a54-c326-9082674bde78@enterprisedb.com
2022-02-03 11:48:21 +01:00
Tom Lane 8e2e0f7586 Fix failure to validate the result of select_common_type().
Although select_common_type() has a failure-return convention, an
apparent successful return just provides a type OID that *might* work
as a common supertype; we've not validated that the required casts
actually exist.  In the mainstream use-cases that doesn't matter,
because we'll proceed to invoke coerce_to_common_type() on each input,
which will fail appropriately if the proposed common type doesn't
actually work.  However, a few callers didn't read the (nonexistent)
fine print, and thought that if they got back a nonzero OID then the
coercions were sure to work.

This affects in particular the recently-added "anycompatible"
polymorphic types; we might think that a function/operator using
such types matches cases it really doesn't.  A likely end result
of that is unexpected "ambiguous operator" errors, as for example
in bug #17387 from James Inform.  Another, much older, case is that
the parser might try to transform an "x IN (list)" construct to
a ScalarArrayOpExpr even when the list elements don't actually have
a common supertype.

It doesn't seem desirable to add more checking to select_common_type
itself, as that'd just slow down the mainstream use-cases.  Instead,
write a separate function verify_common_type that performs the
missing checks, and add a call to that where necessary.  Likewise add
verify_common_type_from_oids to go with select_common_type_from_oids.

Back-patch to v13 where the "anycompatible" types came in.  (The
symptom complained of in bug #17387 doesn't appear till v14, but
that's just because we didn't get around to converting || to use
anycompatible till then.)  In principle the "x IN (list)" fix could
go back all the way, but I'm not currently convinced that it makes
much difference in real-world cases, so I won't bother for now.

Discussion: https://postgr.es/m/17387-5dfe54b988444963@postgresql.org
2022-01-29 11:41:18 -05:00
Peter Eisentraut 941460fcf7 Add Boolean node
Before, SQL-level boolean constants were represented by a string with
a cast, and internal Boolean values in DDL commands were usually
represented by Integer nodes.  This takes the place of both of these
uses, making the intent clearer and having some amount of type safety.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/8c1a2e37-c68d-703c-5a83-7a6077f4f997@enterprisedb.com
2022-01-17 10:38:23 +01:00
Peter Eisentraut c4cc2850f4 Rename value node fields
For the formerly-Value node types, rename the "val" field to a name
specific to the node type, namely "ival", "fval", "sval", and "bsval".
This makes some code clearer and catches mixups better.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/8c1a2e37-c68d-703c-5a83-7a6077f4f997@enterprisedb.com
2022-01-14 11:26:08 +01:00
Bruce Momjian 27b77ecf9f Update copyright for 2022
Backpatch-through: 10
2022-01-07 19:04:57 -05:00
Alvaro Herrera 9623d89996
Avoid using DefElemAction in AlterPublicationStmt
Create a new enum type for it.  This allows to add new values for future
functionality without disrupting unrelated uses of DefElem.

Discussion: https://postgr.es/m/202112302021.ca7ihogysgh3@alvherre.pgsql
2022-01-03 10:48:48 -03:00
Alvaro Herrera c9105dd366
Small cleanups related to PUBLICATION framework code
Discussion: https://postgr.es/m/202112302021.ca7ihogysgh3@alvherre.pgsql
2021-12-30 19:24:26 -03:00
Daniel Gustafsson e68570e388 Revert b2a459edf "Fix GRANTED BY support in REVOKE ROLE statements"
The reverted commit attempted to fix SQL specification compliance for
the cases which 6aaaa76bb left.  This however broke existing behavior
which takes precedence over spec compliance so revert. The introduced
tests are left after the revert since the codepath isn't well covered.
Per bug report 17346. Backpatch down to 14 where it was introduced.

Reported-by: Andrew Bille <andrewbille@gmail.com>
Discussion: https://postgr.es/m/17346-f72b28bd1a341060@postgresql.org
2021-12-30 13:23:47 +01:00
Tom Lane 9c356f4b2d Ensure casting to typmod -1 generates a RelabelType.
Fix the code changed by commit 5c056b0c2 so that we always generate
RelabelType, not something else, for a cast to unspecified typmod.
Otherwise planner optimizations might not happen.

It appears we missed this point because the previous experiments were
done on type numeric: the parser undesirably generates a call on the
numeric() length-coercion function, but then numeric_support()
optimizes that down to a RelabelType, so that everything seems fine.
It misbehaves for types that have a non-optimized length coercion
function, such as bpchar.

Per report from John Naylor.  Back-patch to all supported branches,
as the previous patch eventually was.  Unfortunately, that no longer
includes 9.6 ... we really shouldn't put this type of change into a
nearly-EOL branch.

Discussion: https://postgr.es/m/CAFBsxsEfbFHEkouc+FSj+3K1sHipLPbEC67L0SAe-9-da8QtYg@mail.gmail.com
2021-12-16 15:36:02 -05:00
Tom Lane bbc227e951 Always use ReleaseTupleDesc after lookup_rowtype_tupdesc et al.
The API spec for lookup_rowtype_tupdesc previously said you could use
either ReleaseTupleDesc or DecrTupleDescRefCount.  However, the latter
choice means the caller must be certain that the returned tupdesc is
refcounted.  I don't recall right now whether that was always true
when this spec was written, but it's certainly not always true since
we introduced shared record typcaches for parallel workers.  That means
that callers using DecrTupleDescRefCount are dependent on typcache
behavior details that they probably shouldn't be.  Hence, change the API
spec to say that you must call ReleaseTupleDesc, and fix the half-dozen
callers that weren't.

AFAICT this is just future-proofing, there's no live bug here.
So no back-patch.

Per gripe from Chapman Flack.

Discussion: https://postgr.es/m/61B901A4.1050808@anastigmatix.net
2021-12-15 18:58:20 -05:00
Peter Eisentraut d6f96ed94e Allow specifying column list for foreign key ON DELETE SET actions
Extend the foreign key ON DELETE actions SET NULL and SET DEFAULT by
allowing the specification of a column list, like

    CREATE TABLE posts (
        ...
        FOREIGN KEY (tenant_id, author_id) REFERENCES users ON DELETE SET NULL (author_id)
    );

If a column list is specified, only those columns are set to
null/default, instead of all the columns in the foreign-key
constraint.

This is useful for multitenant or sharded schemas, where the tenant or
shard ID is included in the primary key of all tables but shouldn't be
set to null.

Author: Paul Martinez <paulmtz@google.com>
Discussion: https://www.postgresql.org/message-id/flat/CACqFVBZQyMYJV=njbSMxf+rbDHpx=W=B7AEaMKn8dWn9OZJY7w@mail.gmail.com
2021-12-08 11:13:57 +01:00
Peter Eisentraut fb7f70112f Improve some comments in scanner files
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/b239564c-cad0-b23e-c57e-166d883cb97d@enterprisedb.com
2021-12-01 16:10:52 +01:00
Daniel Gustafsson b2a459edfe Fix GRANTED BY support in REVOKE ROLE statements
Commit 6aaaa76bb added support for the GRANTED BY clause in GRANT and
REVOKE statements, but missed adding support for checking the role in
the REVOKE ROLE case. Fix by checking that the parsed role matches the
CURRENT_ROLE/CURRENT_USER requirement, and also add some tests for it.
Backpatch to v14 where GRANTED BY support was introduced.

Discussion: https://postgr.es/m/B7F6699A-A984-4943-B9BF-CEB84C003527@yesql.se
Backpatch-through: 14
2021-11-26 14:02:01 +01:00
Amit Kapila b3812d0b9b Rename some enums to use TABLE instead of REL.
Commit 5a2832465f introduced some enums to represent all tables in schema
publications and used REL in their names. Use TABLE instead of REL in
those enums to avoid confusion with other objects like SEQUENCES that can
be part of a publication in the future.

In the passing, (a) Change one of the newly introduced error messages to
make it consistent for Create and Alter commands, (b) add missing alias in
one of the SQL Statements that is used to print publications associated
with the table.

Reported-by: Tomas Vondra, Peter Smith
Author: Vignesh C
Reviewed-by: Hou Zhijie, Peter Smith
Discussion: https://www.postgresql.org/message-id/CALDaNm0OANxuJ6RXqwZsM1MSY4s19nuH3734j4a72etDwvBETQ%40mail.gmail.com
2021-11-09 08:39:33 +05:30
Tom Lane 65c6cab136 Avoid O(N^2) behavior in SyncPostCheckpoint().
As in commits 6301c3ada and e9d9ba2a4, avoid doing repetitive
list_delete_first() operations, since that would be expensive when
there are many files waiting to be unlinked.  This is a slightly
larger change than in those cases.  We have to keep the list state
valid for calls to AbsorbSyncRequests(), so it's necessary to invent a
"canceled" field instead of immediately deleting PendingUnlinkEntry
entries.  Also, because we might not be able to process all the
entries, we need a new list primitive list_delete_first_n().

list_delete_first_n() is almost list_copy_tail(), but it modifies the
input List instead of making a new copy.  I found a couple of existing
uses of the latter that could profitably use the new function.  (There
might be more, but the other callers look like they probably shouldn't
overwrite the input List.)

As before, back-patch to v13.

Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com
2021-11-02 11:31:54 -04:00
Amit Kapila 5a2832465f Allow publishing the tables of schema.
A new option "FOR ALL TABLES IN SCHEMA" in Create/Alter Publication allows
one or more schemas to be specified, whose tables are selected by the
publisher for sending the data to the subscriber.

The new syntax allows specifying both the tables and schemas. For example:
CREATE PUBLICATION pub1 FOR TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;
OR
ALTER PUBLICATION pub1 ADD TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;

A new system table "pg_publication_namespace" has been added, to maintain
the schemas that the user wants to publish through the publication.
Modified the output plugin (pgoutput) to publish the changes if the
relation is part of schema publication.

Updates pg_dump to identify and dump schema publications. Updates the \d
family of commands to display schema publications and \dRp+ variant will
now display associated schemas if any.

Author: Vignesh C, Hou Zhijie, Amit Kapila
Syntax-Suggested-by: Tom Lane, Alvaro Herrera
Reviewed-by: Greg Nancarrow, Masahiko Sawada, Hou Zhijie, Amit Kapila, Haiying Tang, Ajin Cherian, Rahila Syed, Bharath Rupireddy, Mark Dilger
Tested-by: Haiying Tang
Discussion: https://www.postgresql.org/message-id/CALDaNm0OANxuJ6RXqwZsM1MSY4s19nuH3734j4a72etDwvBETQ@mail.gmail.com
2021-10-27 07:44:52 +05:30
Tom Lane 697dd1925f Remove bogus assertion in transformExpressionList().
I think when I added this assertion (in commit 8f889b108), I was only
thinking of the use of transformExpressionList at top level of INSERT
and VALUES.  But it's also called by transformRowExpr(), which can
certainly occur in an UPDATE targetlist, so it's inappropriate to
suppose that p_multiassign_exprs must be empty.  Besides, since the
input is not expected to contain ResTargets, there's no reason it
should contain MultiAssignRefs either.  Hence this code need not
be concerned about the state of p_multiassign_exprs, and we should
just drop the assertion.

Per bug #17236 from ocean_li_996.  It's been wrong for years,
so back-patch to all supported branches.

Discussion: https://postgr.es/m/17236-3210de9bcba1d7ca@postgresql.org
2021-10-19 11:35:15 -04:00
Alvaro Herrera c6bc655ee2
Error out if SKIP LOCKED and WITH TIES are both specified
Both bugs #16676[1] and #17141[2] illustrate that the combination of
SKIP LOCKED and FETCH FIRST WITH TIES break expectations when it comes
to rows returned to other sessions accessing the same row.  Since this
situation is detectable from the syntax and hard to fix otherwise,
forbid for now, with the potential to fix in the future.

[1] https://postgr.es/m/16676-fd62c3c835880da6@postgresql.org
[2] https://postgr.es/m/17141-913d78b9675aac8e@postgresql.org

Backpatch-through: 13, where WITH TIES was introduced
Author: David Christensen <david.christensen@crunchydata.com>
Discussion: https://postgr.es/m/CAOxo6XLPccCKru3xPMaYDpa+AXyPeWFs+SskrrL+HKwDjJnLhg@mail.gmail.com
2021-10-01 18:29:18 -03:00
Michael Paquier 070d2e19e4 Clarify use of "statistics objects" in the code
The code inconsistently used "statistic object" or "statistics" where
the correct term, as discussed, is actually "statistics object".  This
improves the state of the code to be more consistent.

While on it, fix an incorrect error message introduced in a4d75c8.  This
error should never happen, as the code states, but it would be
misleading.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20210924215827.GS831@telsasoft.com
Backpatch-through: 14
2021-09-29 15:29:38 +09:00
Peter Eisentraut 639a86e36a Remove Value node struct
The Value node struct is a weird construct.  It is its own node type,
but most of the time, it actually has a node type of Integer, Float,
String, or BitString.  As a consequence, the struct name and the node
type don't match most of the time, and so it has to be treated
specially a lot.  There doesn't seem to be any value in the special
construct.  There is very little code that wants to accept all Value
variants but nothing else (and even if it did, this doesn't provide
any convenient way to check it), and most code wants either just one
particular node type (usually String), or it accepts a broader set of
node types besides just Value.

