Commit Graph

4029 Commits

Author SHA1 Message Date
Tom Lane fe2b5386b2 Validate the OID argument of pg_import_system_collations().
"SELECT pg_import_system_collations(0)" caused an assertion failure.
With a random nonzero argument --- or indeed with zero, in non-assert
builds --- it would happily make pg_collation entries with garbage
values of collnamespace.  These are harmless as far as I can tell
(unless maybe the OID happens to become used for a schema, later on?).
In any case this isn't a security issue, since the function is
superuser-only.  But it seems like a gotcha for unwary DBAs, so let's
add a check that the given OID belongs to some schema.

Back-patch to v10 where this function was introduced.
2021-03-08 18:21:51 -05:00
Alvaro Herrera 2688852a49
Fix use-after-free bug with AfterTriggersTableData.storeslot
AfterTriggerSaveEvent() wrongly allocates the slot in execution-span
memory context, whereas the correct thing is to allocate it in
a transaction-span context, because that's where the enclosing
AfterTriggersTableData instance belongs into.

Backpatch to 12 (the test back to 11, where it works well with no code
changes, and it's good to have to confirm that the case was previously
well supported); this bug seems introduced by commit ff11e7f4b9.

Reported-by: Bertrand Drouvot <bdrouvot@amazon.com>
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/39a71864-b120-5a5c-8cc5-c632b6f16761@amazon.com
2021-02-27 18:09:15 -03:00
Heikki Linnakangas 8e56684d54 Fix permission checks on constraint violation errors on partitions.
If a cross-partition UPDATE violates a constraint on the target partition,
and the columns in the new partition are in different physical order than
in the parent, the error message can reveal columns that the user does not
have SELECT permission on. A similar bug was fixed earlier in commit
804b6b6db4.

The cause of the bug is that the callers of the
ExecBuildSlotValueDescription() function got confused when constructing
the list of modified columns. If the tuple was routed from a parent, we
converted the tuple to the parent's format, but the list of modified
columns was grabbed directly from the child's RTE entry.

ExecUpdateLockMode() had a similar issue. That lead to confusion on which
columns are key columns, leading to wrong tuple lock being taken on tables
referenced by foreign keys, when a row is updated with INSERT ON CONFLICT
UPDATE. A new isolation test is added for that corner case.

With this patch, the ri_RangeTableIndex field is no longer set for
partitions that don't have an entry in the range table. Previously, it was
set to the RTE entry of the parent relation, but that was confusing.

NOTE: This modifies the ResultRelInfo struct, replacing the
ri_PartitionRoot field with ri_RootResultRelInfo. That's a bit risky to
backpatch, because it breaks any extensions accessing the field. The
change that ri_RangeTableIndex is not set for partitions could potentially
break extensions, too. The ResultRelInfos are visible to FDWs at least,
and this patch required small changes to postgres_fdw. Nevertheless, this
seem like the least bad option. I don't think these fields widely used in
extensions; I don't think there are FDWs out there that uses the FDW
"direct update" API, other than postgres_fdw. If there is, you will get a
compilation error, so hopefully it is caught quickly.

Backpatch to 11, where support for both cross-partition UPDATEs, and unique
indexes on partitioned tables, were added.

Reviewed-by: Amit Langote
Security: CVE-2021-3393
2021-02-08 11:01:55 +02:00
Heikki Linnakangas c87cbd51ee Fix backslash-escaping multibyte chars in COPY FROM.
If a multi-byte character is escaped with a backslash in TEXT mode input,
and the encoding is one of the client-only encodings where the bytes after
the first one can have an ASCII byte "embedded" in the char, we didn't
skip the character correctly. After a backslash, we only skipped the first
byte of the next character, so if it was a multi-byte character, we would
try to process its second byte as if it was a separate character. If it
was one of the characters with special meaning, like '\n', '\r', or
another '\\', that would cause trouble.

One such exmple is the byte sequence '\x5ca45c2e666f6f' in Big5 encoding.
That's supposed to be [backslash][two-byte character][.][f][o][o], but
because the second byte of the two-byte character is 0x5c, we incorrectly
treat it as another backslash. And because the next character is a dot, we
parse it as end-of-copy marker, and throw an "end-of-copy marker corrupt"
error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
2021-02-05 11:19:48 +02:00
Alvaro Herrera 16f69062e5
Remove bogus restriction from BEFORE UPDATE triggers
In trying to protect the user from inconsistent behavior, commit
487e9861d0 "Enable BEFORE row-level triggers for partitioned tables"
tried to prevent BEFORE UPDATE FOR EACH ROW triggers from moving the row
from one partition to another.  However, it turns out that the
restriction is wrong in two ways: first, it fails spuriously, preventing
valid situations from working, as in bug #16794; and second, they don't
protect from any misbehavior, because tuple routing would cope anyway.

Fix by removing that restriction.

We keep the same restriction on BEFORE INSERT FOR EACH ROW triggers,
though.  It is valid and useful there.  In the future we could remove it
by having tuple reroute work for inserts as it does for updates.

Backpatch to 13.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Phillip Menke <pg@pmenke.de>
Discussion: https://postgr.es/m/16794-350a655580fbb9ae@postgresql.org
2021-01-28 16:56:07 -03:00
Noah Misch 6eb3fc7fcd Prevent excess SimpleLruTruncate() deletion.
Every core SLRU wraps around.  With the exception of pg_notify, the wrap
point can fall in the middle of a page.  Account for this in the
PagePrecedes callback specification and in SimpleLruTruncate()'s use of
said callback.  Update each callback implementation to fit the new
specification.  This changes SerialPagePrecedesLogically() from the
style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes().
(Whereas pg_clog and pg_serial share a key space, pg_serial is nothing
like pg_notify.)  The bug fixed here has the same symptoms and user
followup steps as 592a589a04.  Back-patch
to 9.5 (all supported versions).

Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane.

Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
2021-01-16 12:21:38 -08:00
Tomas Vondra d26d4c717d Disallow CREATE STATISTICS on system catalogs
Add a check that CREATE STATISTICS does not add extended statistics on
system catalogs, similarly to indexes etc.  It can be overriden using
the allow_system_table_mods GUC.

This bug exists since 7b504eb282, adding the extended statistics, so
backpatch all the way back to PostgreSQL 10.

Author: Tomas Vondra
Reported-by: Dean Rasheed
Backpatch-through: 10
Discussion: https://postgr.es/m/CAEZATCXAPrrOKwEsyZKQ4uzzJQWBCt6QAvOcgqRGdWwT1zb%2BrQ%40mail.gmail.com
2021-01-15 23:32:54 +01:00
Alvaro Herrera 5b01a6f13f
Prevent drop of tablespaces used by partitioned relations
When a tablespace is used in a partitioned relation (per commits
ca4103025d in pg12 for tables and 33e6c34c32 in pg11 for indexes),
it is possible to drop the tablespace, potentially causing various
problems.  One such was reported in bug #16577, where a rewriting ALTER
TABLE causes a server crash.

Protect against this by using pg_shdepend to keep track of tablespaces
when used for relations that don't keep physical files; we now abort a
tablespace if we see that the tablespace is referenced from any
partitioned relations.

Backpatch this to 11, where this problem has been latent all along.  We
don't try to create pg_shdepend entries for existing partitioned
indexes/tables, but any ones that are modified going forward will be
protected.

Note slight behavior change: when trying to drop a tablespace that
contains both regular tables as well as partitioned ones, you'd
previously get ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE and now you'll
get ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST.  Arguably, the latter is more
correct.

It is possible to add protecting pg_shdepend entries for existing
tables/indexes, by doing
  ALTER TABLE ONLY some_partitioned_table SET TABLESPACE pg_default;
  ALTER TABLE ONLY some_partitioned_table SET TABLESPACE original_tablespace;
for each partitioned table/index that is not in the database default
tablespace.  Because these partitioned objects do not have storage, no
file needs to be actually moved, so it shouldn't take more time than
what's required to acquire locks.

This query can be used to search for such relations:
SELECT ... FROM pg_class WHERE relkind IN ('p', 'I') AND reltablespace <> 0

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/16577-881633a9f9894fd5@postgresql.org
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
2021-01-14 15:32:14 -03:00
Alvaro Herrera 5a1d1b9540
Avoid memcpy() with a NULL source pointer and count == 0
When memcpy() is called on a pointer, the compiler is entitled to assume
that the pointer is not null, which can lead to optimizing nearby code
in potentially undesirable ways.  We still want such optimizations
(gcc's -fdelete-null-pointer-checks) in cases where they're valid.

Related: commit 13bba02271.

Backpatch to pg11, where this particular instance appeared.

Reported-by: Ranier Vilela <ranier.vf@gmail.com>
Reported-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CAEudQApUndmQkr5fLrCKXQ7+ib44i7S+Kk93pyVThS85PnG3bQ@mail.gmail.com
Discussion: https://postgr.es/m/CALNJ-vSdhwSM5f4tnNn1cdLHvXMVe_S+V3nR5GwNrmCPNB2VtQ@mail.gmail.com
2020-12-01 11:46:56 -03:00
Heikki Linnakangas 74d6fb0a03 Remove leftover comments, left behind by removal of WITH OIDS.
Author: Amit Langote
Discussion: https://www.postgresql.org/message-id/CA%2BHiwqGaRoF3XrhPW-Y7P%2BG7bKo84Z_h%3DkQHvMh-80%3Dav3wmOw%40mail.gmail.com
2020-11-30 10:29:18 +02:00
Tom Lane f5de090cc1 Fix a recently-introduced race condition in LISTEN/NOTIFY handling.
Commit 566372b3d fixed some race conditions involving concurrent
SimpleLruTruncate calls, but it introduced new ones in async.c.
A newly-listening backend could attempt to read Notify SLRU pages that
were in process of being truncated, possibly causing an error.  Also,
the QUEUE_TAIL pointer could become set to a value that's not equal to
the queue position of any backend.  While that's fairly harmless in
v13 and up (thanks to commit 51004c717), in older branches it resulted
in near-permanent disabling of the queue truncation logic, so that
continued use of NOTIFY led to queue-fill warnings and eventual
inability to send any more notifies.  (A server restart is enough to
make that go away, but it's still pretty unpleasant.)

The core of the problem is confusion about whether QUEUE_TAIL
represents the "logical" tail of the queue (i.e., the oldest
still-interesting data) or the "physical" tail (the oldest data we've
not yet truncated away).  To fix, split that into two variables.
QUEUE_TAIL regains its definition as the logical tail, and we
introduce a new variable to track the oldest un-truncated page.

Per report from Mikael Gustavsson.  Like the previous patch,
back-patch to all supported branches.

Discussion: https://postgr.es/m/1b8561412e8a4f038d7a491c8b922788@smhi.se
2020-11-28 14:03:40 -05:00
Tom Lane 53c7b4f622 Use "true" not "TRUE" in one ICU function call.
This was evidently missed in commit 6337865f3, which generally did
s/TRUE/true/ everywhere.  It escaped notice up to now because ICU
versions before ICU 68 provided definitions of "TRUE" and "FALSE"
regardless.  With ICU 68, it fails to compile.

Per report from Condor.  Back-patch to v11 where 6337865f3 came in.
(I've not tested v10, where this call originated, but I imagine
it's fine since we defined TRUE in c.h back then.)

Discussion: https://postgr.es/m/7a6f3336165bfe3ca66abcda7966f9d0@stz-bg.com
2020-11-16 15:16:39 -05:00
Tom Lane 7c89246d0b Fix fuzzy thinking about amcanmulticol versus amcaninclude.
These flags should be independent: in particular an index AM should
be able to say that it supports include columns without necessarily
supporting multiple key columns.  The included-columns patch got
this wrong, possibly aided by the fact that it didn't bother to
update the documentation.

While here, clarify some text about amcanreturn, which was a little
vague about what should happen when amcanreturn reports that only
some of the index columns are returnable.

Noted while reviewing the SP-GiST included-columns patch, which
quite incorrectly (and unsafely) changed SP-GiST to claim
amcanmulticol = true as a workaround for this bug.

Backpatch to v11 where included columns were introduced.
2020-11-15 16:10:48 -05:00
Noah Misch c90c84b3f7 In security-restricted operations, block enqueue of at-commit user code.
Specifically, this blocks DECLARE ... WITH HOLD and firing of deferred
triggers within index expressions and materialized view queries.  An
attacker having permission to create non-temp objects in at least one
schema could execute arbitrary SQL functions under the identity of the
bootstrap superuser.  One can work around the vulnerability by disabling
autovacuum and not manually running ANALYZE, CLUSTER, REINDEX, CREATE
INDEX, VACUUM FULL, or REFRESH MATERIALIZED VIEW.  (Don't restore from
pg_dump, since it runs some of those commands.)  Plain VACUUM (without
FULL) is safe, and all commands are fine when a trusted user owns the
target object.  Performance may degrade quickly under this workaround,
however.  Back-patch to 9.5 (all supported versions).

Reviewed by Robert Haas.  Reported by Etienne Stalmans.

Security: CVE-2020-25695
2020-11-09 07:32:12 -08:00
Tom Lane 7aeb6404f0 In INSERT/UPDATE, use the table's real tuple descriptor as target.
This back-patches commit 20d3fe900 into the v12 and v13 branches.
At the time I thought that commit was not fixing any observable
bug, but Bertrand Drouvot showed otherwise: adding a dropped column
to the previously-considered scenario crashes v12 and v13, unless the
dropped column happens to be an integer.  That is, of course, because
the tupdesc we derive from the plan output tlist fails to describe
the dropped column accurately, so that we'll do the wrong thing with
a tuple in which that column isn't NULL.

There is no bug in pre-v12 branches because they already did use
the table's real tuple descriptor for any trigger-returned tuple.
It seems that this set of bugs can be blamed on the changes that
removed es_trig_tuple_slot, though I've not attempted to pin that
down precisely.

Although there's no code change needed in HEAD, update the test case
to include a dropped column there too.

Discussion: https://postgr.es/m/db5d97c8-f48a-51e2-7b08-b73d5434d425@amazon.com
Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
2020-11-08 13:08:36 -05:00
Alvaro Herrera 99f9384ea9
Message style improvements
* Avoid pointlessly highlighting that an index vacuum was executed by a
  parallel worker; user doesn't care.

* Don't give the impression that a non-concurrent reindex of an invalid
  index on a TOAST table would work, because it wouldn't.

* Add a "translator:" comment for a mysterious message.

Discussion: https://postgr.es/m/20201107034943.GA16596@alvherre.pgsql
Reviewed-by: Michael Paquier <michael@paquier.xyz>
2020-11-07 19:33:43 -03:00
Tom Lane 4352c2394a Revert "Accept relations of any kind in LOCK TABLE".
Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all
branches.  We need to think a bit harder about what the behavior
of LOCK TABLE on views should be, and there's no time for that
before next week's releases.  We'll take another crack at this
later.

Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
2020-11-06 16:17:56 -05:00
Tom Lane 44b973b910 Don't throw an error for LOCK TABLE on a self-referential view.
LOCK TABLE has complained about "infinite recursion" when applied
to a self-referential view, ever since we made it recurse into views
in v11.  However, that breaks pg_dump's new assumption that it's
okay to lock every relation.  There doesn't seem to be any good
reason to throw an error: if we just abandon the recursion, we've
still satisfied the requirement of locking every referenced relation.

Per bug #16703 from Andrew Bille (via Alexander Lakhin).

Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
2020-11-05 11:44:32 -05:00
Tom Lane 768dbef0d4 Allow users with BYPASSRLS to alter their own passwords.
The intention in commit 491c029db was to require superuserness to
change the BYPASSRLS property, but the actual effect of the coding
in AlterRole() was to require superuserness to change anything at all
about a BYPASSRLS role.  Other properties of a BYPASSRLS role should
be changeable under the same rules as for a normal role, though.

Fix that, and also take care of some documentation omissions related
to BYPASSRLS and REPLICATION role properties.

Tom Lane and Stephen Frost, per bug report from Wolfgang Walther.
Back-patch to all supported branches.

Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de
2020-11-03 15:41:32 -05:00
Peter Eisentraut 5397759817 Disallow ALTER TABLE ONLY / DROP EXPRESSION
The current implementation cannot handle this correctly, so just
forbid it for now.

GENERATED clauses must be attached to the column definition and cannot
be added later like DEFAULT, so if a child table has a generation
expression that the parent does not have, the child column will
necessarily be an attlocal column.  So to implement ALTER TABLE ONLY /
DROP EXPRESSION, we'd need extra code to update attislocal of the
direct child tables, somewhat similar to how DROP COLUMN does it, so
that the resulting state can be properly dumped and restored.

Discussion: https://www.postgresql.org/message-id/flat/15830.1575468847%40sss.pgh.pa.us
2020-11-03 15:28:36 +01:00
Alvaro Herrera 272bff6a35
Accept relations of any kind in LOCK TABLE
The restriction that only tables and views can be locked by LOCK TABLE
is quite arbitrary, since the underlying mechanism can lock any relation
type.  Drop the restriction so that programs such as pg_dump can lock
all relations they're interested in, preventing schema changes that
could cause a dump to fail after expending much effort.

Backpatch to 9.5.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Wells Oliver <wells.oliver@gmail.com>
Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql
2020-10-27 13:49:19 -03:00
Tom Lane d88d8ad284 Fix corner case for a BEFORE ROW UPDATE trigger returning OLD.
If the old row has any "missing" attributes that are supposed to
be retrieved from an associated tuple descriptor, the wrong things
happened because the trigger result is shoved directly into an
executor slot that lacks the missing-attribute data.  Notably,
CHECK-constraint verification would incorrectly see those columns
as NULL, and so would RETURNING-list evaluation.

Band-aid around this by forcibly expanding the tuple before passing
it to the trigger function.  (IMO it was a fundamental misdesign to
put the missing-attribute data into tuple constraints, which so
much of the system considers to be optional.  But we're probably
stuck with that now, and will have to continue to apply band-aids
as we find other places with similar issues.)

Back-patch to v12.  v11 would also have the issue, except that
commit 920311ab1 already applied a similar band-aid.  That forced
expansion in more cases than seem really necessary, though, so
this isn't a directly equivalent fix.

Amit Langote, with some cosmetic changes by me

Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
2020-10-25 13:57:46 -04:00
Tom Lane e4538708d5 Fix broken XML formatting in EXPLAIN output for incremental sorts.
The ExplainCloseGroup arguments for incremental sort usage data
didn't match the corresponding ExplainOpenGroup.  This only matters
for XML-format output, which is probably why we'd not noticed.

Daniel Gustafsson, per bug #16683 from Frits Jalvingh

Discussion: https://postgr.es/m/16683-8005033324ad34e9@postgresql.org
2020-10-23 11:32:33 -04:00
Alvaro Herrera 5f6463a20a
Fix ALTER TABLE .. ENABLE/DISABLE TRIGGER recursion
More precisely, correctly handle the ONLY flag indicating not to
recurse.  This was implemented in 86f575948c by recursing in
trigger.c, but that's the wrong place; use ATSimpleRecursion instead,
which behaves properly.  However, because legacy inheritance has never
recursed in that situation, make sure to do that only for new-style
partitioning.

I noticed this problem while testing a fix for another bug in the
vicinity.

This has been wrong all along, so backpatch to 11.

Discussion: https://postgr.es/m/20201016235925.GA29829@alvherre.pgsql
2020-10-20 19:22:09 -03:00
Alvaro Herrera 49433744ff
Reword partitioning error message
The error message about columns in the primary key not including all of
the partition key was unclear; reword it.

Backpatch all the way to pg11, where it appeared.

Reported-by: Nagaraj Raj <nagaraj.sf@yahoo.com>
Discussion: https://postgr.es/m/64062533.78364.1601415362244@mail.yahoo.com
2020-09-30 18:25:22 -03:00
Michael Paquier 1aedaba78a Fix progress reporting of REINDEX CONCURRENTLY
This addresses a couple of issues with the so-said subject:
- Report the correct parent relation with the index actually being
rebuilt or validated.  Previously, the command status remained set to
the last index created for the progress of the index build and
validation, which would be incorrect when working on a table that has
more than one index.
- Use the correct phase when waiting before the drop of the old
indexes.  Previously, this was reported with the same status as when
waiting before the old indexes are marked as dead.

Author: Matthias van de Meent, Michael Paquier
Discussion: https://postgr.es/m/CAEze2WhqFgcwe1_tv=sFYhLWV2AdpfukumotJ6JNcAOQs3jufg@mail.gmail.com
Backpatch-through: 12
2020-09-29 14:16:12 +09:00
Tom Lane 67b2ceea01 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 20:32:53 -04:00
Tom Lane f7873900f3 Revise RelationBuildRowSecurity() to avoid memory leaks.
This function leaked some memory while loading qual clauses for
an RLS policy.  While ordinarily negligible, that could build up
in some repeated-reload cases, as reported by Konstantin Knizhnik.
We can improve matters by borrowing the coding long used in
RelationBuildRuleLock: build stringToNode's result directly in
the target context, and remember to explicitly pfree the
input string.

This patch by no means completely guarantees zero leaks within
this function, since we have no real guarantee that the catalog-
reading subroutines it calls don't leak anything.  However,
practical tests suggest that this is enough to resolve the issue.
In any case, any remaining leaks are similar to those risked by
RelationBuildRuleLock and other relcache-loading subroutines.
If we need to fix them, we should adopt a more global approach
such as that used by the RECOVER_RELATION_BUILD_MEMORY hack.

While here, let's remove the need for an expensive PG_TRY block by
using MemoryContextSetParent to reparent an initially-short-lived
context for the RLS data.

Back-patch to all supported branches.

Discussion: https://postgr.es/m/21356c12-8917-8249-b35f-1c447231922b@postgrespro.ru
2020-09-26 16:04:06 -04:00
Tom Lane 17280b31c2 Avoid unnecessary recursion to child tables in ALTER TABLE SET NOT NULL.
If a partitioned table's column is already marked NOT NULL, there is
no need to examine its partitions, because we can rely on previous
DDL to have enforced that the child columns are NOT NULL as well.
(Unfortunately, the same cannot be said for traditional inheritance,
so for now we have to restrict the optimization to partitioned tables.)
Hence, we may skip recursing to child tables in this situation.

The reason this case is worth worrying about is that when pg_dump dumps
a partitioned table having a primary key, it will include the requisite
NOT NULL markings in the CREATE TABLE commands, and then add the
primary key as a separate step.  The primary key addition generates a
SET NOT NULL as a subcommand, just to be sure.  So the situation where
a SET NOT NULL is redundant does arise in the real world.

Skipping the recursion does more than just save a few cycles: it means
that a command such as "ALTER TABLE ONLY partition_parent ADD PRIMARY
KEY" will take locks only on the partition parent table, not on the
partitions.  It turns out that parallel pg_restore is effectively
assuming that that's true, and has little choice but to do so because
the dependencies listed for such a TOC entry don't include the
partitions.  pg_restore could thus issue this ALTER while data restores
on the partitions are still in progress.  Taking unnecessary locks on
the partitions not only hurts concurrency, but can lead to actual
deadlock failures, as reported by Domagoj Smoljanovic.

(A contributing factor in the deadlock is that TRUNCATE on a child
partition wants a non-exclusive lock on the parent.  This seems
likewise unnecessary, but the fix for it is more invasive so we
won't consider back-patching it.  Fortunately, getting rid of one
of these two poor behaviors is enough to remove the deadlock.)

Although support for partitioned primary keys came in with v11,
this patch is dependent on the SET NOT NULL refactoring done by
commit f4a3fdfbd, so we can only patch back to v12.

Patch by me; thanks to Alvaro Herrera and Amit Langote for review.

Discussion: https://postgr.es/m/VI1PR03MB31670CA1BD9625C3A8C5DD05EB230@VI1PR03MB3167.eurprd03.prod.outlook.com
2020-09-16 13:38:26 -04:00
Alvaro Herrera 873cb8fca9
Fix use-after-free bug with event triggers in an extension script
ALTER TABLE commands in an extension script are added to an event
trigger command list; but starting with commit b5810de3f4 they do so in
a memory context that's too short-lived, so when execution ends and time
comes to use the entries, they've already been freed.

(This would also be a problem with ALTER TABLE commands in a
multi-command query string, but these serendipitously end in
PortalContext -- which probably explains why it took so long for this to
be reported.)

Fix by using the memory context specifically set for that, instead.

Backpatch to 13, where the aforementioned commit appeared.

Reported-by: Philippe Beaudoin
Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://postgr.es/m/20200902193715.6e0269d4@firost
2020-09-15 21:03:14 -03:00
Peter Eisentraut b1b53f15bb Message fixes and style improvements 2020-09-14 06:42:07 +02:00
Alvaro Herrera 15dad57765
Raise error on concurrent drop of partitioned index
We were already raising an error for DROP INDEX CONCURRENTLY on a
partitioned table, albeit a different and confusing one:
  ERROR:  DROP INDEX CONCURRENTLY must be first action in transaction

Change that to throw a more comprehensible error:
  ERROR:  cannot drop partitioned index \"%s\" concurrently

Michael Paquier authored the test case for indexes on temporary
partitioned tables.