This change removes the Value struct and node type and replaces them
by separate Integer, Float, String, and BitString node types that are
proper node types and structs of their own and behave mostly like
normal node types.

Also, this removes the T_Null node tag, which was previously also a
possible variant of Value but wasn't actually used outside of the
Value contained in A_Const.  Replace that by an isnull field in
A_Const.

Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/5ba6bc5b-3f95-04f2-2419-f8ddb4c046fb@enterprisedb.com
2021-09-09 08:36:53 +02:00
Peter Eisentraut a3d2b1bbe9 Disable anonymous record hash support except in special cases
Commit 01e658fa74 added hash support for row types.  This also added
support for hashing anonymous record types, using the same approach
that the type cache uses for comparison support for record types: It
just reports that it works, but it might fail at run time if a
component type doesn't actually support the operation.  We get away
with that for comparison because most types support that.  But some
types don't support hashing, so the current state can result in
failures at run time where the planner chooses hashing over sorting,
whereas that previously worked if only sorting was an option.

We do, however, want the record hashing support for path tracking in
recursive unions, and the SEARCH and CYCLE clauses built on that.  In
that case, hashing is the only plan option.  So enable that, this
commit implements the following approach: The type cache does not
report that hashing is available for the record type.  This undoes
that part of 01e658fa74.  Instead, callers that require hashing no
matter what can override that result themselves.  This patch only
touches the callers to make the aforementioned recursive query cases
work, namely the parse analysis of unions, as well as the hash_array()
function.

Reported-by: Sait Talha Nisanci <sait.nisanci@microsoft.com>
Bug: #17158
Discussion: https://www.postgresql.org/message-id/flat/17158-8a2ba823982537a4%40postgresql.org
2021-09-08 09:55:04 +02:00
Alvaro Herrera 0c6828fa98
Add PublicationTable and PublicationRelInfo structs
These encapsulate a relation when referred from replication DDL.
Currently they don't do anything useful (they're just wrappers around
RangeVar and Relation respectively) but in the future they'll be used to
carry column lists.

Extracted from a larger patch by Rahila Syed.

Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAH2L28vddB_NFdRVpuyRBJEBWjz4BSyTB=_ektNRH8NJ1jf95g@mail.gmail.com
2021-09-06 14:24:50 -03:00
Fujii Masao 78aa616be7 Fix typo in comments.
Author: Hou Zhijie
Discussion: https://postgr.es/m/OS0PR01MB5716E6A6535FDFDC5A1B004194CE9@OS0PR01MB5716.jpnprd01.prod.outlook.com
2021-09-06 17:03:40 +09:00
Fujii Masao 170aec63cd Avoid using ambiguous word "positive" in error message.
There are two identical error messages about valid value of modulus for
hash partition, in PostgreSQL source code. Commit 0e1275fb07 improved
only one of them so that ambiguous word "positive" was avoided there,
and forgot to improve the other. This commit improves the other.
Which would reduce translator burden.

Back-pach to v11 where the error message exists.

Author: Kyotaro Horiguchi
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com
2021-08-25 11:46:25 +09:00
Tom Lane 8d2d6ec770 Avoid trying to lock OLD/NEW in a rule with FOR UPDATE.
transformLockingClause neglected to exclude the pseudo-RTEs for
OLD/NEW when processing a rule's query.  This led to odd errors
or even crashes later on.  This bug is very ancient, but it's
not terribly surprising that nobody noticed, since the use-case
for SELECT FOR UPDATE in a non-view rule is somewhere between
thin and non-existent.  Still, crashing is not OK.

Per bug #17151 from Zhiyong Wu.  Thanks to Masahiko Sawada
for analysis of the problem.

Discussion: https://postgr.es/m/17151-c03a3e6e4ec9aadb@postgresql.org
2021-08-19 12:12:35 -04:00
Tom Lane 2313dda9d4 Fix check_agg_arguments' examination of aggregate FILTER clauses.
Recursion into the FILTER clause was mis-implemented, such that a
relevant Var or Aggref at the very top of the FILTER clause would
be ignored.  (Of course, that'd have to be a plain boolean Var or
boolean-returning aggregate.)  The consequence would be
mis-identification of the correct semantic level of the aggregate,
which could lead to not-per-spec query behavior.  If the FILTER
expression is an aggregate, this could also lead to failure to issue
an expected "aggregate function calls cannot be nested" error, which
would likely result in a core dump later on, since the planner and
executor aren't expecting such cases to appear.

The root cause is that commit b560ec1b0 blindly copied some code
that assumed it's recursing into a List, and thus didn't examine the
top-level node.  To forestall questions about why this call doesn't
look like the others, as well as possible future copy-and-paste
mistakes, let's change all three check_agg_arguments_walker calls in
check_agg_arguments, even though only the one for the filter clause
is really broken.

Per bug #17152 from Zhiyong Wu.  This has been wrong since we
implemented FILTER, so back-patch to all supported versions.
(Testing suggests that pre-v11 branches manage to avoid crashing
in the bad-Aggref case, thanks to "redundant" checks in ExecInitAgg.
But I'm not sure how thorough that protection is, and anyway the
wrong-behavior issue remains, so fix 9.6 and 10 too.)

Discussion: https://postgr.es/m/17152-c7f906cc1a88e61b@postgresql.org
2021-08-18 18:12:51 -04:00
Tom Lane 5c056b0c25 Don't elide casting to typmod -1.
Casting a value that's already of a type with a specific typmod
to an unspecified typmod doesn't do anything so far as run-time
behavior is concerned.  However, it really ought to change the
exposed type of the expression to match.  Up to now,
coerce_type_typmod hasn't bothered with that, which creates gotchas
in contexts such as recursive unions.  If for example one side of
the union is numeric(18,3), but it needs to be plain numeric to
match the other side, there's no direct way to express that.

This is easy enough to fix, by inserting a RelabelType to update the
exposed type of the expression.  However, it's a bit nervous-making
to change this behavior, because it's stood for a really long time.
(I strongly suspect that it's like this in part because the logic
pre-dates the introduction of RelabelType in 7.0.  The commit log
message for 57b30e8e2 is interesting reading here.)  As a compromise,
we'll sneak the change into 14beta3, and consider back-patching to
stable branches if no complaints emerge in the next three months.

Discussion: https://postgr.es/m/CABNQVagu3bZGqiTjb31a8D5Od3fUMs7Oh3gmZMQZVHZ=uWWWfQ@mail.gmail.com
2021-08-06 17:32:54 -04:00
Michael Paquier b0483263dd Add support for SET ACCESS METHOD in ALTER TABLE
The logic used to support a change of access method for a table is
similar to changes for tablespace or relation persistence, requiring a
table rewrite with an exclusive lock of the relation changed.  Table
rewrites done in ALTER TABLE already go through the table AM layer when
scanning tuples from the old relation and inserting them into the new
one, making this implementation straight-forward.

Note that partitioned tables are not supported as these have no access
methods defined.

Author: Justin Pryzby, Jeff Davis
Reviewed-by: Michael Paquier, Vignesh C
Discussion: https://postgr.es/m/20210228222530.GD20769@telsasoft.com
2021-07-28 10:10:44 +09:00
Tom Lane 336ea6e6ff Fix bugs in polymorphic-argument resolution for multiranges.
We failed to deal with an UNKNOWN-type input for
anycompatiblemultirange; that should throw an error indicating
that we don't know how to resolve the multirange type.

We also failed to infer the type of an anycompatiblerange output
from an anycompatiblemultirange input or vice versa.

Per bug #17066 from Alexander Lakhin.  Back-patch to v14
where multiranges were added.

Discussion: https://postgr.es/m/17066-16a37f6223a8470b@postgresql.org
2021-07-27 15:01:49 -04:00
Peter Eisentraut 2b00db4fb0 Use l*_node() family of functions where appropriate
Instead of castNode(…, lfoo(…))

Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/87eecahraj.fsf@wibble.ilmari.org
2021-07-19 08:20:24 +02:00
Dean Rasheed 2bfb50b3df Improve reporting of "conflicting or redundant options" errors.
When reporting "conflicting or redundant options" errors, try to
ensure that errposition() is used, to help the user identify the
offending option.

Formerly, errposition() was invoked in less than 60% of cases. This
patch raises that to over 90%, but there remain a few places where the
ParseState is not readily available. Using errdetail() might improve
the error in such cases, but that is left as a task for the future.

Additionally, since this error is thrown from over 100 places in the
codebase, introduce a dedicated function to throw it, reducing code
duplication.

Extracted from a slightly larger patch by Vignesh C. Reviewed by
Bharath Rupireddy, Alvaro Herrera, Dilip Kumar, Hou Zhijie, Peter
Smith, Daniel Gustafsson, Julien Rouhaud and me.

Discussion: https://postgr.es/m/CALDaNm33FFSS5tVyvmkoK2cCMuDVxcui=gFrjti9ROfynqSAGA@mail.gmail.com
2021-07-15 08:49:45 +01:00
Peter Eisentraut 9aa8268faa Fix some nonstandard C code indentation in grammar file 2021-07-15 00:11:00 +02:00
Peter Eisentraut 2ed532ee8c Improve error messages about mismatching relkind
Most error messages about a relkind that was not supported or
appropriate for the command was of the pattern

    "relation \"%s\" is not a table, foreign table, or materialized view"

This style can become verbose and tedious to maintain.  Moreover, it's
not very helpful: If I'm trying to create a comment on a TOAST table,
which is not supported, then the information that I could have created
a comment on a materialized view is pointless.

Instead, write the primary error message shorter and saying more
directly that what was attempted is not possible.  Then, in the detail
message, explain that the operation is not supported for the relkind
the object was.  To simplify that, add a new function
errdetail_relkind_not_supported() that does this.

In passing, make use of RELKIND_HAS_STORAGE() where appropriate,
instead of listing out the relkinds individually.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/dc35a398-37d0-75ce-07ea-1dd71d98f8ec@2ndquadrant.com
2021-07-08 09:44:51 +02:00
David Rowley 29f45e299e Use a hash table to speed up NOT IN(values)
Similar to 50e17ad28, which allowed hash tables to be used for IN clauses
with a set of constants, here we add the same feature for NOT IN clauses.

NOT IN evaluates the same as: WHERE a <> v1 AND a <> v2 AND a <> v3.
Obviously, if we're using a hash table we must be exactly equivalent to
that and return the same result taking into account that either side of
the condition could contain a NULL.  This requires a little bit of
special handling to make work with the hash table version.

When processing NOT IN, the ScalarArrayOpExpr's operator will be the <>
operator.  To be able to build and lookup a hash table we must use the
<>'s negator operator.  The planner checks if that exists and is hashable
and sets the relevant fields in ScalarArrayOpExpr to instruct the executor
to use hashing.

Author: David Rowley, James Coleman
Reviewed-by: James Coleman, Zhihong Yu
Discussion: https://postgr.es/m/CAApHDvoF1mum_FRk6D621edcB6KSHBi2+GAgWmioj5AhOu2vwQ@mail.gmail.com
2021-07-07 16:29:17 +12:00
David Rowley 63b1af9437 Cleanup some aggregate code in the executor
Here we alter the code that calls build_pertrans_for_aggref() so that the
function no longer needs to special-case whether it's dealing with an
aggtransfn or an aggcombinefn.  This allows us to reuse the
build_aggregate_transfn_expr() function and just get rid of the
build_aggregate_combinefn_expr() completely.

All of the special case code that was in build_pertrans_for_aggref() has
been moved up to the calling functions.

This saves about a dozen lines of code in nodeAgg.c and a few dozen more
in parse_agg.c

Also, rename a few variables in nodeAgg.c to try to make it more clear
that we're working with either a aggtransfn or an aggcombinefn.  Some of
the old names would have you believe that we were always working with an
aggtransfn.

Discussion: https://postgr.es/m/CAApHDvptMQ9FmF0D67zC_w88yVnoNVR2+kkOQGUrCmdxWxLULQ@mail.gmail.com
2021-07-04 18:47:31 +12:00
David Rowley 3788c66788 Improve various places that double the size of a buffer
Several places were performing a tight loop to determine the first power
of 2 number that's > or >= the required memory.  Instead of using a loop
for that, we can use pg_nextpower2_32 or pg_nextpower2_64.  When we need a
power of 2 number equal to or greater than a given amount, we just pass
the amount to the nextpower2 function.  When we need a power of 2 greater
than the amount, we just pass the amount + 1.

Additionally, in tsearch there were a couple of locations that were
performing a while loop when a simple "if" would have done.  In both of
these locations only 1 item is being added, so the loop could only have
ever iterated once.  Changing the loop into an if statement makes the code
very slightly more optimal as the condition is checked once rather than
twice.