Backpatch to 11, where indexes on partitioned tables were added.

Reported-by: Jan Mussler <jan.mussler@zalando.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/16594-d2956ca909585067@postgresql.org
2020-09-01 13:40:43 -04:00
Tom Lane 47de6ac11b Fix ALTER TABLE's scheduling rules for AT_AddConstraint subcommands.
Commit 1281a5c90 rearranged the logic in this area rather drastically,
and it broke the case of adding a foreign key constraint in the same
ALTER that adds the pkey or unique constraint it depends on.  While
self-referential fkeys are surely a pretty niche case, this used to
work so we shouldn't break it.

To fix, reorganize the scheduling rules in ATParseTransformCmd so
that a transformed AT_AddConstraint subcommand will be delayed into
a later pass in all cases, not only when it's been spit out as a
side-effect of parsing some other command type.

Also tweak the logic so that we won't run ATParseTransformCmd twice
while doing this.  It seems to work even without that, but it's
surely wasting cycles to do so.

Per bug #16589 from Jeremy Evans.  Back-patch to v13 where the new
code was introduced.

Discussion: https://postgr.es/m/16589-31c8d981ca503896@postgresql.org
2020-08-22 12:34:17 -04:00
Tom Lane 894f5dea76 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 15:00:48 -04:00
Fujii Masao 674899ae02 Rework EXPLAIN for planner's buffer usage.
Commit ce77abe63c allowed EXPLAIN (BUFFERS) to report the information
on buffer usage during planning phase. However three issues were
reported regarding this feature.

(1) Previously, EXPLAIN option BUFFERS required ANALYZE. So the query
    had to be actually executed by specifying ANALYZE even when we
    want to see only the planner's buffer usage. This was inconvenient
    especially when the query was write one like DELETE.

(2) EXPLAIN included the planner's buffer usage in summary
    information. So SUMMARY option had to be enabled to report that.
    Also this format was confusing.

(3) The output structure for planning information was not consistent
    between TEXT format and the others. For example, "Planning" tag
    was output in JSON format, but not in TEXT format.

For (1), this commit allows us to perform EXPLAIN (BUFFERS) without
ANALYZE to report the planner's buffer usage.

For (2), this commit changed EXPLAIN output so that the planner's
buffer usage is reported before summary information.

For (3), this commit made the output structure for planning
information more consistent between the formats.

Back-patch to v13 where the planner's buffer usage was allowed to
be reported in EXPLAIN.

Reported-by: Pierre Giraud, David Rowley
Author: Fujii Masao
Reviewed-by: David Rowley, Julien Rouhaud, Pierre Giraud
Discussion: https://postgr.es/m/07b226e6-fa49-687f-b110-b7c37572f69e@dalibo.com
2020-08-21 20:50:01 +09:00
Noah Misch 592a589a04 Prevent concurrent SimpleLruTruncate() for any given SLRU.
The SimpleLruTruncate() header comment states the new coding rule.  To
achieve this, add locktype "frozenid" and two LWLocks.  This closes a
rare opportunity for data loss, which manifested as "apparent
wraparound" or "could not access status of transaction" errors.  Data
loss is more likely in pg_multixact, due to released branches' thin
margin between multiStopLimit and multiWrapLimit.  If a user's physical
replication primary logged ":  apparent wraparound" messages, the user
should rebuild standbys of that primary regardless of symptoms.  At less
risk is a cluster having emitted "not accepting commands" errors or
"must be vacuumed" warnings at some point.  One can test a cluster for
this data loss by running VACUUM FREEZE in every database.  Back-patch
to 9.5 (all supported versions).

Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
2020-08-15 10:15:56 -07:00
Tom Lane 98ca64899c Make contrib modules' installation scripts more secure.
Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation.  While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script.  Therefore, make a number of changes
to make such situations more secure:

* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.

* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.

* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions.  This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.

* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths.  (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)

Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.

Also add documentation around these issues, to help extension authors
write secure installation scripts.

Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.

Security: CVE-2020-14350
2020-08-10 10:44:42 -04:00
David Rowley 05dfb81324 Fix bogus EXPLAIN output for Hash Aggregate
9bdb300de modified the EXPLAIN output for Hash Aggregate to show details
from parallel workers. However, it neglected to consider that a given
parallel worker may not have assisted with the given Hash Aggregate. This
can occur when workers fail to start or during Parallel Append with
enable_partitionwise_join enabled when only a single worker is working on
a non-parallel aware sub-plan. It could also happen if a worker simply
wasn't fast enough to get any work done before other processes went and
finished all the work.

The bogus output came from the fact that ExplainOpenWorker() skipped
showing any details for non-initialized workers but show_hashagg_info()
did show details from the worker.  This meant that the worker properties
that were shown were not properly attributed to the worker that they
belong to.

In passing, we also now don't show Hash Aggregate properties for the
leader process when it did not contribute any work to the Hash Aggregate.
This can occur either during Parallel Append when only a parallel worker
worked on a given sub plan or with parallel_leader_participation set to
off.  This aims to make the behavior of Hash Aggregate's EXPLAIN output
more similar to Sort's.

Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20200805012105.GZ28072%40telsasoft.com
Backpatch-through: 13, where the original breakage was introduced
2020-08-07 10:22:08 +12:00
David Rowley 22c105595f Use int64 instead of long in incremental sort code
Windows 64bit has 4-byte long values which is not suitable for tracking
disk space usage in the incremental sort code. Let's just make all these
fields int64s.

Author: James Coleman
Discussion: https://postgr.es/m/CAApHDvpky%2BUhof8mryPf5i%3D6e6fib2dxHqBrhp0Qhu0NeBhLJw%40mail.gmail.com
Backpatch-through: 13, where the incremental sort code was added
2020-08-02 14:23:57 +12:00
Tom Lane 5c439f189b Fix oversight in ALTER TYPE: typmodin/typmodout must propagate to arrays.
If a base type supports typmods, its array type does too, with the
same interpretation.  Hence changes in pg_type.typmodin/typmodout
must be propagated to the array type.

While here, improve AlterTypeRecurse to not recurse to domains if
there is nothing we'd need to change.

Oversight in fe30e7ebf.  Back-patch to v13 where that came in.
2020-07-31 17:11:28 -04:00
David Rowley a57c837e5c Make EXPLAIN ANALYZE of HashAgg more similar to Hash Join
There were various unnecessary differences between Hash Agg's EXPLAIN
ANALYZE output and Hash Join's.  Here we modify the Hash Agg output so
that it's better aligned to Hash Join's.

The following changes have been made:
1. Start batches counter at 1 instead of 0.
2. Always display the "Batches" property, even when we didn't spill to
   disk.
3. Use the text "Batches" instead of "HashAgg Batches" for text format.
4. Use the text "Memory Usage" instead of "Peak Memory Usage" for text
   format.
5. Include "Batches" before "Memory Usage" in both text and non-text
   formats.

In passing also modify the "Planned Partitions" property so that we show
it regardless of if the value is 0 or not for non-text EXPLAIN formats.
This was pointed out by Justin Pryzby and probably should have been part
of 40efbf870.

Reviewed-by: Justin Pryzby, Jeff Davis
Discussion: https://postgr.es/m/CAApHDvrshRnA6C0VFnu7Fb9TVvgGo80PUMm5+2DiaS1gEkPvtw@mail.gmail.com
Backpatch-through: 13, where HashAgg batching was introduced
2020-07-29 11:43:11 +12:00
David Rowley b827304291 Fix timing issue with ALTER TABLE's validate constraint
An ALTER TABLE to validate a foreign key in which another subcommand
already caused a pending table rewrite could fail due to ALTER TABLE
attempting to validate the foreign key before the actual table rewrite
takes place.  This situation could result in an error such as:

ERROR:  could not read block 0 in file "base/nnnnn/nnnnn": read only 0 of 8192 bytes

The failure here was due to the SPI call which validates the foreign key
trying to access an index which is yet to be rebuilt.

Similarly, we also incorrectly tried to validate CHECK constraints before
the heap had been rewritten.

The fix for both is to delay constraint validation until phase 3, after
the table has been rewritten.  For CHECK constraints this means a slight
behavioral change.  Previously ALTER TABLE VALIDATE CONSTRAINT on
inheritance tables would be validated from the bottom up.  This was
different from the order of evaluation when a new CHECK constraint was
added.  The changes made here aligns the VALIDATE CONSTRAINT evaluation
order for inheritance tables to be the same as ADD CONSTRAINT, which is
generally top-down.

Reported-by: Nazli Ugur Koyluoglu, using SQLancer
Discussion: https://postgr.es/m/CAApHDvp%3DZXv8wiRyk_0rWr00skhGkt8vXDrHJYXRMft3TjkxCA%40mail.gmail.com
Backpatch-through: 9.5 (all supported versions)
2020-07-14 16:57:41 +12:00
David Rowley 285da44a69 Fix whitespace in HashAgg EXPLAIN ANALYZE
The Sort node does not put a space between the number of kilobytes and
the "kB" of memory or disk space used, but HashAgg does.  Here we align
HashAgg to do the same as Sort.  Sort has been displaying this
information for longer than HashAgg, so it makes sense to align HashAgg
to Sort rather than the other way around.

Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20200708163021.GW4107@telsasoft.com
Backpatch-through: 13, where the hashagg started showing these details
2020-07-09 10:07:00 +12:00
Tom Lane cfe89f5e6b Fix temporary tablespaces for shared filesets some more.
Commit ecd9e9f0b fixed the problem in the wrong place, causing unwanted
side-effects on the behavior of GetNextTempTableSpace().  Instead,
let's make SharedFileSetInit() responsible for subbing in the value
of MyDatabaseTableSpace when the default tablespace is called for.

The convention about what is in the tempTableSpaces[] array is
evidently insufficiently documented, so try to improve that.

It also looks like SharedFileSetInit() is doing the wrong thing in the
case where temp_tablespaces is empty.  It was hard-wiring use of the
pg_default tablespace, but it seems like using MyDatabaseTableSpace
is more consistent with what happens for other temp files.

Back-patch the reversion of PrepareTempTablespaces()'s behavior to
9.5, as ecd9e9f0b was.  The changes in SharedFileSetInit() go back
to v11 where that was introduced.  (Note there is net zero code change
before v11 from these two patch sets, so nothing to release-note.)

Magnus Hagander and Tom Lane

Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com
2020-07-03 17:01:34 -04:00
Magnus Hagander 1d94c39654 Fix temporary tablespaces for shared filesets
A likely copy/paste error in 98e8b48053 from  back in 2004 would
cause temp tablespace to be reset to InvalidOid if temp_tablespaces
was set to the same value as the primary tablespace in the database.
This would cause shared filesets (such as for parallel hash joins)
to ignore them, putting the temporary files in the default tablespace
instead of the configured one. The bug is in the old code, but it
appears to have been exposed only once we had shared filesets.

Reviewed-By: Daniel Gustafsson
Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com
Backpatch-through: 9.5
2020-07-03 15:10:12 +02:00
David Rowley d73e9a57bf Further adjustments to Hashagg EXPLAIN ANALYZE output
The "Disk Usage" and "HashAgg Batches" properties in the EXPLAIN ANALYZE
output for HashAgg were previously only shown if the number of batches
was greater than 0.  Here we change this so that these properties are
always shown for EXPLAIN ANALYZE formats other than "text".  The idea here
is that since the HashAgg could have spilled to disk if there had been
more data or groups to aggregate, then it's relevant that we're clear in
the EXPLAIN ANALYZE output when no spilling occurred in this particular
execution of the given plan.

For the "text" EXPLAIN format, we still hide these properties when no
spilling occurs.  This EXPLAIN format is designed to be easy for humans
to read.  To maintain the readability we have a higher threshold for which
properties we display for this format.

Discussion: https://postgr.es/m/CAApHDvo_dmNozQQTmN-2jGp1vT%3Ddxx7Q0vd%2BMvD1cGpv2HU%3DSg%40mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.
2020-07-01 12:16:42 +12:00
Tom Lane 57f8b9913b Undo double-quoting of index names in non-text EXPLAIN output formats.
explain_get_index_name() applied quote_identifier() to the index name.
This is fine for text output, but the non-text output formats all have
their own quoting conventions and would much rather start from the
actual index name.  For example in JSON you'd get something like

       "Index Name": "\"My Index\"",

which is surely not desirable, especially when the same does not
happen for table names.  Hence, move the responsibility for applying
quoting out to the callers, where it can go into already-existing
special code paths for text format.

This changes the API spec for users of explain_get_index_name_hook:
before, they were supposed to apply quote_identifier() if necessary,
now they should not.  Research suggests that the only publicly
available user of the hook is hypopg, and it actually forgot to
apply quoting anyway, so it's fine.  (In any case, there's no
behavioral change for the output of a hook as seen in non-text
EXPLAIN formats, so this won't break any case that programs should
be relying on.)

Digging in the commit logs, it appears that quoting was included in
explain_get_index_name's duties when commit 604ffd280 invented it;
and that was fine at the time because we only had text output format.
This should have been rethought when non-text formats were invented,
but it wasn't.

This is a fairly clear bug for users of non-text EXPLAIN formats,
so back-patch to all supported branches.

Per bug #16502 from Maciek Sakrejda.  Patch by me (based on
investigation by Euler Taveira); thanks to Julien Rouhaud for review.

Discussion: https://postgr.es/m/16502-57bd1c9f913ed1d1@postgresql.org
2020-06-22 11:46:41 -04:00
David Rowley bdee4af8e0 Fix EXPLAIN ANALYZE for parallel HashAgg plans
Since 1f39bce02, HashAgg nodes have had the ability to spill to disk when
memory consumption exceeds work_mem. That commit added new properties to
EXPLAIN ANALYZE to show the maximum memory usage and disk usage, however,
it didn't quite go as far as showing that information for parallel
workers.  Since workers may have experienced something very different from
the main process, we should show this information per worker, as is done
in Sort.

Reviewed-by: Justin Pryzby
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/CAApHDvpEKbfZa18mM1TD7qV6PG+w97pwCWq5tVD0dX7e11gRJw@mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.
2020-06-19 17:25:07 +12:00
Peter Eisentraut a5202889b4 Spelling adjustments
similar to 0fd2a79a63
2020-06-09 10:42:28 +02:00
Peter Eisentraut 0fd2a79a63 Spelling adjustments 2020-06-07 15:06:51 +02:00
Heikki Linnakangas 5b1c61e8b8 Add missing error code to "cannot attach index ..." error.
ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE was used in an ereport with the
same message but different errdetail a few lines earlier, so use that
here as well.

Backpatch-through: 11
2020-05-28 12:37:00 +03:00
Michael Paquier a995b371ae Add missing invocations to object access hooks
The following commands have been missing calls to object access hooks
InvokeObjectPost{Create|Alter}Hook normally applied to all commands:
- ALTER RULE RENAME TO
- ALTER USER MAPPING
- CREATE ACCESS METHOD
- CREATE STATISTICS

Thanks also to Robert Haas for the discussion.

Author: Mark Dilger
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/435CD295-F409-44E0-91EC-DF32C7AFCD76@enterprisedb.com
2020-05-23 14:03:04 +09:00
Tom Lane fa27dd40d5 Run pgindent with new pg_bsd_indent version 2.1.1.
Thomas Munro fixed a longstanding annoyance in pg_bsd_indent, that
it would misformat lines containing IsA() macros on the assumption
that the IsA() call should be treated like a cast.  This improves
some other cases involving field/variable names that match typedefs,
too.  The only places that get worse are a couple of uses of the
OpenSSL macro STACK_OF(); we'll gladly take that trade-off.

Discussion: https://postgr.es/m/20200114221814.GA19630@alvherre.pgsql
2020-05-16 11:54:51 -04:00
Tom Lane 5da14938f7 Rename SLRU structures and associated LWLocks.
Originally, the names assigned to SLRUs had no purpose other than
being shmem lookup keys, so not a lot of thought went into them.
As of v13, though, we're exposing them in the pg_stat_slru view and
the pg_stat_reset_slru function, so it seems advisable to take a bit
more care.  Rename them to names based on the associated on-disk
storage directories (which fortunately we *did* think about, to some
extent; since those are also visible to DBAs, consistency seems like
a good thing).  Also rename the associated LWLocks, since those names
are likewise user-exposed now as wait event names.

For the most part I only touched symbols used in the respective modules'
SimpleLruInit() calls, not the names of other related objects.  This
renaming could have been taken further, and maybe someday we will do so.
But for now it seems undesirable to change the names of any globally
visible functions or structs, so some inconsistency is unavoidable.

(But I *did* terminate "oldserxid" with prejudice, as I found that
name both unreadable and not descriptive of the SLRU's contents.)

Table 27.12 needs re-alphabetization now, but I'll leave that till
after the other LWLock renamings I have in mind.

Discussion: https://postgr.es/m/28683.1589405363@sss.pgh.pa.us
2020-05-15 14:28:25 -04:00
Amit Kapila a9cf48a4cf Make COPY TO keep locks until the transaction end.
COPY TO released the ACCESS SHARE lock immediately when it was done rather
than holding on to it until the end of the transaction.

This breaks the case where a REPEATABLE READ transaction could see an
empty table if it repeats a COPY statement and somebody truncated the
table in the meantime.

Before 4dded12faa the lock was also released after COPY FROM, but the
commit failed to notice the irregularity in COPY TO.

This is old behavior but doesn't seem important enough to backpatch.

Author: Laurenz Albe, based on suggestion by Robert Haas and Tom Lane
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/7bcfc39d4176faf85ab317d0c26786953646a411.camel@cybertec.at
2020-05-15 08:10:00 +05:30
Michael Paquier ff87fabef2 Remove duplicated comment block in event_trigger.c
The reasons why event triggers are disabled in standalone mode are
documented in the code path of ddl_command_start, and other places
checking if standalone mode is enabled or not mention to refer to the
comment for ddl_command_start, except for table_rewrite that duplicated
the same explanation.

Reported-by: David G. Johnston
Discussion: https://postgr.es/m/CAKFQuwYqHtXpvr2mBJRwH9f+Y5y1GXw3rhbaAu0Dk2MoNevsmA@mail.gmail.com
2020-05-15 08:19:30 +09:00
Tom Lane 5cbfce562f Initial pgindent and pgperltidy run for v13.
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.

Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
2020-05-14 13:06:50 -04:00
Tom Lane 7fd89f4d7a Fix async.c to not register any SLRU stats counts in the postmaster.
Previously, AsyncShmemInit forcibly initialized the first page of the
async SLRU, to save dealing with that case in asyncQueueAddEntries.
But this is a poor tradeoff, since many installations do not ever use
NOTIFY; for them, expending those cycles in AsyncShmemInit is a
complete waste.  Besides, this only saves a couple of instructions
in asyncQueueAddEntries, which hardly seems likely to be measurable.

The real reason to change this now, though, is that now that we track
SLRU access stats, the existing code is causing the postmaster to
accumulate some access counts, which then get inherited into child
processes by fork(), messing up the statistics.  Delaying the
initialization into the first child that does a NOTIFY fixes that.

Hence, we can revert f3d23d83e, which was an incorrect attempt at
fixing that issue.  Also, add an Assert to pgstat.c that should
catch any future errors of the same sort.

Discussion: https://postgr.es/m/8367.1589391884@sss.pgh.pa.us
2020-05-13 22:48:26 -04:00
Alvaro Herrera 17cc133f01
Dial back -Wimplicit-fallthrough to level 3
The additional pain from level 4 is excessive for the gain.

Also revert all the source annotation changes to their original
wordings, to avoid back-patching pain.

Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
2020-05-13 15:31:14 -04:00
Alvaro Herrera 3e9744465d
Add -Wimplicit-fallthrough to CFLAGS and CXXFLAGS
Use it at level 4, a bit more restrictive than the default level, and
tweak our commanding comments to FALLTHROUGH.

(However, leave zic.c alone, since it's external code; to avoid the
warnings that would appear there, change CFLAGS for that file in the
Makefile.)

Author: Julien Rouhaud <rjuju123@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol
Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
2020-05-12 16:07:30 -04:00
Tomas Vondra 6a918c3ac8 Rework EXPLAIN format for incremental sort
The explain format used by incremental sort was somewhat inconsistent
with other nodes, making it harder to parse and understand. This commit
addresses that by

 - adding an extra space to better separate groups of values

 - using colons instead of equal signs to separate key/value

 - properly capitalizing first letter of a key

 - using separate lines for full and pre-sorted groups

These changes were proposed by Justin Pryzby and mostly copy the final
explain format used to report WAL usage.

Author: Justin Pryzby
Reviewed-by: James Coleman
Discussion: https://postgr.es/m/20200419023625.GP26953@telsasoft.com
2020-05-12 20:04:39 +02:00
Tomas Vondra 1a40d37a9f Fix typos and improve incremental sort comments
Author: Justin Pryzby, James Coleman
Discussion: https://postgr.es/m/20200419023625.GP26953@telsasoft.com
2020-05-12 19:37:13 +02:00
Tomas Vondra ebeb3dea77 Simplify show_incremental_sort_info a bit
Incremental sort always processes at least one full group group before
switching to prefix groups, so it's enough to check just the number of
full groups. There was no risk of division by zero due to the extra
condition, but it made the code harder to understand.

Reported-by: Ranier Vilela
Discussion: https://postgr.es/m/CAEudQAp+7qoS92-4V1vLChpdY3vEkLCbf+gye6P-4cirE-0z0A@mail.gmail.com
2020-05-09 19:41:42 +02:00
Peter Eisentraut 086ffddf36 Fix several DDL issues of generated columns versus inheritance
Several combinations of generated columns and inheritance in CREATE
TABLE were not handled correctly.  Specifically:

- Disallow a child column specifying a generation expression if the
  parent column is a generated column.  The child column definition
  must be unadorned and the parent column's generation expression will
  be copied.

- Prohibit a child column of a generated parent column specifying
  default values or identity.

- Allow a child column of a not-generated parent column specifying
  itself as a generated column.  This previously did not work, but it
  was possible to arrive at the state via other means (involving ALTER
  TABLE), so it seems sensible to support it.

Add tests for each case.  Also add documentation about the rules
involving generated columns and inheritance.

Discussion:
    https://www.postgresql.org/message-id/flat/15830.1575468847%40sss.pgh.pa.us
    https://www.postgresql.org/message-id/flat/2678bad1-048f-519a-ef24-b12962f41807%40enterprisedb.com
    https://www.postgresql.org/message-id/flat/CAJvUf_u4h0DxkCMCeEKAWCuzGUTnDP-G5iVmSwxLQSXn0_FWNQ%40mail.gmail.com
2020-05-08 11:31:57 +02:00
Peter Eisentraut 501e41dd3c Propagate ALTER TABLE ... SET STORAGE to indexes
When creating a new index, the attstorage setting of the table column
is copied to regular (non-expression) index columns.  But a later
ALTER TABLE ... SET STORAGE is not propagated to indexes, thus
creating an inconsistent and undumpable state.

Discussion: https://www.postgresql.org/message-id/flat/9765d72b-37c0-06f5-e349-2a580aafd989%402ndquadrant.com
2020-05-08 08:39:17 +02:00
Alvaro Herrera 5be594caf8
Heed lock protocol in DROP OWNED BY
We were acquiring object locks then deleting objects one by one, instead
of acquiring all object locks first, ignoring those that did not exist,
and then deleting all objects together.   The latter is the correct
protocol to use, and what this commits changes to code to do.  Failing
to follow that leads to "cache lookup failed for relation XYZ" error
reports when DROP OWNED runs concurrently with other DDL -- for example,
a session termination that removes some temp tables.

Author: Álvaro Herrera
Reported-by: Mithun Chicklore Yogendra (Mithun CY)
Reviewed-by: Ahsan Hadi, Tom Lane
Discussion: https://postgr.es/m/CADq3xVZTbzK4ZLKq+dn_vB4QafXXbmMgDP3trY-GuLnib2Ai1w@mail.gmail.com
2020-05-06 12:29:41 -04:00
Amit Kapila 69bfaf2e1d Change the display of WAL usage statistics in Explain.
In commit 33e05f89c5, we have added the option to display WAL usage
statistics in Explain and auto_explain.  The display format used two spaces
between each field which is inconsistent with Buffer usage statistics which
is using one space between each field.  Change the format to make WAL usage
statistics consistent with Buffer usage statistics.

This commit also changed the usage of "full page writes" to
"full page images" for WAL usage statistics to make it consistent with
other parts of code and docs.