There are quite a few remaining locations that increase the size of the
buffer in the following form:

  while (reqsize >= buflen)
  {
     buflen *= 2;
     buf = repalloc(buf, buflen);
  }

These are not touched in this commit.  repalloc will error out for sizes
larger than MaxAllocSize.  Changing these to use pg_nextpower2_32 would
remove the chance of that error being raised.  It's unclear from the code
if the sizes could ever become that large, so err on the side of caution.

Discussion: https://postgr.es/m/CAApHDvp=tns7RL4PH0ZR0M+M-YFLquK7218x=0B_zO+DbOma+w@mail.gmail.com
Reviewed-by: Zhihong Yu
2021-07-01 15:29:06 +12:00
David Rowley 8d29d45d9b Fix assert failure in expand_grouping_sets
linitial_node() fails in assert enabled builds if the given pointer is
not of the specified type.  Here the type is IntList.  The code thought
it should be expecting List, but it was wrong.

In the existing tests which run this code the initial list element is
always NIL.  Since linitial_node() allows NULL, we didn't trigger any
assert failures in the existing regression tests.

There is still some discussion as to whether we need a few more tests in
this area, but for now, since beta2 is looming, fix the bug first.

Bug: #17067
Discussion: https://postgr.es/m/17067-665d50fa321f79e0@postgresql.org
Reported-by: Yaoguang Chen
2021-06-21 23:11:23 +12:00
Tom Lane 7c337b6b52 Centralize the logic for protective copying of utility statements.
In the "simple Query" code path, it's fine for parse analysis or
execution of a utility statement to scribble on the statement's node
tree, since that'll just be thrown away afterwards.  However it's
not fine if the node tree is in the plan cache, as then it'd be
corrupted for subsequent executions.  Up to now we've dealt with
that by having individual utility-statement functions apply
copyObject() if they were going to modify the tree.  But that's
prone to errors of omission.  Bug #17053 from Charles Samborski
shows that CREATE/ALTER DOMAIN didn't get this memo, and can
crash if executed repeatedly from plan cache.

In the back branches, we'll just apply a narrow band-aid for that,
but in HEAD it seems prudent to have a more principled fix that
will close off the possibility of other similar bugs in future.
Hence, let's hoist the responsibility for doing copyObject up into
ProcessUtility from its children, thus ensuring that it happens for
all utility statement types.

Also, modify ProcessUtility's API so that its callers can tell it
whether a copy step is necessary.  It turns out that in all cases,
the immediate caller knows whether the node tree is transient, so
this doesn't involve a huge amount of code thrashing.  In this way,
while we lose a little bit in the execute-from-cache code path due
to sometimes copying node trees that wouldn't be mutated anyway,
we gain something in the simple-Query code path by not copying
throwaway node trees.  Statements that are complex enough to be
expensive to copy are almost certainly ones that would have to be
copied anyway, so the loss in the cache code path shouldn't be much.

(Note that this whole problem applies only to utility statements.
Optimizable statements don't have the issue because we long ago made
the executor treat Plan trees as read-only.  Perhaps someday we will
make utility statement execution act likewise, but I'm not holding
my breath.)

Discussion: https://postgr.es/m/931771.1623893989@sss.pgh.pa.us
Discussion: https://postgr.es/m/17053-3ca3f501bbc212b4@postgresql.org
2021-06-18 11:22:58 -04:00
Noah Misch 13a1ca160d Change position of field "transformed" in struct CreateStatsStmt.
Resolve the disagreement with nodes/*funcs.c field order in favor of the
latter, which is better-aligned with the IndexStmt field order.  This
field is new in v14.

Discussion: https://postgr.es/m/20210611045546.GA573364@rfd.leadboat.com
2021-06-10 21:56:14 -07:00
Tom Lane e56bce5d43 Reconsider the handling of procedure OUT parameters.
Commit 2453ea142 redefined pg_proc.proargtypes to include the types of
OUT parameters, for procedures only.  While that had some advantages
for implementing the SQL-spec behavior of DROP PROCEDURE, it was pretty
disastrous from a number of other perspectives.  Notably, since the
primary key of pg_proc is name + proargtypes, this made it possible to
have multiple procedures with identical names + input arguments and
differing output argument types.  That would make it impossible to call
any one of the procedures by writing just NULL (or "?", or any other
data-type-free notation) for the output argument(s).  The change also
seems likely to cause grave confusion for client applications that
examine pg_proc and expect the traditional definition of proargtypes.

Hence, revert the definition of proargtypes to what it was, and
undo a number of complications that had been added to support that.

To support the SQL-spec behavior of DROP PROCEDURE, when there are
no argmode markers in the command's parameter list, we perform the
lookup both ways (that is, matching against both proargtypes and
proallargtypes), succeeding if we get just one unique match.
In principle this could result in ambiguous-function failures
that would not happen when using only one of the two rules.
However, overloading of procedure names is thought to be a pretty
rare usage, so this shouldn't cause many problems in practice.
Postgres-specific code such as pg_dump can defend against any
possibility of such failures by being careful to specify argmodes
for all procedure arguments.

This also fixes a few other bugs in the area of CALL statements
with named parameters, and improves the documentation a little.

catversion bump forced because the representation of procedures
with OUT arguments changes.

Discussion: https://postgr.es/m/3742981.1621533210@sss.pgh.pa.us
2021-06-10 17:11:36 -04:00
Tom Lane bfeede9fa4 Don't crash on empty statements in SQL-standard function bodies.
gram.y should discard NULL pointers (empty statements) when
assembling a routine_body_stmt_list, as it does for other
sorts of statement lists.

Julien Rouhaud and Tom Lane, per report from Noah Misch.

Discussion: https://postgr.es/m/20210606044418.GA297923@rfd.leadboat.com
2021-06-08 11:59:34 -04:00
Tom Lane a65e9f3f14 Fix inconsistent equalfuncs.c behavior for FuncCall.funcformat.
Other equalfuncs.c checks on CoercionForm fields use
COMPARE_COERCIONFORM_FIELD (which makes them no-ops),
but commit 40c24bfef neglected to make _equalFuncCall
do likewise.  Fix that.

This is only strictly correct if FuncCall.funcformat has
no semantic effect, instead just determining ruleutils.c
display formatting.  40c24bfef added a couple of checks
in parse analysis that could break that rule; but on closer
inspection, they're redundant, so just take them out again.

Per report from Noah Misch.

Discussion: https://postgr.es/m/20210606063331.GC297923@rfd.leadboat.com
2021-06-06 15:46:58 -04:00
Tom Lane 1103033aed Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.
This case should be disallowed, just as FOR UPDATE with a plain
GROUP BY is disallowed; FOR UPDATE only makes sense when each row
of the query result can be identified with a single table row.
However, we missed teaching CheckSelectLocking() to check
groupingSets as well as groupClause, so that it would allow
degenerate grouping sets.  That resulted in a bad plan and
a null-pointer dereference in the executor.

Looking around for other instances of the same bug, the only one
I found was in examine_simple_variable().  That'd just lead to
silly estimates, but it should be fixed too.

Per private report from Yaoguang Chen.
Back-patch to all supported branches.
2021-06-01 11:12:56 -04:00
Tom Lane e6241d8e03 Rethink definition of pg_attribute.attcompression.
Redefine '\0' (InvalidCompressionMethod) as meaning "if we need to
compress, use the current setting of default_toast_compression".
This allows '\0' to be a suitable default choice regardless of
datatype, greatly simplifying code paths that initialize tupledescs
and the like.  It seems like a more user-friendly approach as well,
because now the default compression choice doesn't migrate into table
definitions, meaning that changing default_toast_compression is
usually sufficient to flip an installation's behavior; one needn't
tediously issue per-column ALTER SET COMPRESSION commands.

Along the way, fix a few minor bugs and documentation issues
with the per-column-compression feature.  Adopt more robust
APIs for SetIndexStorageProperties and GetAttributeCompression.

Bump catversion because typical contents of attcompression will now
be different.  We could get away without doing that, but it seems
better to ensure v14 installations all agree on this.  (We already
forced initdb for beta2, anyway.)

Discussion: https://postgr.es/m/626613.1621787110@sss.pgh.pa.us
2021-05-27 13:24:27 -04:00
Alvaro Herrera cafde58b33
Allow compute_query_id to be set to 'auto' and make it default
Allowing only on/off meant that all either all existing configuration
guides would become obsolete if we disabled it by default, or that we
would have to accept a performance loss in the default config if we
enabled it by default.  By allowing 'auto' as a middle ground, the
performance cost is only paid by those who enable pg_stat_statements and
similar modules.

I only edited the release notes to comment-out a paragraph that is now
factually wrong; further edits are probably needed to describe the
related change in more detail.

Author: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20210513002623.eugftm4nk2lvvks3@nol
2021-05-15 14:13:09 -04:00
Tom Lane def5b065ff Initial pgindent and pgperltidy run for v14.
Also "make reformat-dat-files".

The only change worthy of note is that pgindent messed up the formatting
of launcher.c's struct LogicalRepWorkerId, which led me to notice that
that struct wasn't used at all anymore, so I just took it out.
2021-05-12 13:14:10 -04:00
Peter Eisentraut ec6e70c79f Refactor some error messages for easier translation 2021-05-12 07:42:51 +02:00
Peter Eisentraut 6d177e2813 Fix typo 2021-05-11 09:06:49 +02:00
Tomas Vondra 93f9af1387 Fix typos in comments about extended statistics
Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20210505210947.GA27406%40telsasoft.com
2021-05-07 14:40:36 +02:00
Thomas Munro ec48314708 Revert per-index collation version tracking feature.
Design problems were discovered in the handling of composite types and
record types that would cause some relevant versions not to be recorded.
Misgivings were also expressed about the use of the pg_depend catalog
for this purpose.  We're out of time for this release so we'll revert
and try again.

Commits reverted:

1bf946bd: Doc: Document known problem with Windows collation versions.
cf002008: Remove no-longer-relevant test case.
ef387bed: Fix bogus collation-version-recording logic.
0fb0a050: Hide internal error for pg_collation_actual_version(<bad OID>).
ff942057: Suppress "warning: variable 'collcollate' set but not used".
d50e3b1f: Fix assertion in collation version lookup.
f24b1569: Rethink extraction of collation dependencies.
257836a7: Track collation versions for indexes.
cd6f479e: Add pg_depend.refobjversion.
7d1297df: Remove pg_collation.collversion.

Discussion: https://postgr.es/m/CA%2BhUKGLhj5t1fcjqAu8iD9B3ixJtsTNqyCCD4V0aTO9kAKAjjA%40mail.gmail.com
2021-05-07 21:10:11 +12:00
Alvaro Herrera a288d94c91
Remove redundant variable
Author: Amul Sul <sulamul@gmail.com>
Reviewed-by: Jeevan Ladhe <jeevan.ladhe@enterprisedb.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/CAAJ_b94HaNcrPVREUuB9-qUn2uB+gfcoX3FG_Vx0S6aFse+yhw@mail.gmail.com
2021-05-06 17:28:36 -04:00
Fujii Masao 3f20d5f370 Reorder COMPRESSION option in gram.y and parsenodes.h into alphabetical order.
Commit bbe0a81db6 introduced "INCLUDING COMPRESSION" option
in CREATE TABLE command, but previously TableLikeOption in gram.y and
parsenodes.h didn't classify this new option in alphabetical order
with the rest.

Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/YHerAixOhfR1ryXa@paquier.xyz
2021-04-23 19:10:24 +09:00
Bruce Momjian 9660834dd8 adjust query id feature to use pg_stat_activity.query_id
Previously, it was pg_stat_activity.queryid to match the
pg_stat_statements queryid column.  This is an adjustment to patch
4f0b0966c8.  This also adjusts some of the internal function calls to
match.  Catversion bumped.

Reported-by: Álvaro Herrera, Julien Rouhaud

Discussion: https://postgr.es/m/20210408032704.GA7498@alvherre.pgsql
2021-04-20 12:22:26 -04:00
Tom Lane 6c0373ab77 Allow table-qualified variable names in ON CONFLICT ... WHERE.
Previously you could only use unqualified variable names here.
While that's not a functional deficiency, since only the target
table can be referenced, it's a surprising inconsistency with the
rules for partial-index predicates, on which this syntax is
supposedly modeled.

The fix for that is no harder than passing addToRelNameSpace = true
to addNSItemToQuery.  However, it's really pretty bogus for
transformOnConflictArbiter and transformOnConflictClause to be
messing with the namespace item for the target table at all.
It's not theirs to manage, it results in duplicative creations of
namespace items, and transformOnConflictClause wasn't even doing
it quite correctly (that coding resulted in two nsitems for the
target table, since it hadn't cleaned out the existing one).
Hence, make transformInsertStmt responsible for setting up the
target nsitem once for both these clauses and RETURNING.

Also, arrange for ON CONFLICT ... UPDATE's "excluded" pseudo-relation
to be added to the rangetable before we run transformOnConflictArbiter.
This produces a more helpful HINT if someone writes "excluded.col"
in the arbiter expression.