Author: Julien Rouhaud, Amit Kapila
Reviewed-by: Justin Pryzby, Kyotaro Horiguchi and Amit Kapila
Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com
2020-05-05 08:00:53 +05:30
Andrew Gierth d9a4cce29d Fix error case for CREATE ROLE ... IN ROLE.
CreateRole() was passing a Value node, not a RoleSpec node, for the
newly-created role name when adding the role as a member of existing
roles for the IN ROLE syntax.

This mistake went unnoticed because the node in question is used only
for error messages and is not accessed on non-error paths.

In older pg versions (such as 9.5 where this was found), this results
in an "unexpected node type" error in place of the real error. That
node type check was removed at some point, after which the code would
accidentally fail to fail on 64-bit platforms (on which accessing the
Value node as if it were a RoleSpec would be mostly harmless) or give
an "unexpected role type" error on 32-bit platforms.

Fix the code to pass the correct node type, and add an lfirst_node
assertion just in case.

Per report on irc from user m1chelangelo.

Backpatch all the way, because this error has been around for a long
time.
2020-04-25 05:09:30 +01:00
David Rowley 9f2c4edec2 Remove bogus Assert in foreign key cloning code
This Assert was trying to ensure that the number of columns in the foreign
key being cloned was the same number of attributes in the parentRel.  Of
course, it's perfectly valid to have columns in the table which are not
part of the foreign key constraint. It appears that this Assert was
misunderstanding that.

Reported-by: Rajkumar Raghuwanshi
Reviewed-by: amul sul
Discussion: https://postgr.es/m/CAKcux6=z1dtiWw5BOpqDx-U6KTiq+zD0Y2m810zUtWL+giVXWA@mail.gmail.com
2020-04-22 22:12:19 +12:00
Alvaro Herrera afccd76f1c
Fix detaching partitions with cloned row triggers
When a partition is detached, any triggers that had been cloned from its
parent were not properly disentangled from its parent triggers.
This resulted in triggers that could not be dropped because they
depended on the trigger in the trigger in the no-longer-parent table:
  ALTER TABLE t DETACH PARTITION t1;
  DROP TRIGGER trig ON t1;
    ERROR:  cannot drop trigger trig on table t1 because trigger trig on table t requires it
    HINT:  You can drop trigger trig on table t instead.

Moreover the table can no longer be re-attached to its parent, because
the trigger name is already taken:
  ALTER TABLE t ATTACH PARTITION t1 FOR VALUES FROM (1)TO(2);
    ERROR:  trigger "trig" for relation "t1" already exists

The former is a bug introduced in commit 86f575948c.  (The latter is
not necessarily a bug, but it makes the bug more uncomfortable.)

To avoid the complexity that would be needed to tell whether the trigger
has a local definition that has to be merged with the one coming from
the parent table, establish the behavior that the trigger is removed
when the table is detached.

Backpatch to pg11.

Author: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/20200408152412.GZ2228@telsasoft.com
2020-04-21 13:57:00 -04:00
Alvaro Herrera 5fc703946b
Add ALTER .. NO DEPENDS ON
Commit f2fcad27d5 (9.6 era) added the ability to mark objects as
dependent an extension, but forgot to add a way for such dependencies to
be removed.  This commit fixes that oversight.

Strictly speaking this should be backpatched to 9.6, but due to lack of
demand we're not doing so at this time.

Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql
Reviewed-by: ahsan hadi <ahsan.hadi@gmail.com>
Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2020-04-20 13:42:12 -04:00
Amit Kapila 24d2d38b1e Fix the usage of parallel and full options of vacuum command.
Earlier we were inconsistent in allowing the usage of parallel and
full options.  Change it such that we disallow them only when they are
combined in a way that we don't support.

In passing, improve the comments in some of the existing tests of parallel
vacuum.

Reported-by: Tushar Ahuja
Author: Justin Pryzby, Amit Kapila
Reviewed-by: Sawada Masahiko, Michael Paquier, Mahendra Singh Thalor and
Amit Kapila
Discussion: https://postgr.es/m/58c8d171-e665-6fa3-a9d3-d9423b694dae%40enterprisedb.com
2020-04-16 10:55:02 +05:30
Amit Kapila a6fea120a7 Comments and doc fixes for commit 40d964ec99.
Reported-by: Justin Pryzby
Author: Justin Pryzby, with few changes by me
Reviewed-by: Amit Kapila and Sawada Masahiko
Discussion: https://postgr.es/m/20200322021801.GB2563@telsasoft.com
2020-04-14 08:10:27 +05:30
Amit Kapila ef08ca113f Cosmetic fixups for WAL usage work.
Reported-by: Justin Pryzby and Euler Taveira
Author: Justin Pryzby and Julien Rouhaud
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com
2020-04-13 15:31:16 +05:30
Tom Lane 969f9d0b4b Make EXPLAIN report maximum hashtable usage across multiple rescans.
Before discarding the old hash table in ExecReScanHashJoin, capture
its statistics, ensuring that we report the maximum hashtable size
across repeated rescans of the hash input relation.  We can repurpose
the existing code for reporting hashtable size in parallel workers
to help with this, making the patch pretty small.  This also ensures
that if rescans happen within parallel workers, we get the correct
maximums across all instances.

Konstantin Knizhnik and Tom Lane, per diagnosis by Thomas Munro
of a trouble report from Alvaro Herrera.

Discussion: https://postgr.es/m/20200323165059.GA24950@alvherre.pgsql
2020-04-11 12:39:19 -04:00
Michael Paquier dd0f37ecce Fix collection of typos and grammar mistakes in the tree
This fixes some comments and documentation new as of Postgres 13.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20200408165653.GF2228@telsasoft.com
2020-04-10 11:18:39 +09:00
Peter Eisentraut 83fd4532a7 Allow publishing partition changes via ancestors
To control whether partition changes are replicated using their own
identity and schema or an ancestor's, add a new parameter that can be
set per publication named 'publish_via_partition_root'.

This allows replicating a partitioned table into a different partition
structure on the subscriber.

Author: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Rafia Sabih <rafia.pghackers@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Petr Jelinek <petr@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+HiwqH=Y85vRK3mOdjEkqFK+E=ST=eQiHdpj43L=_eJMOOznQ@mail.gmail.com
2020-04-08 11:19:23 +02:00
Alexander Korotkov 1aac32df89 Revert 0f5ca02f53
0f5ca02f53 introduces 3 new keywords.  It appears to be too much for relatively
small feature.  Given now we past feature freeze, it's already late for
discussion of the new syntax.  So, revert.

Discussion: https://postgr.es/m/28209.1586294824%40sss.pgh.pa.us
2020-04-08 11:37:27 +03:00
Alexander Korotkov 0f5ca02f53 Implement waiting for given lsn at transaction start
This commit adds following optional clause to BEGIN and START TRANSACTION
commands.

  WAIT FOR LSN lsn [ TIMEOUT timeout ]

New clause pospones transaction start till given lsn is applied on standby.
This clause allows user be sure, that changes previously made on primary would
be visible on standby.

New shared memory struct is used to track awaited lsn per backend.  Recovery
process wakes up backend once required lsn is applied.

Author: Ivan Kartyshov, Anna Akenteva
Reviewed-by: Craig Ringer, Thomas Munro, Robert Haas, Kyotaro Horiguchi
Reviewed-by: Masahiko Sawada, Ants Aasma, Dmitry Ivanov, Simon Riggs
Reviewed-by: Amit Kapila, Alexander Korotkov
Discussion: https://postgr.es/m/0240c26c-9f84-30ea-fca9-93ab2df5f305%40postgrespro.ru
2020-04-07 23:51:10 +03:00
Tomas Vondra d22782a539 Minor improvements in Incremental Sort explain
Some places still used "Maximum" instead of "Peak" when displaying info
about sort space, so fix that. Also, add a comment clarifying why it's
correct to check the number of full/prefix sort groups.

Author: James Coleman
Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com
2020-04-07 18:25:13 +02:00
Tom Lane c7654f6a37 Fix representation of SORT_TYPE_STILL_IN_PROGRESS.
It turns out that the code did indeed rely on a zeroed
TuplesortInstrumentation.sortMethod field to indicate
"this worker never did anything", although it seems the
issue only comes up during certain race-condition-y cases.

Hence, rearrange the TuplesortMethod enum to restore
SORT_TYPE_STILL_IN_PROGRESS to having the value zero,
and add some comments reinforcing that that isn't optional.

Also future-proof a loop over the possible values of the enum.
sizeof(bits32) happened to be the correct limit value,
but only by purest coincidence.

Per buildfarm and local investigation.

Discussion: https://postgr.es/m/12222.1586223974@sss.pgh.pa.us
2020-04-06 22:22:13 -04:00
Tomas Vondra 4bea576b03 Use INT64_FORMAT when formatting int64 values in explain
Per report from lapwing.
2020-04-07 01:16:57 +02:00
Tomas Vondra 7d6d82a524 Fix show_incremental_sort_info with force_parallel_mode
When executed with force_parallel_mode=regress, the function was exiting
too early and thus failed to print the worker stats. Fixed by making it
more like show_sort_info.

Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com
2020-04-06 23:19:13 +02:00
Tomas Vondra d2d8a229bc Implement Incremental Sort
Incremental Sort is an optimized variant of multikey sort for cases when
the input is already sorted by a prefix of the requested sort keys. For
example when the relation is already sorted by (key1, key2) and we need
to sort it by (key1, key2, key3) we can simply split the input rows into
groups having equal values in (key1, key2), and only sort/compare the
remaining column key3.

This has a number of benefits:

- Reduced memory consumption, because only a single group (determined by
  values in the sorted prefix) needs to be kept in memory. This may also
  eliminate the need to spill to disk.

- Lower startup cost, because Incremental Sort produce results after each
  prefix group, which is beneficial for plans where startup cost matters
  (like for example queries with LIMIT clause).

We consider both Sort and Incremental Sort, and decide based on costing.

The implemented algorithm operates in two different modes:

- Fetching a minimum number of tuples without check of equality on the
  prefix keys, and sorting on all columns when safe.

- Fetching all tuples for a single prefix group and then sorting by
  comparing only the remaining (non-prefix) keys.

We always start in the first mode, and employ a heuristic to switch into
the second mode if we believe it's beneficial - the goal is to minimize
the number of unnecessary comparions while keeping memory consumption
below work_mem.

This is a very old patch series. The idea was originally proposed by
Alexander Korotkov back in 2013, and then revived in 2017. In 2018 the
patch was taken over by James Coleman, who wrote and rewrote most of the
current code.

There were many reviewers/contributors since 2013 - I've done my best to
pick the most active ones, and listed them in this commit message.

Author: James Coleman, Alexander Korotkov
Reviewed-by: Tomas Vondra, Andreas Karlsson, Marti Raudsepp, Peter Geoghegan, Robert Haas, Thomas Munro, Antonin Houska, Andres Freund, Alexander Kuzmenkov
Discussion: https://postgr.es/m/CAPpHfdscOX5an71nHd8WSUH6GNOCf=V7wgDaTXdDd9=goN-gfA@mail.gmail.com
Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com
2020-04-06 21:35:10 +02:00
Michael Paquier 8ef9451f58 Refactor cluster.c to use new routine get_index_isclustered()
This new cache lookup routine has been introduced in a40caf5, and more
code paths can directly use it.

Note that in cluster_rel(), the code was returning immediately if the
tuple's entry in pg_index for the clustered index was not valid.  This
commit changes the code so as a lookup error is raised instead,
something that could not happen from the start as we check for the
existence of the index beforehand, while holding an exclusive lock on
the parent table.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com
2020-04-06 11:44:23 +09:00
Amit Kapila 33e05f89c5 Add the option to report WAL usage in EXPLAIN and auto_explain.
This commit adds a new option WAL similar to existing option BUFFERS in the
EXPLAIN command.  This option allows to include information on WAL record
generation added by commit df3b181499 in EXPLAIN output.

This also allows the WAL usage information to be displayed via
the auto_explain module.  A new parameter auto_explain.log_wal controls
whether WAL usage statistics are printed when an execution plan is logged.
This parameter has no effect unless auto_explain.log_analyze is enabled.

Author: Julien Rouhaud
Reviewed-by: Dilip Kumar and Amit Kapila
Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com
2020-04-06 08:02:15 +05:30
Michael Paquier a40caf5f86 Preserve clustered index after rewrites with ALTER TABLE
A table rewritten by ALTER TABLE would lose tracking of an index usable
for CLUSTER.  This setting is tracked by pg_index.indisclustered and is
controlled by ALTER TABLE, so some extra work was needed to restore it
properly.  Note that ALTER TABLE only marks the index that can be used
for clustering, and does not do the actual operation.