Per bug #16958 from Lukas Eder.  Although I agree this is a bug,
the consequences are hardly severe, so no back-patch.

Discussion: https://postgr.es/m/16958-963f638020de271c@postgresql.org
2021-04-13 15:39:41 -04:00
Tom Lane c402b02b9f Fix old bug with coercing the result of a COLLATE expression.
There are hacks in parse_coerce.c to push down a requested coercion
to below any CollateExpr that may appear.  However, we did that even
if the requested data type is non-collatable, leading to an invalid
expression tree in which CollateExpr is applied to a non-collatable
type.  The fix is just to drop the CollateExpr altogether, reasoning
that it's useless.

This bug is ten years old, dating to the original addition of
COLLATE support.  The lack of field complaints suggests that there
aren't a lot of user-visible consequences.  We noticed the problem
because it would trigger an assertion in DefineVirtualRelation if
the invalid structure appears as an output column of a view; however,
in a non-assert build, you don't see a crash just a (subtly incorrect)
complaint about applying collation to a non-collatable type.  I found
that by putting the incorrect structure further down in a view, I could
make a view definition that would fail dump/reload, per the added
regression test case.  But CollateExpr doesn't do anything at run-time,
so this likely doesn't lead to any really exciting consequences.

Per report from Yulin Pei.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/HK0PR01MB22744393C474D503E16C8509F4709@HK0PR01MB2274.apcprd01.prod.exchangelabs.com
2021-04-12 14:37:49 -04:00
David Rowley 50e17ad281 Speedup ScalarArrayOpExpr evaluation
ScalarArrayOpExprs with "useOr=true" and a set of Consts on the righthand
side have traditionally been evaluated by using a linear search over the
array.  When these arrays contain large numbers of elements then this
linear search could become a significant part of execution time.

Here we add a new method of evaluating ScalarArrayOpExpr expressions to
allow them to be evaluated by first building a hash table containing each
element, then on subsequent evaluations, we just probe that hash table to
determine if there is a match.

The planner is in charge of determining when this optimization is possible
and it enables it by setting hashfuncid in the ScalarArrayOpExpr.  The
executor will only perform the hash table evaluation when the hashfuncid
is set.

This means that not all cases are optimized. For example CHECK constraints
containing an IN clause won't go through the planner, so won't get the
hashfuncid set.  We could maybe do something about that at some later
date.  The reason we're not doing it now is from fear that we may slow
down cases where the expression is evaluated only once.  Those cases can
be common, for example, a single row INSERT to a table with a CHECK
constraint containing an IN clause.

In the planner, we enable this when there are suitable hash functions for
the ScalarArrayOpExpr's operator and only when there is at least
MIN_ARRAY_SIZE_FOR_HASHED_SAOP elements in the array.  The threshold is
currently set to 9.

Author: James Coleman, David Rowley
Reviewed-by: David Rowley, Tomas Vondra, Heikki Linnakangas
Discussion: https://postgr.es/m/CAAaqYe8x62+=wn0zvNKCj55tPpg-JBHzhZFFc6ANovdqFw7-dA@mail.gmail.com
2021-04-08 23:51:22 +12:00
Peter Eisentraut e717a9a18b SQL-standard function body
This adds support for writing CREATE FUNCTION and CREATE PROCEDURE
statements for language SQL with a function body that conforms to the
SQL standard and is portable to other implementations.

Instead of the PostgreSQL-specific AS $$ string literal $$ syntax,
this allows writing out the SQL statements making up the body
unquoted, either as a single statement:

    CREATE FUNCTION add(a integer, b integer) RETURNS integer
        LANGUAGE SQL
        RETURN a + b;

or as a block

    CREATE PROCEDURE insert_data(a integer, b integer)
    LANGUAGE SQL
    BEGIN ATOMIC
      INSERT INTO tbl VALUES (a);
      INSERT INTO tbl VALUES (b);
    END;

The function body is parsed at function definition time and stored as
expression nodes in a new pg_proc column prosqlbody.  So at run time,
no further parsing is required.

However, this form does not support polymorphic arguments, because
there is no more parse analysis done at call time.

Dependencies between the function and the objects it uses are fully
tracked.

A new RETURN statement is introduced.  This can only be used inside
function bodies.  Internally, it is treated much like a SELECT
statement.

psql needs some new intelligence to keep track of function body
boundaries so that it doesn't send off statements when it sees
semicolons that are inside a function body.

Tested-by: Jaime Casanova <jcasanov@systemguards.com.ec>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/1c11f1eb-f00c-43b7-799d-2d44132c02d7@2ndquadrant.com
2021-04-07 21:47:55 +02:00
Bruce Momjian 4f0b0966c8 Make use of in-core query id added by commit 5fd9dfa5f5
Use the in-core query id computation for pg_stat_activity,
log_line_prefix, and EXPLAIN VERBOSE.

Similar to other fields in pg_stat_activity, only the queryid from the
top level statements are exposed, and if the backends status isn't
active then the queryid from the last executed statements is displayed.

Add a %Q placeholder to include the queryid in log_line_prefix, which
will also only expose top level statements.

For EXPLAIN VERBOSE, if a query identifier has been computed, either by
enabling compute_query_id or using a third-party module, display it.

Bump catalog version.

Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol

Author: Julien Rouhaud

Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
2021-04-07 14:04:06 -04:00
Bruce Momjian 5fd9dfa5f5 Move pg_stat_statements query jumbling to core.
Add compute_query_id GUC to control whether a query identifier should be
computed by the core (off by default).  It's thefore now possible to
disable core queryid computation and use pg_stat_statements with a
different algorithm to compute the query identifier by using a
third-party module.

To ensure that a single source of query identifier can be used and is
well defined, modules that calculate a query identifier should throw an
error if compute_query_id specified to compute a query id and if a query
idenfitier was already calculated.

Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol

Author: Julien Rouhaud

Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
2021-04-07 13:06:56 -04:00
Peter Eisentraut dd13ad9d39 Fix use of cursor sensitivity terminology
Documentation and comments in code and tests have been using the terms
sensitive/insensitive cursor incorrectly relative to the SQL standard.
(Cursor sensitivity is only relevant for changes made in the same
transaction as the cursor, not for concurrent changes in other
sessions.)  Moreover, some of the behavior of PostgreSQL is incorrect
according to the SQL standard, confusing the issue further.  (WHERE
CURRENT OF changes are not visible in insensitive cursors, but they
should be.)

This change corrects the terminology and removes the claim that
sensitive cursors are supported.  It also adds a test case that checks
the insensitive behavior in a "correct" way, using a change command
not using WHERE CURRENT OF.  Finally, it adds the ASENSITIVE cursor
option to select the default asensitive behavior, per SQL standard.

There are no changes to cursor behavior in this patch.

Discussion: https://www.postgresql.org/message-id/flat/96ee8b30-9889-9e1b-b053-90e10c050e85%40enterprisedb.com
2021-04-07 08:05:55 +02:00
Tom Lane 091e22b2e6 Clean up treatment of missing default and CHECK-constraint records.
Andrew Gierth reported that it's possible to crash the backend if no
pg_attrdef record is found to match an attribute that has atthasdef set.
AttrDefaultFetch warns about this situation, but then leaves behind
a relation tupdesc that has null "adbin" pointer(s), which most places
don't guard against.

We considered promoting the warning to an error, but throwing errors
during relcache load is pretty drastic: it effectively locks one out
of using the relation at all.  What seems better is to leave the
load-time behavior as a warning, but then throw an error in any code
path that wants to use a default and can't find it.  This confines
the error to a subset of INSERT/UPDATE operations on the table, and
in particular will at least allow a pg_dump to succeed.

Also, we should fix AttrDefaultFetch to not leave any null pointers
in the tupdesc, because that just creates an untested bug hazard.

While at it, apply the same philosophy of "warn at load, throw error
only upon use of the known-missing info" to CHECK constraints.
CheckConstraintFetch is very nearly the same logic as AttrDefaultFetch,
but for reasons lost in the mists of time, it was throwing ERROR for
the same cases that AttrDefaultFetch treats as WARNING.  Make the two
functions more nearly alike.

In passing, get rid of potentially-O(N^2) loops in equalTupleDesc
by making AttrDefaultFetch sort the entries after fetching them,
so that equalTupleDesc can assume that entries in two equal tupdescs
must be in matching order.  (CheckConstraintFetch already was sorting
CHECK constraints, but equalTupleDesc hadn't been told about it.)

There's some argument for back-patching this, but with such a small
number of field reports, I'm content to fix it in HEAD.

Discussion: https://postgr.es/m/87pmzaq4gx.fsf@news-spur.riddles.org.uk
2021-04-06 10:34:39 -04:00
Peter Eisentraut 82ed7748b7 ALTER SUBSCRIPTION ... ADD/DROP PUBLICATION
At present, if we want to update publications in a subscription, we
can use SET PUBLICATION.  However, it requires supplying all
publications that exists and the new publications.  If we want to add
new publications, it's inconvenient.  The new syntax only supplies the
new publications.  When the refresh is true, it only refreshes the new
publications.

Author: Japin Li <japinli@hotmail.com>
Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/MEYP282MB166939D0D6C480B7FBE7EFFBB6BC0@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
2021-04-06 11:49:51 +02:00
Peter Eisentraut a2da77cdb4 Change return type of EXTRACT to numeric
The previous implementation of EXTRACT mapped internally to
date_part(), which returned type double precision (since it was
implemented long before the numeric type existed).  This can lead to
imprecise output in some cases, so returning numeric would be
preferrable.  Changing the return type of an existing function is a
bit risky, so instead we do the following:  We implement a new set of
functions, which are now called "extract", in parallel to the existing
date_part functions.  They work the same way internally but use
numeric instead of float8.  The EXTRACT construct is now mapped by the
parser to these new extract functions.  That way, dumps of views
etc. from old versions (which would use date_part) continue to work
unchanged, but new uses will map to the new extract functions.

Additionally, the reverse compilation of EXTRACT now reproduces the
original syntax, using the new mechanism introduced in
40c24bfef9.

The following minor changes of behavior result from the new
implementation:

- The column name from an isolated EXTRACT call is now "extract"
  instead of "date_part".

- Extract from date now rejects inappropriate field names such as
  HOUR.  It was previously mapped internally to extract from
  timestamp, so it would silently accept everything appropriate for
  timestamp.

- Return values when extracting fields with possibly fractional
  values, such as second and epoch, now have the full scale that the
  value has internally (so, for example, '1.000000' instead of just
  '1').

Reported-by: Petr Fedorov <petr.fedorov@phystech.edu>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/42b73d2d-da12-ba9f-570a-420e0cce19d9@phystech.edu
2021-04-06 07:20:42 +02:00
Peter Eisentraut 055fee7eb4 Allow an alias to be attached to a JOIN ... USING
This allows something like

    SELECT ... FROM t1 JOIN t2 USING (a, b, c) AS x

where x has the columns a, b, c and unlike a regular alias it does not
hide the range variables of the tables being joined t1 and t2.

Per SQL:2016 feature F404 "Range variable for common column names".

Reviewed-by: Vik Fearing <vik.fearing@2ndquadrant.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/454638cf-d563-ab76-a585-2564428062af@2ndquadrant.com
2021-03-31 17:10:50 +02:00
Peter Eisentraut 66392d3965 Add p_names field to ParseNamespaceItem
ParseNamespaceItem had a wired-in assumption that p_rte->eref
describes the table and column aliases exposed by the nsitem.  This
relaxes this by creating a separate p_names field in an nsitem.  This
is mainly preparation for a patch for JOIN USING aliases, but it saves
one indirection in common code paths, so it's possibly a win on its
own.

Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/785329.1616455091@sss.pgh.pa.us
2021-03-31 10:52:37 +02:00
Peter Eisentraut 91c5a8caaa Add errhint_plural() function and make use of it
Similar to existing errmsg_plural() and errdetail_plural().  Some
errhint() calls hadn't received the proper plural treatment yet.
2021-03-31 09:16:25 +02:00
Tomas Vondra a4d75c86bf Extended statistics on expressions
Allow defining extended statistics on expressions, not just just on
simple column references.  With this commit, expressions are supported
by all existing extended statistics kinds, improving the same types of
estimates. A simple example may look like this:

  CREATE TABLE t (a int);
  CREATE STATISTICS s ON mod(a,10), mod(a,20) FROM t;
  ANALYZE t;

The collected statistics are useful e.g. to estimate queries with those
expressions in WHERE or GROUP BY clauses:

  SELECT * FROM t WHERE mod(a,10) = 0 AND mod(a,20) = 0;

  SELECT 1 FROM t GROUP BY mod(a,10), mod(a,20);

This introduces new internal statistics kind 'e' (expressions) which is
built automatically when the statistics object definition includes any
expressions. This represents single-expression statistics, as if there
was an expression index (but without the index maintenance overhead).
The statistics is stored in pg_statistics_ext_data as an array of
composite types, which is possible thanks to 79f6a942bd.