Author: Amit Langote, Justin Pryzby
Reviewed-by: Ibrar Ahmed, Michael Paquier
Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com
Backpatch-through: 9.5
2020-04-06 11:03:49 +09:00
Noah Misch c6b92041d3 Skip WAL for new relfilenodes, under wal_level=minimal.
Until now, only selected bulk operations (e.g. COPY) did this.  If a
given relfilenode received both a WAL-skipping COPY and a WAL-logged
operation (e.g. INSERT), recovery could lose tuples from the COPY.  See
src/backend/access/transam/README section "Skipping WAL for New
RelFileNode" for the new coding rules.  Maintainers of table access
methods should examine that section.

To maintain data durability, just before commit, we choose between an
fsync of the relfilenode and copying its contents to WAL.  A new GUC,
wal_skip_threshold, guides that choice.  If this change slows a workload
that creates small, permanent relfilenodes under wal_level=minimal, try
adjusting wal_skip_threshold.  Users setting a timeout on COMMIT may
need to adjust that timeout, and log_min_duration_statement analysis
will reflect time consumption moving to COMMIT from commands like COPY.

Internally, this requires a reliable determination of whether
RollbackAndReleaseCurrentSubTransaction() would unlink a relation's
current relfilenode.  Introduce rd_firstRelfilenodeSubid.  Amend the
specification of rd_createSubid such that the field is zero when a new
rel has an old rd_node.  Make relcache.c retain entries for certain
dropped relations until end of transaction.

Bump XLOG_PAGE_MAGIC, since this introduces XLOG_GIST_ASSIGN_LSN.
Future servers accept older WAL, so this bump is discretionary.

Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert
Haas.  Heikki Linnakangas and Michael Paquier implemented earlier
designs that materially clarified the problem.  Reviewed, in earlier
designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane,
Fujii Masao, and Simon Riggs.  Reported by Martijn van Oosterhout.

Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-04-04 12:25:34 -07:00
Fujii Masao ce77abe63c Include information on buffer usage during planning phase, in EXPLAIN output, take two.
When BUFFERS option is enabled, EXPLAIN command includes the information
on buffer usage during each plan node, in its output. In addition to that,
this commit makes EXPLAIN command include also the information on
buffer usage during planning phase, in its output. This feature makes it
easier to discern the cases where lots of buffer access happen during
planning.

This commit revives the original commit ed7a509571 that was reverted by
commit 19db23bcbd. The original commit had to be reverted because
it caused the regression test failure on the buildfarm members prion and
dory. But since commit c0885c4c30 got rid of the caues of the test failure,
the original commit can be safely introduced again.

Author: Julien Rouhaud, slightly revised by Fujii Masao
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/16109-26a1a88651e90608@postgresql.org
2020-04-04 03:13:17 +09:00
Tom Lane 6dd9f35779 Fix bogus CALLED_AS_TRIGGER() defenses.
contrib/lo's lo_manage() thought it could use
trigdata->tg_trigger->tgname in its error message about
not being called as a trigger.  That naturally led to a core dump.

unique_key_recheck() figured it could Assert that fcinfo->context
is a TriggerData node in advance of having checked that it's
being called as a trigger.  That's harmless in production builds,
and perhaps not that easy to reach in any case, but it's logically
wrong.

The first of these per bug #16340 from William Crowell;
the second from manual inspection of other CALLED_AS_TRIGGER
call sites.

Back-patch the lo.c change to all supported branches, the
other to v10 where the thinko crept in.

Discussion: https://postgr.es/m/16340-591c7449dc7c8c47@postgresql.org
2020-04-03 11:24:56 -04:00
Fujii Masao 19db23bcbd Revert "Include information on buffer usage during planning phase, in EXPLAIN output."
This reverts commit ed7a509571.

Per buildfarm member prion.
2020-04-03 12:20:42 +09:00
Fujii Masao ed7a509571 Include information on buffer usage during planning phase, in EXPLAIN output.
When BUFFERS option is enabled, EXPLAIN command includes the information
on buffer usage during each plan node, in its output. In addition to that,
this commit makes EXPLAIN command include also the information on
buffer usage during planning phase, in its output. This feature makes it
easier to discern the cases where lots of buffer access happen during
planning.

Author: Julien Rouhaud, slightly revised by Fujii Masao
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/16109-26a1a88651e90608@postgresql.org
2020-04-03 11:27:09 +09:00
Tom Lane 501b018799 Check equality semantics for unique indexes on partitioned tables.
We require the partition key to be a subset of the set of columns
being made unique, so that physically-separate indexes on the different
partitions are sufficient to enforce the uniqueness constraint.

The existing code checked that the listed columns appear, but did not
inquire into the index semantics, which is a serious oversight given
that different index opclasses might enforce completely different
notions of uniqueness.

Ideally, perhaps, we'd just match the partition key opfamily to the
index opfamily.  But hash partitioning uses hash opfamilies which we
can't directly match to btree opfamilies.  Hence, look up the equality
operator in each family, and accept if it's the same operator.  This
should be okay in a fairly general sense, since the equality operator
ought to precisely represent the opfamily's notion of uniqueness.

A remaining weak spot is that we don't have a cross-index-AM notion of
which opfamily member is "equality".  But we know which one to use for
hash and btree AMs, and those are the only two that are relevant here
at present.  (Any non-core AMs that know how to enforce equality are
out of luck, for now.)

Back-patch to v11 where this feature was introduced.

Guancheng Luo, revised a bit by me

Discussion: https://postgr.es/m/D9C3CEF7-04E8-47A1-8300-CA1DCD5ED40D@gmail.com
2020-04-01 14:49:49 -04:00
Amit Kapila 2401d93718 Fix coverity complaint about commit 40d964ec99.
The coverity complained that dividing integer expressions and then
converting the integer quotient to type "double" would lose fractional
part.  Typecasting one of the arguments of expression with double should
fix the report.

Author: Mahendra Singh Thalor
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/20200329224818.6phnhv7o2q2rfovf@alap3.anarazel.de
2020-04-01 09:28:13 +05:30
Alexander Korotkov 02a5786df2 Improve error reporting in opclasscmds.c
This commit improves error reporting introduced by 911e702077.  It puts
argument of errmsg() to the single line for easier grepping source for error
text.  Also it improves wording of errhint().
2020-03-31 17:51:57 +03:00
Alexander Korotkov 911e702077 Implement operator class parameters
PostgreSQL provides set of template index access methods, where opclasses have
much freedom in the semantics of indexing.  These index AMs are GiST, GIN,
SP-GiST and BRIN.  There opclasses define representation of keys, operations on
them and supported search strategies.  So, it's natural that opclasses may be
faced some tradeoffs, which require user-side decision.  This commit implements
opclass parameters allowing users to set some values, which tell opclass how to
index the particular dataset.

This commit doesn't introduce new storage in system catalog.  Instead it uses
pg_attribute.attoptions, which is used for table column storage options but
unused for index attributes.

In order to evade changing signature of each opclass support function, we
implement unified way to pass options to opclass support functions.  Options
are set to fn_expr as the constant bytea expression.  It's possible due to the
fact that opclass support functions are executed outside of expressions, so
fn_expr is unused for them.

This commit comes with some examples of opclass options usage.  We parametrize
signature length in GiST.  That applies to multiple opclasses: tsvector_ops,
gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and
gist_hstore_ops.  Also we parametrize maximum number of integer ranges for
gist__int_ops.  However, the main future usage of this feature is expected
to be json, where users would be able to specify which way to index particular
json parts.

Catversion is bumped.

Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru
Author: Nikita Glukhov, revised by me
Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
2020-03-30 19:17:23 +03:00
Fujii Masao 6aba63ef3e Allow the planner-related functions and hook to accept the query string.
This commit adds query_string argument into the planner-related functions
and hook and allows us to pass the query string to them.

Currently there is no user of the query string passed. But the upcoming patch
for the planning counters will add the planning hook function into
pg_stat_statements and the function will need the query string. So this change
will be necessary for that patch.

Also this change is useful for some extensions that want to use the query
string in their planner hook function.

Author: Pascal Legrand, Julien Rouhaud
Reviewed-by: Yoshikazu Imai, Tom Lane, Fujii Masao
Discussion: https://postgr.es/m/CAOBaU_bU1m3_XF5qKYtSj1ua4dxd=FWDyh2SH4rSJAUUfsGmAQ@mail.gmail.com
Discussion: https://postgr.es/m/1583789487074-0.post@n3.nabble.com
2020-03-30 13:51:05 +09:00
Andres Freund cedffbdb8b Report wait event for cost-based vacuum delay.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20200321040750.GD13662@telsasoft.com
2020-03-23 22:53:22 -07:00
Jeff Davis 64fe602279 Fixes for Disk-based Hash Aggregation.
Justin Pryzby raised a couple issues with commit 1f39bce0. Fixed.

Also, tweak the way the size of a hash entry is estimated and the
number of buckets is estimated when calling BuildTupleHashTableExt().

Discussion: https://www.postgresql.org/message-id/20200319064222.GR26184@telsasoft.com
2020-03-23 15:43:07 -07:00
Amit Kapila 33753ac9d7 Add object names to partition integrity violations.
All errors of SQLSTATE class 23 should include the name of an object
associated with the error in separate fields of the error report message.
We do this so that applications need not try to extract them from the
possibly-localized human-readable text of the message.

Reported-by: Chris Bandy
Author: Chris Bandy
Reviewed-by: Amit Kapila and Amit Langote
Discussion: https://postgr.es/m/0aa113a3-3c7f-db48-bcd8-f9290b2269ae@gmail.com
2020-03-23 08:09:15 +05:30
Noah Misch de9396326e Revert "Skip WAL for new relfilenodes, under wal_level=minimal."
This reverts commit cb2fd7eac2.  Per
numerous buildfarm members, it was incompatible with parallel query, and
a test case assumed LP64.  Back-patch to 9.5 (all supported versions).

Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-22 09:24:09 -07:00
Noah Misch cb2fd7eac2 Skip WAL for new relfilenodes, under wal_level=minimal.
Until now, only selected bulk operations (e.g. COPY) did this.  If a
given relfilenode received both a WAL-skipping COPY and a WAL-logged
operation (e.g. INSERT), recovery could lose tuples from the COPY.  See
src/backend/access/transam/README section "Skipping WAL for New
RelFileNode" for the new coding rules.  Maintainers of table access
methods should examine that section.

To maintain data durability, just before commit, we choose between an
fsync of the relfilenode and copying its contents to WAL.  A new GUC,
wal_skip_threshold, guides that choice.  If this change slows a workload
that creates small, permanent relfilenodes under wal_level=minimal, try
adjusting wal_skip_threshold.  Users setting a timeout on COMMIT may
need to adjust that timeout, and log_min_duration_statement analysis
will reflect time consumption moving to COMMIT from commands like COPY.

Internally, this requires a reliable determination of whether
RollbackAndReleaseCurrentSubTransaction() would unlink a relation's
current relfilenode.  Introduce rd_firstRelfilenodeSubid.  Amend the
specification of rd_createSubid such that the field is zero when a new
rel has an old rd_node.  Make relcache.c retain entries for certain
dropped relations until end of transaction.

Back-patch to 9.5 (all supported versions).  This introduces a new WAL
record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC.  As
always, update standby systems before master systems.  This changes
sizeof(RelationData) and sizeof(IndexStmt), breaking binary
compatibility for affected extensions.  (The most recent commit to
affect the same class of extensions was
089e4d405d0f3b94c74a2c6a54357a84a681754b.)

Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert
Haas.  Heikki Linnakangas and Michael Paquier implemented earlier
designs that materially clarified the problem.  Reviewed, in earlier
designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane,
Fujii Masao, and Simon Riggs.  Reported by Martijn van Oosterhout.

Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-03-21 09:38:26 -07:00
Noah Misch e629a01f69 During heap rebuild, lock any TOAST index until end of transaction.
swap_relation_files() calls toast_get_valid_index() to find and lock
this index, just before swapping with the rebuilt TOAST index.  The
latter function releases the lock before returning.  Potential for
mischief is low; a concurrent session can issue ALTER INDEX ... SET
(fillfactor = ...), which is not alarming.  Nonetheless, changing
pg_class.relfilenode without a lock is unconventional.  Back-patch to
9.5 (all supported versions), because another fix needs this.