CREATE STATISTICS allows building statistics on a single expression, in
which case in which case it's not possible to specify statistics kinds.

A new system view pg_stats_ext_exprs can be used to display expression
statistics, similarly to pg_stats and pg_stats_ext views.

ALTER TABLE ... ALTER COLUMN ... TYPE now treats indexes the same way it
treats indexes, i.e. it drops and recreates the statistics. This means
all statistics are reset, and we no longer try to preserve at least the
functional dependencies. This should not be a major issue in practice,
as the functional dependencies actually rely on per-column statistics,
which were always reset anyway.

Author: Tomas Vondra
Reviewed-by: Justin Pryzby, Dean Rasheed, Zhihong Yu
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
2021-03-27 00:01:11 +01:00
Alvaro Herrera 71f4c8c6f7
ALTER TABLE ... DETACH PARTITION ... CONCURRENTLY
Allow a partition be detached from its partitioned table without
blocking concurrent queries, by running in two transactions and only
requiring ShareUpdateExclusive in the partitioned table.

Because it runs in two transactions, it cannot be used in a transaction
block.  This is the main reason to use dedicated syntax: so that users
can choose to use the original mode if they need it.  But also, it
doesn't work when a default partition exists (because an exclusive lock
would still need to be obtained on it, in order to change its partition
constraint.)

In case the second transaction is cancelled or a crash occurs, there's
ALTER TABLE .. DETACH PARTITION .. FINALIZE, which executes the final
steps.

The main trick to make this work is the addition of column
pg_inherits.inhdetachpending, initially false; can only be set true in
the first part of this command.  Once that is committed, concurrent
transactions that use a PartitionDirectory will include or ignore
partitions so marked: in optimizer they are ignored if the row is marked
committed for the snapshot; in executor they are always included.  As a
result, and because of the way PartitionDirectory caches partition
descriptors, queries that were planned before the detach will see the
rows in the detached partition and queries that are planned after the
detach, won't.

A CHECK constraint is created that duplicates the partition constraint.
This is probably not strictly necessary, and some users will prefer to
remove it afterwards, but if the partition is re-attached to a
partitioned table, the constraint needn't be rechecked.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20200803234854.GA24158@alvherre.pgsql
2021-03-25 18:00:28 -03:00
Peter Eisentraut f2c7ce64ae Trim some extra whitespace in parser file 2021-03-25 10:17:52 +01:00
Peter Eisentraut 91d1f2d302 Rename a parse node to be more general
A WHERE clause will be used for row filtering in logical replication.
We already have a similar node: 'WHERE (condition here)'.  Let's
rename the node to a generic name and use it for row filtering too.

Author: Euler Taveira <euler.taveira@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHE3wggb715X+mK_DitLXF25B=jE6xyNCH4YOwM860JR7HarGQ@mail.gmail.com
2021-03-25 10:06:32 +01:00
Tomas Vondra b822ae13ea Use lfirst_int in cmp_list_len_contents_asc
The function added in be45be9c33 is comparing integer lists (IntList) by
length and contents, but there were two bugs.  Firstly, it used intVal()
to extract the value, but that's for Value nodes, not for extracting int
values from IntList.  Secondly, it called it directly on the ListCell,
without doing lfirst().  So just do lfirst_int() instead.

Interestingly enough, this did not cause any crashes on the buildfarm,
but valgrind rightfully complained about it.

Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org
2021-03-20 00:04:25 +01:00
Robert Haas bbe0a81db6 Allow configurable LZ4 TOAST compression.
There is now a per-column COMPRESSION option which can be set to pglz
(the default, and the only option in up until now) or lz4. Or, if you
like, you can set the new default_toast_compression GUC to lz4, and
then that will be the default for new table columns for which no value
is specified. We don't have lz4 support in the PostgreSQL code, so
to use lz4 compression, PostgreSQL must be built --with-lz4.

In general, TOAST compression means compression of individual column
values, not the whole tuple, and those values can either be compressed
inline within the tuple or compressed and then stored externally in
the TOAST table, so those properties also apply to this feature.

Prior to this commit, a TOAST pointer has two unused bits as part of
the va_extsize field, and a compessed datum has two unused bits as
part of the va_rawsize field. These bits are unused because the length
of a varlena is limited to 1GB; we now use them to indicate the
compression type that was used. This means we only have bit space for
2 more built-in compresison types, but we could work around that
problem, if necessary, by introducing a new vartag_external value for
any further types we end up wanting to add. Hopefully, it won't be
too important to offer a wide selection of algorithms here, since
each one we add not only takes more coding but also adds a build
dependency for every packager. Nevertheless, it seems worth doing
at least this much, because LZ4 gets better compression than PGLZ
with less CPU usage.

It's possible for LZ4-compressed datums to leak into composite type
values stored on disk, just as it is for PGLZ. It's also possible for
LZ4-compressed attributes to be copied into a different table via SQL
commands such as CREATE TABLE AS or INSERT .. SELECT.  It would be
expensive to force such values to be decompressed, so PostgreSQL has
never done so. For the same reasons, we also don't force recompression
of already-compressed values even if the target table prefers a
different compression method than was used for the source data.  These
architectural decisions are perhaps arguable but revisiting them is
well beyond the scope of what seemed possible to do as part of this
project.  However, it's relatively cheap to recompress as part of
VACUUM FULL or CLUSTER, so this commit adjusts those commands to do
so, if the configured compression method of the table happens not to
match what was used for some column value stored therein.

Dilip Kumar. The original patches on which this work was based were
written by Ildus Kurbangaliev, and those were patches were based on
even earlier work by Nikita Glukhov, but the design has since changed
very substantially, since allow a potentially large number of
compression methods that could be added and dropped on a running
system proved too problematic given some of the architectural issues
mentioned above; the choice of which specific compression method to
add first is now different; and a lot of the code has been heavily
refactored.  More recently, Justin Przyby helped quite a bit with
testing and reviewing and this version also includes some code
contributions from him. Other design input and review from Tomas
Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander
Korotkov, and me.

Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain
Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
2021-03-19 15:10:38 -04:00
Tom Lane 1d581ce712 Fix misuse of foreach_delete_current().
Our coding convention requires this macro's result to be assigned
back to the original List variable.  In this usage, since the
List could not become empty, there was no actual bug --- but
some compilers warned about it.  Oversight in be45be9c3.

Discussion: https://postgr.es/m/35077b31-2d62-1e31-0e2e-ddb52d590b73@enterprisedb.com
2021-03-18 19:24:22 -04:00
Tomas Vondra be45be9c33 Implement GROUP BY DISTINCT
With grouping sets, it's possible that some of the grouping sets are
duplicate.  This is especially common with CUBE and ROLLUP clauses. For
example GROUP BY CUBE (a,b), CUBE (b,c) is equivalent to

  GROUP BY GROUPING SETS (
    (a, b, c),
    (a, b, c),
    (a, b, c),
    (a, b),
    (a, b),
    (a, b),
    (a),
    (a),
    (a),
    (c, a),
    (c, a),
    (c, a),
    (c),
    (b, c),
    (b),
    ()
  )

Some of the grouping sets are calculated multiple times, which is mostly
unnecessary.  This commit implements a new GROUP BY DISTINCT feature, as
defined in the SQL standard, which eliminates the duplicate sets.

Author: Vik Fearing
Reviewed-by: Erik Rijkers, Georgios Kokolatos, Tomas Vondra
Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org
2021-03-18 18:22:18 +01:00
Tom Lane f52c5d6749 Forbid marking an identity column as nullable.
GENERATED ALWAYS AS IDENTITY implies NOT NULL, but the code failed
to complain if you overrode that with "GENERATED ALWAYS AS IDENTITY
NULL".  One might think the old behavior was a feature, but it was
inconsistent because the outcome varied depending on the order of
the clauses, so it seems to have been just an oversight.

Per bug #16913 from Pavel Boev.  Back-patch to v10 where identity
columns were introduced.

Vik Fearing (minor tweaks by me)

Discussion: https://postgr.es/m/16913-3b5198410f67d8c6@postgresql.org
2021-03-12 11:08:42 -05:00
Peter Eisentraut f4adc41c4f Enhanced cycle mark values
Per SQL:202x draft, in the CYCLE clause of a recursive query, the
cycle mark values can be of type boolean and can be omitted, in which
case they default to TRUE and FALSE.

Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
2021-02-27 08:13:24 +01:00
Tom Lane 80ca8464fe Fix list-manipulation bug in WITH RECURSIVE processing.
makeDependencyGraphWalker and checkWellFormedRecursionWalker
thought they could hold onto a pointer to a list's first
cons cell while the list was modified by recursive calls.
That was okay when the cons cell was actually separately
palloc'd ... but since commit 1cff1b95a, it's quite unsafe,
leading to core dumps or incorrect complaints of faulty
WITH nesting.

In the field this'd require at least a seven-deep WITH nest
to cause an issue, but enabling DEBUG_LIST_MEMORY_USAGE
allows the bug to be seen with lesser nesting depths.

Per bug #16801 from Alexander Lakhin.  Back-patch to v13.

Michael Paquier and Tom Lane

Discussion: https://postgr.es/m/16801-393c7922143eaa4d@postgresql.org
2021-02-25 20:47:32 -05:00
Peter Eisentraut 0e392fcc0d Use errmsg_internal for debug messages
An inconsistent set of debug-level messages was not using
errmsg_internal(), thus uselessly exposing the messages to translation
work.  Fix those.
2021-02-17 11:33:25 +01:00
Tom Lane d4c746516b Remove no-longer-used RTE argument of markVarForSelectPriv().
In the wake of c028faf2a, this is no longer needed.  I left it
out of that patch since the API change would be undesirable in
a released branch; but there's no reason not to do it in HEAD.
2021-02-11 11:23:25 -05:00
Tom Lane c028faf2a6 Fix mishandling of column-level SELECT privileges for join aliases.
scanNSItemForColumn, expandNSItemAttrs, and ExpandSingleTable would
pass the wrong RTE to markVarForSelectPriv when dealing with a join
ParseNamespaceItem: they'd pass the join RTE, when what we need to
mark is the base table that the join column came from.  The end
result was to not fill the base table's selectedCols bitmap correctly,
resulting in an understatement of the set of columns that are read
by the query.  The executor would still insist on there being at
least one selectable column; but with a correctly crafted query,
a user having SELECT privilege on just one column of a table would
nonetheless be allowed to read all its columns.

To fix, make markRTEForSelectPriv fetch the correct RTE for itself,
ignoring the possibly-mismatched RTE passed by the caller.  Later,
we'll get rid of some now-unused RTE arguments, but that risks
API breaks so we won't do it in released branches.

This problem was introduced by commit 9ce77d75c, so back-patch
to v13 where that came in.  Thanks to Sven Klemm for reporting
the problem.

Security: CVE-2021-20229
2021-02-08 10:14:09 -05:00
Peter Eisentraut 3696a600e2 SEARCH and CYCLE clauses
This adds the SQL standard feature that adds the SEARCH and CYCLE
clauses to recursive queries to be able to do produce breadth- or
depth-first search orders and detect cycles.  These clauses can be
rewritten into queries using existing syntax, and that is what this
patch does in the rewriter.

Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
2021-02-01 14:32:51 +01:00
Peter Eisentraut 6aaaa76bb4 Allow GRANTED BY clause in normal GRANT and REVOKE statements
The SQL standard allows a GRANTED BY clause on GRANT and
REVOKE (privilege) statements that can specify CURRENT_USER or
CURRENT_ROLE.  In PostgreSQL, both of these are the default behavior.
Since we already have all the parsing support for this for the
GRANT (role) statement, we might as well add basic support for this
for the privilege variant as well.  This allows us to check off SQL
feature T332.  In the future, perhaps more interesting things could be
done with this, too.

Reviewed-by: Simon Riggs <simon@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/f2feac44-b4c5-f38f-3699-2851d6a76dc9@2ndquadrant.com
2021-01-30 09:45:11 +01:00
Tom Lane 7cd9765f9b Re-allow DISTINCT in pl/pgsql expressions.
I'd omitted this from the grammar in commit c9d529848, figuring that
it wasn't worth supporting.  However we already have one complaint,
so it seems that judgment was wrong.  It doesn't require a huge
amount of code, so add it back.  (I'm still drawing the line at
UNION/INTERSECT/EXCEPT though: those'd require an unreasonable
amount of grammar refactoring, and the single-result-row restriction
makes them near useless anyway.)

Also rethink the documentation: this behavior is a property of
all pl/pgsql expressions, not just assignments.

Discussion: https://postgr.es/m/20210122134106.e94c5cd7@mail.verfriemelt.org
2021-01-22 16:26:22 -05:00
Tom Lane c9d5298485 Re-implement pl/pgsql's expression and assignment parsing.
Invent new RawParseModes that allow the core grammar to handle
pl/pgsql expressions and assignments directly, and thereby get rid
of a lot of hackery in pl/pgsql's parser.  This moves a good deal
of knowledge about pl/pgsql into the core code: notably, we have to
invent a CoercionContext that matches pl/pgsql's (rather dubious)
historical behavior for assignment coercions.  That's getting away
from the original idea of pl/pgsql as an arm's-length extension of
the core, but really we crossed that bridge a long time ago.