Discussion: https://postgr.es/m/20191226001521.GA1772687@rfd.leadboat.com
2020-03-21 09:38:26 -07:00
Tom Lane 24e2885ee3 Introduce "anycompatible" family of polymorphic types.
This patch adds the pseudo-types anycompatible, anycompatiblearray,
anycompatiblenonarray, and anycompatiblerange.  They work much like
anyelement, anyarray, anynonarray, and anyrange respectively, except
that the actual input values need not match precisely in type.
Instead, if we can find a common supertype (using the same rules
as for UNION/CASE type resolution), then the parser automatically
promotes the input values to that type.  For example,
"myfunc(anycompatible, anycompatible)" can match a call with one
integer and one bigint argument, with the integer automatically
promoted to bigint.  With anyelement in the definition, the user
would have had to cast the integer explicitly.

The new types also provide a second, independent set of type variables
for function matching; thus with "myfunc(anyelement, anyelement,
anycompatible) returns anycompatible" the first two arguments are
constrained to be the same type, but the third can be some other
type, and the result has the type of the third argument.  The need
for more than one set of type variables was foreseen back when we
first invented the polymorphic types, but we never did anything
about it.

Pavel Stehule, revised a bit by me

Discussion: https://postgr.es/m/CAFj8pRDna7VqNi8gR+Tt2Ktmz0cq5G93guc3Sbn_NVPLdXAkqA@mail.gmail.com
2020-03-19 11:43:11 -04:00
Jeff Davis 1f39bce021 Disk-based Hash Aggregation.
While performing hash aggregation, track memory usage when adding new
groups to a hash table. If the memory usage exceeds work_mem, enter
"spill mode".

In spill mode, new groups are not created in the hash table(s), but
existing groups continue to be advanced if input tuples match. Tuples
that would cause a new group to be created are instead spilled to a
logical tape to be processed later.

The tuples are spilled in a partitioned fashion. When all tuples from
the outer plan are processed (either by advancing the group or
spilling the tuple), finalize and emit the groups from the hash
table. Then, create new batches of work from the spilled partitions,
and select one of the saved batches and process it (possibly spilling
recursively).

Author: Jeff Davis
Reviewed-by: Tomas Vondra, Adam Lee, Justin Pryzby, Taylor Vesely, Melanie Plageman
Discussion: https://postgr.es/m/507ac540ec7c20136364b5272acbcd4574aa76ef.camel@j-davis.com
2020-03-18 15:42:02 -07:00
Alvaro Herrera 487e9861d0
Enable BEFORE row-level triggers for partitioned tables
... with the limitation that the tuple must remain in the same
partition.

Reviewed-by: Ashutosh Bapat
Discussion: https://postgr.es/m/20200227165158.GA2071@alvherre.pgsql
2020-03-18 18:58:05 -03:00
Michael Paquier fdeeb524b4 Fix typo in indexcmds.c
Introduced by 61d7c7b.

Backpatch-through: 12
2020-03-18 11:13:12 +09:00
Peter Eisentraut 1cc9c2412c Preserve replica identity index across ALTER TABLE rewrite
If an index was explicitly set as replica identity index, this setting
was lost when a table was rewritten by ALTER TABLE.  Because this
setting is part of pg_index but actually controlled by ALTER
TABLE (not part of CREATE INDEX, say), we have to do some extra work
to restore it.

Based-on-patch-by: Quan Zongliang <quanzongliang@gmail.com>
Reviewed-by: Euler Taveira <euler.taveira@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/c70fcab2-4866-0d9f-1d01-e75e189db342@gmail.com
2020-03-13 11:57:06 +01:00
Peter Eisentraut bf68b79e50 Refactor ps_status.c API
The init_ps_display() arguments were mostly lies by now, so to match
typical usage, just use one argument and let the caller assemble it
from multiple sources if necessary.  The only user of the additional
arguments is BackendInitialize(), which was already doing string
assembly on the caller side anyway.

Remove the second argument of set_ps_display() ("force") and just
handle that in init_ps_display() internally.

BackendInitialize() also used to set the initial status as
"authentication", but that was very far from where authentication
actually happened.  So now it's set to "initializing" and then
"authentication" just before the actual call to
ClientAuthentication().

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Kuntal Ghosh <kuntalghosh.2007@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/c65e5196-4f04-4ead-9353-6088c19615a3@2ndquadrant.com
2020-03-11 16:38:31 +01:00
Alvaro Herrera 899a04f5ed
Avoid duplicates in ALTER ... DEPENDS ON EXTENSION
If the command is attempted for an extension that the object already
depends on, silently do nothing.

In particular, this means that if a database containing multiple such
entries is dumped, the restore will silently do the right thing and
record just the first one.  (At least, in a world where pg_dump does
dump such entries -- which it doesn't currently, but it will.)

Backpatch to 9.6, where this kind of dependency was introduced.

Reviewed-by: Ibrar Ahmed, Tom Lane (offlist)
Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql
2020-03-11 11:04:59 -03:00
Tom Lane d01f03a495 Preserve integer and float values accurately in (de)serialize_deflist.
Previously, this code just smashed all types of DefElem values to
strings, cavalierly reasoning that nobody would care.  But in point of
fact, most of the defGetFoo functions do distinguish among different
input syntaxes; for instance defGetBoolean will accept 1 as an integer
but not "1" as a string.  This led to CREATE/ALTER TEXT SEARCH
DICTIONARY accepting 0 and 1 as values for boolean dictionary
properties, only to have the dictionary fail at runtime.

We can upgrade this behavior by teaching serialize_deflist that it
does not need to quote T_Integer or T_Float nodes' values on output,
and then teaching deserialize_deflist to restore unquoted integer or
float values as the appropriate node type.  This should not break
anything using pg_ts_dict.dictinitoption, since that field is just
defined as being something valid to include in CREATE TEXT SEARCH
DICTIONARY.

deserialize_deflist is also used to parse the options arguments
for the ts_headline family of functions, but so far as I can see
this won't cause any problems there either: the only consumer of
that output is prsd_headline which always uses defGetString.
(Really that's a bad idea, but I won't risk changing it here.)

This is surely a bug fix, but given the lack of field complaints
I don't think it's necessary to back-patch.

Discussion: https://postgr.es/m/CAMkU=1xRcs_BUPzR0+V3WndaCAv0E_m3h6aUEJ8NF-sY1nnHsw@mail.gmail.com
2020-03-10 12:30:02 -04:00
Alvaro Herrera 40b3e2c201
Split out CreateCast into src/backend/catalog/pg_cast.c
This catalog-handling code was previously together with the rest of
CastCreate() in src/backend/commands/functioncmds.c.  A future patch
will need a way to add casts internally, so this will be useful to have
separate.

Also, move the nearby get_cast_oid() function from functioncmds.c to
lsyscache.c, which seems a more natural place for it.

Author: Paul Jungwirth, minor edits by Álvaro
Discussion: https://postgr.es/m/20200309210003.GA19992@alvherre.pgsql
2020-03-10 11:28:23 -03:00
Peter Eisentraut 3c173a53a8 Remove utils/acl.h from catalog/objectaddress.h
The need for this was removed by
8b9e9644dc.

A number of files now need to include utils/acl.h or
parser/parse_node.h explicitly where they previously got it indirectly
somehow.

Since parser/parse_node.h already includes nodes/parsenodes.h, the
latter is then removed where the former was added.  Also, remove
nodes/pg_list.h from objectaddress.h, since that's included via
nodes/parsenodes.h.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/7601e258-26b2-8481-36d0-dc9dca6f28f1%402ndquadrant.com
2020-03-10 10:27:00 +01:00
Peter Eisentraut 17b9e7f9fe Support adding partitioned tables to publication
When a partitioned table is added to a publication, changes of all of
its partitions (current or future) are published via that publication.

This change only affects which tables a publication considers as its
members.  The receiving side still sees the data coming from the
individual leaf partitions.  So existing restrictions that partition
hierarchies can only be replicated one-to-one are not changed by this.

Author: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Rafia Sabih <rafia.pghackers@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+HiwqH=Y85vRK3mOdjEkqFK+E=ST=eQiHdpj43L=_eJMOOznQ@mail.gmail.com
2020-03-10 09:09:32 +01:00
Michael Paquier 61d7c7bce3 Prevent reindex of invalid indexes on TOAST tables
Such indexes can only be duplicated leftovers of a previously failed
REINDEX CONCURRENTLY command, and a valid equivalent is guaranteed to
exist.  As toast indexes can only be dropped if invalid, reindexing
these would lead to useless duplicated indexes that can't be dropped
anymore, except if the parent relation is dropped.

Thanks to Justin Pryzby for reminding that this problem was reported
long ago during the review of the original patch of REINDEX
CONCURRENTLY, but the issue was never addressed.

Reported-by: Sergei Kornilov, Justin Pryzby
Author: Julien Rouhaud
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/36712441546604286%40sas1-890ba5c2334a.qloud-c.yandex.net
Discussion: https://postgr.es/m/20200216190835.GA21832@telsasoft.com
Backpatch-through: 12
2020-03-10 15:38:17 +09:00
Peter Eisentraut 71d60e2aa0 Add tg_updatedcols to TriggerData
This allows a trigger function to determine for an UPDATE trigger
which columns were actually updated.  This allows some optimizations
in generic trigger functions such as lo_manage and
tsvector_update_trigger.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/flat/11c5f156-67a9-0fb5-8200-2a8018eb2e0c@2ndquadrant.com
2020-03-09 09:34:55 +01:00
Peter Eisentraut 8f152b6c50 Code simplification
Initialize TriggerData to 0 for the whole struct together, instead of
each field separately.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/flat/11c5f156-67a9-0fb5-8200-2a8018eb2e0c@2ndquadrant.com
2020-03-09 09:34:55 +01:00
Tom Lane fe30e7ebfa Allow ALTER TYPE to change some properties of a base type.
Specifically, this patch allows ALTER TYPE to:
* Change the default TOAST strategy for a toastable base type;
* Promote a non-toastable type to toastable;
* Add/remove binary I/O functions for a type;
* Add/remove typmod I/O functions for a type;
* Add/remove a custom ANALYZE statistics functions for a type.

The first of these can be done by the type's owner; all the others
require superuser privilege since misuse could cause problems.

The main motivation for this patch is to allow extensions to
upgrade the feature sets of their data types, so the set of
alterable properties is biased towards that use-case.  However
it's also true that changing some other properties would be
a lot harder, as they get baked into physical storage and/or
stored expressions that depend on the type.

Along the way, refactor GenerateTypeDependencies() to make it easier
to call, refactor DefineType's volatility checks so they can be shared
by AlterType, and teach typcache.c that it might have to reload data
from the type's pg_type row, a scenario it never handled before.
Also rearrange alter_type.sgml a bit for clarity (put the
composite-type operations together).

Tomas Vondra and Tom Lane

Discussion: https://postgr.es/m/20200228004440.b23ein4qvmxnlpht@development
2020-03-06 12:19:29 -05:00
Tom Lane bb03010b9f Remove the "opaque" pseudo-type and associated compatibility hacks.
A long time ago, it was necessary to declare datatype I/O functions,
triggers, and language handler support functions in a very type-unsafe
way involving a single pseudo-type "opaque".  We got rid of those
conventions in 7.3, but there was still support in various places to
automatically convert such functions to the modern declaration style,
to be able to transparently re-load dumps from pre-7.3 servers.
It seems unnecessary to continue to support that anymore, so take out
the hacks; whereupon the "opaque" pseudo-type itself is no longer
needed and can be dropped.

This is part of a group of patches removing various server-side kluges
for transparently upgrading pre-8.0 dump files.  Since we've had few
complaints about dropping pg_dump's support for dumping from pre-8.0
servers (commit 64f3524e2), it seems okay to now remove these kluges.

Discussion: https://postgr.es/m/4110.1583255415@sss.pgh.pa.us
2020-03-05 15:48:56 -05:00
Tom Lane 84eca14bc4 Remove ancient hacks to ignore certain opclass names in CREATE INDEX.
Twenty years ago, we removed certain operator classes in favor of
letting indexes over their data types be built with some other
binary-compatible, more standard opclass.  As a hack to allow existing
index definitions to be dumped and reloaded, we made CREATE INDEX ignore
the removed opclass names, so that such indexes would fall back to the
new default opclass for their data types.  This was never intended to
be a long-lived thing; it carries the obvious risk of breaking some
future developer's attempt to re-use those old opclass names.  Since
all of the cases in question are for opclasses that were removed
before PG 8.0, it seems okay to get rid of these hacks now.