The main advantage of doing this is that we can now use the core
parser to generate FieldStore and/or SubscriptingRef nodes to handle
assignments to pl/pgsql variables that are records or arrays.  That
fixes a number of cases that had never been implemented in pl/pgsql
assignment, such as nested records and array slicing, and it allows
pl/pgsql assignment to support the datatype-specific subscripting
behaviors introduced in commit c7aba7c14.

There are cosmetic benefits too: when a syntax error occurs in a
pl/pgsql expression, the error report no longer includes the confusing
"SELECT" keyword that used to get prefixed to the expression text.
Also, there seem to be some small speed gains.

Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-04 11:52:00 -05:00
Tom Lane 844fe9f159 Add the ability for the core grammar to have more than one parse target.
This patch essentially allows gram.y to implement a family of related
syntax trees, rather than necessarily always parsing a list of SQL
statements.  raw_parser() gains a new argument, enum RawParseMode,
to say what to do.  As proof of concept, add a mode that just parses
a TypeName without any other decoration, and use that to greatly
simplify typeStringToTypeName().

In addition, invent a new SPI entry point SPI_prepare_extended() to
allow SPI users (particularly plpgsql) to get at this new functionality.
In hopes of making this the last variant of SPI_prepare(), set up its
additional arguments as a struct rather than direct arguments, and
promise that future additions to the struct can default to zero.
SPI_prepare_cursor() and SPI_prepare_params() can perhaps go away at
some point.

Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-04 11:03:22 -05:00
Bruce Momjian ca3b37487b Update copyright for 2021
Backpatch-through: 9.5
2021-01-02 13:06:25 -05:00
Alexander Korotkov 6df7a9698b Multirange datatypes
Multiranges are basically sorted arrays of non-overlapping ranges with
set-theoretic operations defined over them.

Since v14, each range type automatically gets a corresponding multirange
datatype.  There are both manual and automatic mechanisms for naming multirange
types.  Once can specify multirange type name using multirange_type_name
attribute in CREATE TYPE.  Otherwise, a multirange type name is generated
automatically.  If the range type name contains "range" then we change that to
"multirange".  Otherwise, we add "_multirange" to the end.

Implementation of multiranges comes with a space-efficient internal
representation format, which evades extra paddings and duplicated storage of
oids.  Altogether this format allows fetching a particular range by its index
in O(n).

Statistic gathering and selectivity estimation are implemented for multiranges.
For this purpose, stored multirange is approximated as union range without gaps.
This field will likely need improvements in the future.

Catversion is bumped.

Discussion: https://postgr.es/m/CALNJ-vSUpQ_Y%3DjXvTxt1VYFztaBSsWVXeF1y6gTYQ4bOiWDLgQ%40mail.gmail.com
Discussion: https://postgr.es/m/a0b8026459d1e6167933be2104a6174e7d40d0ab.camel%40j-davis.com#fe7218c83b08068bfffb0c5293eceda0
Author: Paul Jungwirth, revised by me
Reviewed-by: David Fetter, Corey Huinker, Jeff Davis, Pavel Stehule
Reviewed-by: Alvaro Herrera, Tom Lane, Isaac Morland, David G. Johnston
Reviewed-by: Zhihong Yu, Alexander Korotkov
2020-12-20 07:20:33 +03:00
Tom Lane b3817f5f77 Improve hash_create()'s API for some added robustness.
Invent a new flag bit HASH_STRINGS to specify C-string hashing, which
was formerly the default; and add assertions insisting that exactly
one of the bits HASH_STRINGS, HASH_BLOBS, and HASH_FUNCTION be set.
This is in hopes of preventing recurrences of the type of oversight
fixed in commit a1b8aa1e4 (i.e., mistakenly omitting HASH_BLOBS).

Also, when HASH_STRINGS is specified, insist that the keysize be
more than 8 bytes.  This is a heuristic, but it should catch
accidental use of HASH_STRINGS for integer or pointer keys.
(Nearly all existing use-cases set the keysize to NAMEDATALEN or
more, so there's little reason to think this restriction should
be problematic.)

Tweak hash_create() to insist that the HASH_ELEM flag be set, and
remove the defaults it had for keysize and entrysize.  Since those
defaults were undocumented and basically useless, no callers
omitted HASH_ELEM anyway.

Also, remove memset's zeroing the HASHCTL parameter struct from
those callers that had one.  This has never been really necessary,
and while it wasn't a bad coding convention it was confusing that
some callers did it and some did not.  We might as well save a few
cycles by standardizing on "not".

Also improve the documentation for hash_create().

In passing, improve reinit.c's usage of a hash table by storing
the key as a binary Oid rather than a string; and, since that's
a temporary hash table, allocate it in CurrentMemoryContext for
neatness.

Discussion: https://postgr.es/m/590625.1607878171@sss.pgh.pa.us
2020-12-15 11:38:53 -05:00
Tom Lane 653aa603f5 Provide an error cursor for "can't subscript" error messages.
Commit c7aba7c14 didn't add this, but after more fooling with the
feature I feel that it'd be useful.  To make this possible, refactor
getSubscriptingRoutines() so that the caller is responsible for
throwing any error.  (In clauses.c, I just chose to make the
most conservative assumption rather than throwing an error.  We don't
expect failures there anyway really, so the code space for an error
message would be a poor investment.)
2020-12-11 18:58:21 -05:00
Tom Lane c7aba7c14e Support subscripting of arbitrary types, not only arrays.
This patch generalizes the subscripting infrastructure so that any
data type can be subscripted, if it provides a handler function to
define what that means.  Traditional variable-length (varlena) arrays
all use array_subscript_handler(), while the existing fixed-length
types that support subscripting use raw_array_subscript_handler().
It's expected that other types that want to use subscripting notation
will define their own handlers.  (This patch provides no such new
features, though; it only lays the foundation for them.)

To do this, move the parser's semantic processing of subscripts
(including coercion to whatever data type is required) into a
method callback supplied by the handler.  On the execution side,
replace the ExecEvalSubscriptingRef* layer of functions with direct
calls to callback-supplied execution routines.  (Thus, essentially
no new run-time overhead should be caused by this patch.  Indeed,
there is room to remove some overhead by supplying specialized
execution routines.  This patch does a little bit in that line,
but more could be done.)

Additional work is required here and there to remove formerly
hard-wired assumptions about the result type, collation, etc
of a SubscriptingRef expression node; and to remove assumptions
that the subscript values must be integers.

One useful side-effect of this is that we now have a less squishy
mechanism for identifying whether a data type is a "true" array:
instead of wiring in weird rules about typlen, we can look to see
if pg_type.typsubscript == F_ARRAY_SUBSCRIPT_HANDLER.  For this
to be bulletproof, we have to forbid user-defined types from using
that handler directly; but there seems no good reason for them to
do so.

This patch also removes assumptions that the number of subscripts
is limited to MAXDIM (6), or indeed has any hard-wired limit.
That limit still applies to types handled by array_subscript_handler
or raw_array_subscript_handler, but to discourage other dependencies
on this constant, I've moved it from c.h to utils/array.h.

Dmitry Dolgov, reviewed at various times by Tom Lane, Arthur Zakirov,
Peter Eisentraut, Pavel Stehule

Discussion: https://postgr.es/m/CA+q6zcVDuGBv=M0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w@mail.gmail.com
Discussion: https://postgr.es/m/CA+q6zcVovR+XY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA@mail.gmail.com
2020-12-09 12:40:37 -05:00
Tom Lane a676386b58 Remove operator_precedence_warning.
This GUC was always intended as a temporary solution to help with
finding 9.4-to-9.5 migration issues.  Now that all pre-9.5 branches
are out of support, and 9.5 will be too before v14 is released,
it seems like it's okay to drop it.  Doing so allows removal of
several hundred lines of poorly-tested code in parse_expr.c,
which have been a fertile source of bugs when people did use this.

Discussion: https://postgr.es/m/2234320.1607117945@sss.pgh.pa.us
2020-12-08 16:29:52 -05:00
Peter Eisentraut a6964bc1bb Remove unnecessary grammar symbols
Instead of publication_name_list, we can use name_list.  We already
refer to publications everywhere else by the 'name' or 'name_list'
symbols, so this only improves consistency.

Reviewed-by: https://www.postgresql.org/message-id/flat/3e3ccddb-41bd-ecd8-29fe-195e34d9886f%40enterprisedb.com
Discussion: Tom Lane <tgl@sss.pgh.pa.us>
2020-12-04 11:16:26 +01:00
Peter Eisentraut 6114040711 Small code simplifications
strVal() can be used in a couple of places instead of coding the same
thing by hand.
2020-12-03 11:44:13 +01:00
Michael Paquier b5913f6120 Refactor CLUSTER and REINDEX grammar to use DefElem for option lists
This changes CLUSTER and REINDEX so as a parenthesized grammar becomes
possible for options, while unifying the grammar parsing rules for
option lists with the existing ones.

This is a follow-up of the work done in 873ea9e for VACUUM, ANALYZE and
EXPLAIN.  This benefits REINDEX for a potential backend-side filtering
for collatable-sensitive indexes and TABLESPACE, while CLUSTER would
benefit from the latter.

Author: Alexey Kondratov, Justin Pryzby
Discussion: https://postgr.es/m/8a8f5f73-00d3-55f8-7583-1375ca8f6a91@postgrespro.ru
2020-12-03 10:13:21 +09:00
Tom Lane f7f83a55bf Ensure that expandTableLikeClause() re-examines the same table.
As it stood, expandTableLikeClause() re-did the same relation_openrv
call that transformTableLikeClause() had done.  However there are
scenarios where this would not find the same table as expected.
We hold lock on the LIKE source table, so it can't be renamed or
dropped, but another table could appear before it in the search path.
This explains the odd behavior reported in bug #16758 when cloning a
table as a temp table of the same name.  This case worked as expected
before commit 502898192 introduced the need to open the source table
twice, so we should fix it.

To make really sure we get the same table, let's re-open it by OID not
name.  That requires adding an OID field to struct TableLikeClause,
which is a little nervous-making from an ABI standpoint, but as long
as it's at the end I don't think there's any serious risk.

Per bug #16758 from Marc Boeren.  Like the previous patch,
back-patch to all supported branches.

Discussion: https://postgr.es/m/16758-840e84a6cfab276d@postgresql.org
2020-12-01 14:02:27 -05:00
Michael Paquier 873ea9ee69 Refactor parsing rules for option lists of EXPLAIN, VACUUM and ANALYZE
Those three commands have been using the same grammar rules to handle a
a list of parenthesized options.  This refactors the code so as they use
the same parsing rules, shaving some code.  A future commit will make
use of those option parsing rules for more utility commands, like
REINDEX and CLUSTER.

Author: Alexey Kondratov, Justin Pryzby
Discussion: https://postgr.es/m/8a8f5f73-00d3-55f8-7583-1375ca8f6a91@postgrespro.ru
2020-11-30 20:27:37 +09:00
Heikki Linnakangas 0a2bc5d61e Move per-agg and per-trans duplicate finding to the planner.
This has the advantage that the cost estimates for aggregates can count
the number of calls to transition and final functions correctly.

Bump catalog version, because views can contain Aggrefs.

Reviewed-by: Andres Freund
Discussion: https://www.postgresql.org/message-id/b2e3536b-1dbc-8303-c97e-89cb0b4a9a48%40iki.fi
2020-11-24 10:45:00 +02:00
Tom Lane 926fa801ac Remove undocumented IS [NOT] OF syntax.
This feature was added a long time ago, in 7c1e67bd5 and eb121ba2c,
but never documented in any user-facing way.  (Documentation added
in 6126d3e70 was commented out almost immediately, in 8272fc3f7.)
That's because, while this syntax is defined by SQL:99, our
implementation is only vaguely related to the standard's semantics.
The standard appears to intend a run-time not parse-time test, and
it definitely intends that the test should understand subtype
relationships.

No one has stepped up to fix that in the intervening years, but
people keep coming across the code and asking why it's not documented.
Let's just get rid of it: if anyone ever wants to make it work per
spec, they can easily recover whatever parts of this code are still
of value from our git history.

If there's anyone out there who's actually using this despite its
undocumented status, they can switch to using pg_typeof() instead,
eg. "pg_typeof(something) = 'mytype'::regtype".  That gives
essentially the same semantics as what our IS OF code did.
(We didn't have that function last time this was discussed, or
we would have ripped out IS OF then.)

Discussion: https://postgr.es/m/CAKFQuwZ2pTc-DSkOiTfjauqLYkNREeNZvWmeg12Q-_69D+sYZA@mail.gmail.com
Discussion: https://postgr.es/m/BAY20-F23E9F2B4DAB3E4E88D3623F99B0@phx.gbl
Discussion: https://postgr.es/m/3E7CF81D.1000203@joeconway.com
2020-11-19 17:39:39 -05:00
Tom Lane 97390fe8a6 Further fixes for CREATE TABLE LIKE: cope with self-referential FKs.
Commit 502898192 was too careless about the order of execution of the
additional ALTER TABLE operations generated by expandTableLikeClause.
It just stuck them all at the end, which seems okay for most purposes.
But it falls down in the case where LIKE is importing a primary key
or unique index and the outer CREATE TABLE includes a FOREIGN KEY
constraint that needs to depend on that index.  Weird as that is,
it used to work, so we ought to keep it working.

To fix, make parse_utilcmd.c insert LIKE clauses between index-creation
and FK-creation commands in the transformed list of commands, and change
utility.c so that the commands generated by expandTableLikeClause are
executed immediately not at the end.  One could imagine scenarios where
this wouldn't work either; but currently expandTableLikeClause only
makes column default expressions, CHECK constraints, and indexes, and
this ordering seems fine for those.

Per bug #16730 from Sofoklis Papasofokli.  Like the previous patch,
back-patch to all supported branches.

Discussion: https://postgr.es/m/16730-b902f7e6e0276b30@postgresql.org
2020-11-19 15:03:17 -05:00
Peter Eisentraut 5664b7be5b Normalize comment in empty grammar rules
Change lower case /* empty */ to /* EMPTY */ for consistency with the
majority.

Discussion: https://www.postgresql.org/message-id/flat/e9eed669-e32d-6919-fed4-acc0daea857b%40enterprisedb.com
2020-11-16 11:54:52 +01:00
Tom Lane 92bf7e2d02 Provide the OR REPLACE option for CREATE TRIGGER.
This is mostly straightforward.  However, we disallow replacing
constraint triggers or changing the is-constraint property; perhaps
that can be added later, but the complexity versus benefit tradeoff
doesn't look very good.

Also, no special thought is taken here for whether replacing an
existing trigger should result in changes to queued-but-not-fired
trigger actions.  We just document that if you're surprised by the
results, too bad, don't do that.  (Note that any such pending trigger
activity would have to be within the current session.)

Takamichi Osumi, reviewed at various times by Surafel Temesgen,
Peter Smith, and myself

Discussion: https://postgr.es/m/0DDF369B45A1B44B8A687ED43F06557C010BC362@G01JPEXMBYT03
2020-11-14 17:05:34 -05:00
Peter Eisentraut 1b2b19f758 Clean up optional rules in grammar
Various rules for optional keywords contained unnecessary rules and
type declarations.  Remove those, thus making the output a tiny bit
smaller.

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/e9eed669-e32d-6919-fed4-acc0daea857b%40enterprisedb.com
2020-11-12 08:06:08 +01:00
Peter Eisentraut 0af302af40 Fix some stray whitespace in parser files 2020-11-11 17:37:18 +01:00
Peter Eisentraut c77f6f50e4 Fix cases of discarding result from list API functions
Two cases violated list APIs by throwing away the return value.  While
the code was technically correct, it relied on internal knowledge of
the list implementation, and the code wasn't really gaining anything
that way.  It is planned to make this a compiler warning in the
future, so just fix these cases by assigning the return value
properly.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/e3753562-99cd-b65f-5aca-687dfd1ec2fc@2ndquadrant.com
2020-11-11 08:03:51 +01:00
Tom Lane 40c24bfef9 Improve our ability to regurgitate SQL-syntax function calls.
The SQL spec calls out nonstandard syntax for certain function calls,
for example substring() with numeric position info is supposed to be
spelled "SUBSTRING(string FROM start FOR count)".  We accept many
of these things, but up to now would not print them in the same format,
instead simplifying down to "substring"(string, start, count).
That's long annoyed me because it creates an interoperability
problem: we're gratuitously injecting Postgres-specific syntax into
what might otherwise be a perfectly spec-compliant view definition.
However, the real reason for addressing it right now is to support
a planned change in the semantics of EXTRACT() a/k/a date_part().
When we switch that to returning numeric, we'll have the parser
translate EXTRACT() to some new function name (might as well be
"extract" if you ask me) and then teach ruleutils.c to reverse-list
that per SQL spec.  In this way existing calls to date_part() will
continue to have the old semantics.

To implement this, invent a new CoercionForm value COERCE_SQL_SYNTAX,
and make the parser insert that rather than COERCE_EXPLICIT_CALL when
the input has SQL-spec decoration.  (But if the input has the form of
a plain function call, continue to mark it COERCE_EXPLICIT_CALL, even
if it's calling one of these functions.)  Then ruleutils.c recognizes
COERCE_SQL_SYNTAX as a cue to emit SQL call syntax.  It can know
which decoration to emit using hard-wired knowledge about the
functions that could be called this way.  (While this solution isn't
extensible without manual additions, neither is the grammar, so this
doesn't seem unmaintainable.)  Notice that this solution will
reverse-list a function call with SQL decoration only if it was
entered that way; so dump-and-reload will not by itself produce any
changes in the appearance of views.

This requires adding a CoercionForm field to struct FuncCall.
(I couldn't resist the temptation to rearrange that struct's
field order a tad while I was at it.)  FuncCall doesn't appear
in stored rules, so that change isn't a reason for a catversion
bump, but I did one anyway because the new enum value for
CoercionForm fields could confuse old backend code.

Possible future work:

* Perhaps CoercionForm should now be renamed to DisplayForm,
or something like that, to reflect its more general meaning.
This'd require touching a couple hundred places, so it's not
clear it's worth the code churn.

* The SQLValueFunction node type, which was invented partly for
the same goal of improving SQL-compatibility of view output,
could perhaps be replaced with regular function calls marked
with COERCE_SQL_SYNTAX.  It's unclear if this would be a net
code savings, however.

Discussion: https://postgr.es/m/42b73d2d-da12-ba9f-570a-420e0cce19d9@phystech.edu
2020-11-04 12:34:50 -05:00
Thomas Munro 257836a755 Track collation versions for indexes.
Record the current version of dependent collations in pg_depend when
creating or rebuilding an index.  When accessing the index later, warn
that the index may be corrupted if the current version doesn't match.

Thanks to Douglas Doole, Peter Eisentraut, Christoph Berg, Laurenz Albe,
Michael Paquier, Robert Haas, Tom Lane and others for very helpful
discussion.

Author: Thomas Munro <thomas.munro@gmail.com>
Author: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> (earlier versions)
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
2020-11-03 01:19:50 +13:00
Thomas Munro 7d1297df08 Remove pg_collation.collversion.
This model couldn't be extended to cover the default collation, and
didn't have any information about the affected database objects when the
version changed.  Remove, in preparation for a follow-up commit that
will add a new mechanism.

Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
2020-11-03 00:44:59 +13:00
Tom Lane ad77039fad Calculate extraUpdatedCols in query rewriter, not parser.
It's unsafe to do this at parse time because addition of generated
columns to a table would not invalidate stored rules containing
UPDATEs on the table ... but there might now be dependent generated
columns that were not there when the rule was made.  This also fixes
an oversight that rewriteTargetView failed to update extraUpdatedCols
when transforming an UPDATE on an updatable view.  (Since the new
calculation is downstream of that, rewriteTargetView doesn't actually
need to do anything; but before, there was a demonstrable bug there.)

In v13 and HEAD, this leads to easily-visible bugs because (since
commit c6679e4fc) we won't recalculate generated columns that aren't
listed in extraUpdatedCols.  In v12 this bitmap is mostly just used
for trigger-firing decisions, so you'd only notice a problem if a
trigger cared whether a generated column had been updated.

I'd complained about this back in May, but then forgot about it
until bug #16671 from Michael Paul Killian revived the issue.

Back-patch to v12 where this field was introduced.  If existing
stored rules contain any extraUpdatedCols values, they'll be
ignored because the rewriter will overwrite them, so the bug will
be fixed even for existing rules.  (But note that if someone were
to update to 13.1 or 12.5, store some rules with UPDATEs on tables
having generated columns, and then downgrade to a prior minor version,
they might observe issues similar to what this patch fixes.  That
seems unlikely enough to not be worth going to a lot of effort to fix.)

Discussion: https://postgr.es/m/10206.1588964727@sss.pgh.pa.us
Discussion: https://postgr.es/m/16671-2fa55851859fb166@postgresql.org
2020-10-28 13:47:02 -04:00
Peter Eisentraut f893e68d76 Add select_common_typmod()
This accompanies select_common_type() and select_common_collation().
Typmods were previously combined using hand-coded logic in several
places.  The logic in select_common_typmod() isn't very exciting, but
it makes the code more compact and readable in a few locations, and in
the future we can perhaps do more complicated things if desired.

As a small enhancement, the type unification of the direct and
aggregate arguments of hypothetical-set aggregates now unifies the
typmod as well using this new function, instead of just dropping it.

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/97df3af9-8b5e-fb7f-a029-3eb7e80d7af9@2ndquadrant.com
2020-10-27 18:10:42 +01:00
Peter Eisentraut 9213462c53 Make procedure OUT parameters work with JDBC
The JDBC driver sends OUT parameters with type void.  This makes sense
when calling a function, so that the parameters are ignored in
ParseFuncOrColumn().  For a procedure call we want to treat them as
unknown.

Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://www.postgresql.org/message-id/flat/d7e49540-ea92-b4e2-5fff-42036102f968%402ndquadrant.com
2020-10-27 09:01:54 +01:00
David Rowley e7c2b95d37 Optimize a few list_delete_ptr calls
There is a handful of places where we called list_delete_ptr() to remove
some element from a List.  In many of these places we know, or with very
little additional effort know the index of the ListCell that we need to
remove.

Here we change all of those places to instead either use one of;
list_delete_nth_cell(), foreach_delete_current() or list_delete_last().
Each of these saves from having to iterate over the list to search for the
element to remove by its pointer value.

There are some small performance gains to be had by doing this, but in the
general case, none of these lists are likely to be very large, so the
lookup was probably never that expensive anyway.  However, some of the
calls are in fairly hot code paths, e.g process_equivalence().  So any
small gains there are useful.

Author: Zhijie Hou and David Rowley
Discussion: https://postgr.es/m/b3517353ec7c4f87aa560678fbb1034b@G08CNEXMBPEKD05.g08.fujitsu.local
2020-10-22 14:36:32 +13:00
Peter Eisentraut 4e118fc33e Correct error message
Apparently copy-and-pasted from nearby.
2020-10-14 07:54:14 +02:00
Tom Lane 8d2a01ae12 Fix optimization hazard in gram.y's makeOrderedSetArgs(), redux.
It appears that commit cf63c641c, which intended to prevent
misoptimization of the result-building step in makeOrderedSetArgs,
didn't go far enough: buildfarm member hornet's version of xlc
is now optimizing back to the old, broken behavior in which
list_length(directargs) is fetched only after list_concat() has
changed that value.  I'm not entirely convinced whether that's
an undeniable compiler bug or whether it can be justified by a
sufficiently aggressive interpretation of C sequence points.
So let's just change the code to make it harder to misinterpret.

Back-patch to all supported versions, just in case.

Discussion: https://postgr.es/m/1830491.1601944935@sss.pgh.pa.us
2020-10-07 18:41:39 -04:00
Peter Eisentraut 2453ea1422 Support for OUT parameters in procedures
Unlike for functions, OUT parameters for procedures are part of the
signature.  Therefore, they have to be listed in pg_proc.proargtypes
as well as mentioned in ALTER PROCEDURE and DROP PROCEDURE.

Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/2b8490fe-51af-e671-c504-47359dc453c5@2ndquadrant.com
2020-10-05 09:21:43 +02:00
Tom Lane 97b6144826 Make postgres.bki use the same literal-string syntax as postgresql.conf.
The BKI file's string quoting conventions were previously quite weird,
perhaps as a result of repurposing a function built to scan
single-quoted strings to scan double-quoted ones.  Change to use the
same rules as we use in GUC files, allowing some simplifications in
genbki.pl and initdb.c.

While at it, completely remove the backend's scanstr() function, which
was essentially a duplicate of the string dequoting code in guc-file.l.
Instead export that one (under a less generic name than it had) and let
bootscanner.l use it.  Now we can clarify that scansup.c exists only to
support the main lexer. We could alternatively have removed GUC_scanstr,
but this way seems better since the previous arrangement could mislead
a reader into thinking that scanstr() had something to do with the main
lexer's handling of string literals.  Maybe it did once, but if so it
was a long time ago.

This patch does not bump catversion, since the initially-installed
catalog contents don't change.  Note however that successful initdb
after applying this patch will require up-to-date postgres.bki as well
as postgres and initdb executables.

In passing, remove a bunch of very-long-obsolete #include's in
bootparse.y and bootscanner.l.

John Naylor

Discussion: https://postgr.es/m/CACPNZCtDpd18T0KATTmCggO2GdVC4ow86ypiq5ENff1VnauL8g@mail.gmail.com
2020-10-04 16:09:55 -04:00
Tom Lane 56fe008996 Add for_each_from, to simplify loops starting from non-first list cells.
We have a dozen or so places that need to iterate over all but the
first cell of a List.  Prior to v13 this was typically written as
	for_each_cell(lc, lnext(list_head(list)))
Commit 1cff1b95a changed these to
	for_each_cell(lc, list, list_second_cell(list))
This patch introduces a new macro for_each_from() which expresses
the start point as a list index, allowing these to be written as
	for_each_from(lc, list, 1)
This is marginally more efficient, since ForEachState.i can be
initialized directly instead of backing into it from a ListCell
address.  It also seems clearer and less typo-prone.

Some of the remaining uses of for_each_cell() look like they could
profitably be changed to for_each_from(), but here I confined myself
to changing uses of list_second_cell().

Also, fix for_each_cell_setup() and for_both_cell_setup() to
const-ify their arguments; that's a simple oversight in 1cff1b95a.

Back-patch into v13, on the grounds that (1) the const-ification
is a minor bug fix, and (2) it's better for back-patching purposes
if we only have two ways to write these loops rather than three.

In HEAD, also remove list_third_cell() and list_fourth_cell(),
which were also introduced in 1cff1b95a, and are unused as of
cc99baa43.  It seems unlikely that any third-party code would
have started to use them already; anyone who has can be directed
to list_nth_cell instead.

Discussion: https://postgr.es/m/CAApHDvpo1zj9KhEpU2cCRZfSM3Q6XGdhzuAS2v79PH7WJBkYVA@mail.gmail.com
2020-09-28 20:33:13 -04:00
Tom Lane 72647ac3bf Assign collations in partition bound expressions.
Failure to do this can result in errors during evaluation of
the bound expression, as illustrated by the new regression test.

Back-patch to v12 where the ability for partition bounds to be
expressions was added.

Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-28 14:12:38 -04:00
Tom Lane 2dfa3fea88 Remove complaints about COLLATE clauses in partition bound values.
transformPartitionBoundValue went out of its way to do the wrong
thing: there is no reason to complain about a non-matching COLLATE
clause in a partition boundary expression.  We're coercing the
bound expression to the target column type as though by an
implicit assignment, and the rules for implicit assignment say
that collations can be implicitly converted.

What we *do* need to do, and the code is not doing, is apply
assign_expr_collations() to the bound expression.  While this is
merely a definition disagreement, that is a bug that needs to be
back-patched, so I'll commit it separately.

Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-28 13:44:01 -04:00
Tom Lane 6b2c4e59d0 Improve error cursor positions for problems with partition bounds.
We failed to pass down the query string to check_new_partition_bound,
so that its attempts to provide error cursor positions were for naught;
one must have the query string to get parser_errposition to do anything.
Adjust its API to require a ParseState to be passed down.

Also, improve the logic inside check_new_partition_bound so that the
cursor points at the partition bound for the specific column causing
the issue, when one can be identified.

That part is also for naught if we can't determine the query position of
the column with the problem.  Improve transformPartitionBoundValue so
that it makes sure that const-simplified partition expressions will be
properly labeled with positions.  In passing, skip calling evaluate_expr
if the value is already a Const, which is surely the most common case.

Alexandra Wang, Ashwin Agrawal, Amit Langote; reviewed by Ashutosh Bapat

Discussion: https://postgr.es/m/CACiyaSopZoqssfMzgHk6fAkp01cL6vnqBdmTw2C5_KJaFR_aMg@mail.gmail.com
Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-23 18:04:53 -04:00
Tom Lane ce90f075f0 Improve the error message for an inappropriate column definition list.
The existing message about "a column definition list is only allowed for
functions returning "record"" could be given in some cases where it was
fairly confusing; in particular, a function with multiple OUT parameters
*does* return record according to pg_proc.  Break it down into a couple
more cases to deliver a more on-point complaint.  Per complaint from
Bruce Momjian.

Discussion: https://postgr.es/m/798909.1600562993@sss.pgh.pa.us
2020-09-22 10:49:11 -04:00
Peter Eisentraut 80fc96eceb Standardize order of use strict and use warnings in Perl code
The standard order in PostgreSQL and other code is use strict first,
but some code was uselessly inconsistent about this.
2020-09-21 17:04:36 +02:00
Tom Lane 28a61fc6c5 Remove precedence hacks no longer needed without postfix operators.
It's no longer necessary to assign explicit precedences to GENERATED,
NULL_P, PRESERVE, or STRIP_P.

Actually, we don't need to assign precedence to IDENT either; that was
really just there to govern the behavior of target_el's "a_expr IDENT"
production, which no longer ends with that terminal.  However, it seems
like a good idea to continue to do so, because it provides a reference
point for a precedence level that we can assign to other unreserved
keywords that lack a natural precedence level.

Research by Peter Eisentraut and John Naylor; comment rewrite by me.

Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-19 15:11:26 -04:00
Tom Lane 06a7c3154f Allow most keywords to be used as column labels without requiring AS.
Up to now, if you tried to omit "AS" before a column label in a SELECT
list, it would only work if the column label was an IDENT, that is not
any known keyword.  This is rather unfriendly considering that we have
so many keywords and are constantly growing more.  In the wake of commit
1ed6b8956 it's possible to improve matters quite a bit.

We'd originally tried to make this work by having some of the existing
keyword categories be allowed without AS, but that didn't work too well,
because each category contains a few special cases that don't work
without AS.  Instead, invent an entirely orthogonal keyword property
"can be bare column label", and mark all keywords that way for which
we don't get shift/reduce errors by doing so.

It turns out that of our 450 current keywords, all but 39 can be made
bare column labels, improving the situation by over 90%.  This number
might move around a little depending on future grammar work, but it's
a pretty nice improvement.

Mark Dilger, based on work by myself and Robert Haas;
review by John Naylor

Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-18 16:46:36 -04:00
Tom Lane 1ed6b89563 Remove support for postfix (right-unary) operators.
This feature has been a thorn in our sides for a long time, causing
many grammatical ambiguity problems.  It doesn't seem worth the
pain to continue to support it, so remove it.

There are some follow-on improvements we can make in the grammar,
but this commit only removes the bare minimum number of productions,
plus assorted backend support code.

Note that pg_dump and psql continue to have full support, since
they may be used against older servers.  However, pg_dump warns
about postfix operators.  There is also a check in pg_upgrade.

Documentation-wise, I (tgl) largely removed the "left unary"
terminology in favor of saying "prefix operator", which is
a more standard and IMO less confusing term.

I included a catversion bump, although no initial catalog data
changes here, to mark the boundary at which oprkind = 'r'
stopped being valid in pg_operator.

Mark Dilger, based on work by myself and Robert Haas;
review by John Naylor

Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-17 19:38:05 -04:00
Peter Eisentraut 45b9805706 Allow CURRENT_ROLE where CURRENT_USER is accepted
In the particular case of GRANTED BY, this is specified in the SQL
standard.  Since in PostgreSQL, CURRENT_ROLE is equivalent to
CURRENT_USER, and CURRENT_USER is already supported here, adding
CURRENT_ROLE is trivial.  The other cases are PostgreSQL extensions,
but for the same reason it also makes sense there.

Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Asif Rehman <asifr.rehman@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/f2feac44-b4c5-f38f-3699-2851d6a76dc9%402ndquadrant.com
2020-09-17 11:40:08 +02:00
Peter Eisentraut 3e0242b24c Message fixes and style improvements 2020-09-14 06:42:30 +02:00
Tom Lane 53367e6c62 Clarify comments in enforce_generic_type_consistency().
Some of the pre-existing comments were vague about whether they
referred to all polymorphic types or only the old-style ones.

Also be more consistent about using the "family 1" vs "family 2"
terminology.

Himanshu Upadhyaya and Tom Lane

Discussion: https://postgr.es/m/CAPF61jBUg9XoMPNuLpoZ+h6UZ2VxKdNt3rQL1xw1GOBwjWzAXQ@mail.gmail.com
2020-09-07 14:52:33 -04:00
Tom Lane 38a2d70329 Remove some more useless assignments.
Found with clang's scan-build tool.  It also whines about a lot of
other dead stores that we should *not* change IMO, either as a matter
of style or future-proofing.  But these places seem like clear
oversights.

Discussion: https://postgr.es/m/CAEudQAo1+AcGppxDSg8k+zF4+Kv+eJyqzEDdbpDg58-=MQcerQ@mail.gmail.com
2020-09-04 14:32:19 -04:00
Michael Paquier 844c05abc3 Remove variable "concurrent" from ReindexStmt
This node already handles multiple options using a bitmask, so having a
separate boolean flag is not necessary.  This simplifies the code a bit
with less arguments to give to the reindex routines, by replacing the
boolean with an equivalent bitmask value.

Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/20200902110326.GA14963@paquier.xyz
2020-09-04 10:43:32 +09:00
Tom Lane 5028981923 Fix handling of CREATE TABLE LIKE with inheritance.
If a CREATE TABLE command uses both LIKE and traditional inheritance,
Vars in CHECK constraints and expression indexes that are absorbed
from a LIKE parent table tended to get mis-numbered, resulting in
wrong answers and/or bizarre error messages (though probably not any
actual crashes, thanks to validation occurring in the executor).

In v12 and up, the same could happen to Vars in GENERATED expressions,
even in cases with no LIKE clause but multiple traditional-inheritance
parents.

The cause of the problem for LIKE is that parse_utilcmd.c supposed
it could renumber such Vars correctly during transformCreateStmt(),
which it cannot since we have not yet accounted for columns added via
inheritance.  Fix that by postponing processing of LIKE INCLUDING
CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed
DefineRelation().

The error with GENERATED and multiple inheritance is a simple oversight
in MergeAttributes(); it knows it has to renumber Vars in inherited
CHECK constraints, but forgot to apply the same processing to inherited
GENERATED expressions (a/k/a defaults).

Per bug #16272 from Tom Gottfried.  The non-GENERATED variants of the
issue are ancient, presumably dating right back to the addition of
CREATE TABLE LIKE; hence back-patch to all supported branches.

Discussion: https://postgr.es/m/16272-6e32da020e9a9381@postgresql.org
2020-08-21 15:00:47 -04:00
Michael Paquier cc35d8933a Rename field "relkind" to "objtype" for CTAS and ALTER TABLE nodes
"relkind" normally refers to the char field from pg_class.  However, in
the parse nodes AlterTableStmt and CreateTableAsStmt, "relkind" was used
for a field of type enum ObjectType, that could refer to other object
types than those possible for a relkind.  Such fields being usually
named "objtype", switch the name in both structures to make things more
consistent.  Note that this led to some confusion in functions that
also operate on a RangeTableEntry object, which also has a field named
"relkind".

This naming goes back to commit 09d4e96, where only OBJECT_TABLE and
OBJECT_INDEX were used.  This got extended later to use as well
OBJECT_TYPE with e440e12, not really a relation kind.

Author: Mark Dilger
Reviewed-by: Daniel Gustafsson, Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/609181AE-E399-47C7-9221-856E0F96BF93@enterprisedb.com
2020-07-11 13:32:28 +09:00
Andres Freund a9a4a7ad56 code: replace most remaining uses of 'master'.
Author: Andres Freund
Reviewed-By: David Steele
Discussion: https://postgr.es/m/20200615182235.x7lch5n6kcjq4aue@alap3.anarazel.de
2020-07-08 13:24:35 -07:00
Tom Lane c410af098c Mop up some no-longer-necessary hacks around printf %.*s format.
Commit 54cd4f045 added some kluges to work around an old glibc bug,
namely that %.*s could misbehave if glibc thought any characters in
the supplied string were incorrectly encoded.  Now that we use our
own snprintf.c implementation, we need not worry about that bug (even
if it still exists in the wild).  Revert a couple of particularly
ugly hacks, and remove or improve assorted comments.

Note that there can still be encoding-related hazards here: blindly
clipping at a fixed length risks producing wrongly-encoded output
if the clip splits a multibyte character.  However, code that's
doing correct multibyte-aware clipping doesn't really need a comment
about that, while code that isn't needs an explanation why not,
rather than a red-herring comment about an obsolete bug.

Discussion: https://postgr.es/m/279428.1593373684@sss.pgh.pa.us
2020-06-29 17:12:38 -04:00
Peter Eisentraut 78c887679d Add current substring regular expression syntax
SQL:1999 had syntax

    SUBSTRING(text FROM pattern FOR escapechar)

but this was replaced in SQL:2003 by the more clear

    SUBSTRING(text SIMILAR pattern ESCAPE escapechar)

but this was never implemented in PostgreSQL.  This patch adds that
new syntax as an alternative in the parser, and updates documentation
and tests to indicate that this is the preferred alternative now.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/flat/a15db31c-d0f8-8ce0-9039-578a31758adb%402ndquadrant.com
2020-06-29 11:05:00 +02:00
Peter Eisentraut aafefb4dcb Clean up grammar a bit
Simplify the grammar specification of substring() and overlay() a bit,
simplify and update some comments.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/flat/a15db31c-d0f8-8ce0-9039-578a31758adb%402ndquadrant.com
2020-06-29 11:05:00 +02:00