This is part of a group of patches removing various server-side kluges
for transparently upgrading pre-8.0 dump files.  Since we've had few
complaints about dropping pg_dump's support for dumping from pre-8.0
servers (commit 64f3524e2), it seems okay to now remove these kluges.

Discussion: https://postgr.es/m/3685.1583422389@sss.pgh.pa.us
2020-03-05 15:36:06 -05:00
Tom Lane e58a599752 Remove ancient support for upgrading pre-7.3 foreign key constraints.
Before 7.3, foreign key constraints had no explicit catalog
representation, so that what pg_dump produced for them was (usually)
a set of three CREATE CONSTRAINT TRIGGER commands.  Commit a2899ebdc
and some follow-on fixes added an ugly hack in CreateTrigger() to
recognize that pattern and reconstruct the foreign key definition.
However, we've never had any test coverage for that code, so that it's
legitimate to wonder if it still works; and having to maintain it in
the face of upcoming trigger-related patches seems rather pointless.
Let's decree that its time has passed, and drop it.

This is part of a group of patches removing various server-side kluges
for transparently upgrading pre-8.0 dump files.  Since we've had few
complaints about dropping pg_dump's support for dumping from pre-8.0
servers (commit 64f3524e2), it seems okay to now remove these kluges.

Daniel Gustafsson

Discussion: https://postgr.es/m/805874E2-999C-4CDA-856F-1AFBD9DFE933@yesql.se
2020-03-05 15:25:45 -05:00
Tom Lane 3ed2005ff5 Introduce macros for typalign and typstorage constants.
Our usual practice for "poor man's enum" catalog columns is to define
macros for the possible values and use those, not literal constants,
in C code.  But for some reason lost in the mists of time, this was
never done for typalign/attalign or typstorage/attstorage.  It's never
too late to make it better though, so let's do that.

The reason I got interested in this right now is the need to duplicate
some uses of the TYPSTORAGE constants in an upcoming ALTER TYPE patch.
But in general, this sort of change aids greppability and readability,
so it's a good idea even without any specific motivation.

I may have missed a few places that could be converted, and it's even
more likely that pending patches will re-introduce some hard-coded
references.  But that's not fatal --- there's no expectation that
we'd actually change any of these values.  We can clean up stragglers
over time.

Discussion: https://postgr.es/m/16457.1583189537@sss.pgh.pa.us
2020-03-04 10:34:25 -05:00
Alvaro Herrera 2f9661311b
Represent command completion tags as structs
The backend was using strings to represent command tags and doing string
comparisons in multiple places, but that's slow and unhelpful.  Create a
new command list with a supporting structure to use instead; this is
stored in a tag-list-file that can be tailored to specific purposes with
a caller-definable C macro, similar to what we do for WAL resource
managers.  The first first such uses are a new CommandTag enum and a
CommandTagBehavior struct.

Replace numerous occurrences of char *completionTag with a
QueryCompletion struct so that the code no longer stores information
about completed queries in a cstring.  Only at the last moment, in
EndCommand(), does this get converted to a string.

EventTriggerCacheItem no longer holds an array of palloc’d tag strings
in sorted order, but rather just a Bitmapset over the CommandTags.

Author: Mark Dilger, with unsolicited help from Álvaro Herrera
Reviewed-by: John Naylor, Tom Lane
Discussion: https://postgr.es/m/981A9DB4-3F0C-4DA5-88AD-CB9CFF4D6CAD@enterprisedb.com
2020-03-02 18:19:51 -03:00
Alvaro Herrera b9b408c487
Record parents of triggers
This let us get rid of a recently introduced ugly hack (commit
1fa846f1c9).

Author: Álvaro Herrera
Reviewed-by: Amit Langote, Tom Lane
Discussion: https://postgr.es/m/20200217215641.GA29784@alvherre.pgsql
2020-02-27 13:23:33 -03:00
Robert Haas 05d8449e73 Move src/backend/utils/hash/hashfn.c to src/common
This also involves renaming src/include/utils/hashutils.h, which
becomes src/include/common/hashfn.h. Perhaps an argument can be
made for keeping the hashutils.h name, but it seemed more
consistent to make it match the name of the file, and also more
descriptive of what is actually going on here.

Patch by me, reviewed by Suraj Kharage and Mark Dilger. Off-list
advice on how not to break the Windows build from Davinder Singh
and Amit Kapila.

Discussion: http://postgr.es/m/CA+TgmoaRiG4TXND8QuM6JXFRkM_1wL2ZNhzaUKsuec9-4yrkgw@mail.gmail.com
2020-02-27 09:25:41 +05:30
Peter Geoghegan 612a1ab767 Add equalimage B-Tree support functions.
Invent the concept of a B-Tree equalimage ("equality implies image
equality") support function, registered as support function 4.  This
indicates whether it is safe (or not safe) to apply optimizations that
assume that any two datums considered equal by an operator class's order
method must be interchangeable without any loss of semantic information.
This is static information about an operator class and a collation.

Register an equalimage routine for almost all of the existing B-Tree
opclasses.  We only need two trivial routines for all of the opclasses
that are included with the core distribution.  There is one routine for
opclasses that index non-collatable types (which returns 'true'
unconditionally), plus another routine for collatable types (which
returns 'true' when the collation is a deterministic collation).

This patch is infrastructure for an upcoming patch that adds B-Tree
deduplication.

Author: Peter Geoghegan, Anastasia Lubennikova
Discussion: https://postgr.es/m/CAH2-Wzn3Ee49Gmxb7V1VJ3-AC8fWn-Fr8pfWQebHe8rYRxt5OQ@mail.gmail.com
2020-02-26 11:28:25 -08:00
Tom Lane 70a7732007 Remove support for upgrading extensions from "unpackaged" state.
Andres Freund pointed out that allowing non-superusers to run
"CREATE EXTENSION ... FROM unpackaged" has security risks, since
the unpackaged-to-1.0 scripts don't try to verify that the existing
objects they're modifying are what they expect.  Just attaching such
objects to an extension doesn't seem too dangerous, but some of them
do more than that.

We could have resolved this, perhaps, by still requiring superuser
privilege to use the FROM option.  However, it's fair to ask just what
we're accomplishing by continuing to lug the unpackaged-to-1.0 scripts
forward.  None of them have received any real testing since 9.1 days,
so they may not even work anymore (even assuming that one could still
load the previous "loose" object definitions into a v13 database).
And an installation that's trying to go from pre-9.1 to v13 or later
in one jump is going to have worse compatibility problems than whether
there's a trivial way to convert their contrib modules into extension
style.

Hence, let's just drop both those scripts and the core-code support
for "CREATE EXTENSION ... FROM".

Discussion: https://postgr.es/m/20200213233015.r6rnubcvl4egdh5r@alap3.anarazel.de
2020-02-19 16:59:14 -05:00
Fujii Masao b7e51b350c Make inherited LOCK TABLE perform access permission checks on parent table only.
Previously, LOCK TABLE command through a parent table checked
the permissions on not only the parent table but also the children
tables inherited from it. This was a bug and inherited queries should
perform access permission checks on the parent table only. This
commit fixes LOCK TABLE so that it does not check the permission
on children tables.

This patch is applied only in the master branch. We decided not to
back-patch because it's not hard to imagine that there are some
applications expecting the old behavior and the change breaks their
security.

Author: Amit Langote
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAHGQGwE+GauyG7POtRfRwwthAGwTjPQYdFHR97+LzA4RHGnJxA@mail.gmail.com
2020-02-18 13:13:15 +09:00
Peter Eisentraut c6679e4fca Optimize update of tables with generated columns
When updating a table row with generated columns, only recompute those
generated columns whose base columns have changed in this update and
keep the rest unchanged.  This can result in a significant performance
benefit.  The required information was already kept in
RangeTblEntry.extraUpdatedCols; we just have to make use of it.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/b05e781a-fa16-6b52-6738-761181204567@2ndquadrant.com
2020-02-17 15:20:58 +01:00
Tom Lane faade5d4c6 Update obsolete comment.
Noted by Justin Pryzby, though I chose to just rip out the stale text,
as it's in no way relevant to this particular function.

Discussion: https://postgr.es/m/20200212182337.GZ1412@telsasoft.com
2020-02-15 15:22:40 -05:00
Tom Lane 0973f5602c Remove long-dead comments.
These should've been dropped by a8bb8eb58, but evidently were
missed.  Not important enough to back-patch.
2020-02-12 14:33:49 -05:00
Alvaro Herrera b048f558dd Fix priv checks for ALTER <object> DEPENDS ON EXTENSION
Marking an object as dependant on an extension did not have any
privilege check whatsoever; this allowed any user to mark objects as
droppable by anyone able to DROP EXTENSION, which could be used to cause
system-wide havoc.  Disallow by checking that the calling user owns the
mentioned object.

(No constraints are placed on the extension.)

Security: CVE-2020-1720
Reported-by: Tom Lane
Discussion: 31605.1566429043@sss.pgh.pa.us
2020-02-10 11:47:09 -03:00
Alvaro Herrera 55173d2e66 Fix failure to create FKs correctly in partitions
On a multi-level partioned table, when adding a partition not directly
connected to the root table, foreign key constraints referencing the
root were not cloned to the new partition, leading to the FK being
possibly inadvertently violated later on.

This was caused by fuzzy thinking in CloneFkReferenced (commit
f56f8f8da6): it was skipping constraints marked as having parents on
the theory that cloning those would create duplicates; but that's only
correct for the top level of the partitioning hierarchy.  For levels
below that one, such constraints must still be considered and only
skipped if later on we see that we'd create duplicates.  Apparently, I
(Álvaro) wrote the comments right but the code implemented something
slightly different.

Author: Jehan-Guillaume de Rorthais
Discussion: https://postgr.es/m/20200206004948.238352db@firost
2020-02-07 18:27:18 -03:00
Tom Lane 7d91b604d9 Fix handling of "Subplans Removed" field in EXPLAIN output.
Commit 499be013d added this field in a rather poorly-thought-through
manner, with the result being that rather than being a field of the
Append or MergeAppend plan node as intended (and as it seems to be,
in text format), it was actually an element of the "Plans" subgroup.
At least in JSON format, that's flat out invalid syntax, because
"Plans" is an array not an object.

While it's not hard to move the generation of the field so that it
appears where it's supposed to, this does result in a visible change
in field order in text format, in cases where a Append or MergeAppend
plan node has any InitPlans attached.  That's slightly annoying to
do in stable branches; but the alternative of continuing to emit
broken non-text formats seems worse.

Also, since the set of fields emitted is not supposed to be
data-dependent in non-text formats, make sure that "Subplans Removed"
appears in Append and MergeAppend nodes even when it's zero, in those
formats.  (The previous coding made it look like it could appear in
some other node types such as BitmapAnd, but we don't actually support
runtime pruning there, so don't emit it in those cases.)

Per bug #16171 from Mahadevan Ramachandran.  Fix by Daniel Gustafsson
and Tom Lane, reviewed by Hamid Akhtar.  Back-patch to v11 where this
code came in.

Discussion: https://postgr.es/m/16171-b72259ab75505fa2@postgresql.org
2020-02-04 13:07:13 -05:00
Alvaro Herrera c9d2977519 Clean up newlines following left parentheses
We used to strategically place newlines after some function call left
parentheses to make pgindent move the argument list a few chars to the
left, so that the whole line would fit under 80 chars.  However,
pgindent no longer does that, so the newlines just made the code
vertically longer for no reason.  Remove those newlines, and reflow some
of those lines for some extra naturality.

Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
2020-01-30 13:42:14 -03:00
Alvaro Herrera 4e89c79a52 Remove excess parens in ereport() calls
Cosmetic cleanup, not worth backpatching.

Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
Reviewed-by: Tom Lane, Michael Paquier
2020-01-30 13:32:04 -03:00
Fujii Masao e6f1e560e4 Make inherited TRUNCATE perform access permission checks on parent table only.
Previously, TRUNCATE command through a parent table checked the
permissions on not only the parent table but also the children tables
inherited from it. This was a bug and inherited queries should perform
access permission checks on the parent table only. This commit fixes
that bug.

Back-patch to all supported branches.

Author: Amit Langote
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAHGQGwFHdSvifhJE+-GSNqUHSfbiKxaeQQ7HGcYz6SC2n_oDcg@mail.gmail.com
2020-01-31 00:42:06 +09:00
Tom Lane 50fc694e43 Invent "trusted" extensions, and remove the pg_pltemplate catalog.
This patch creates a new extension property, "trusted".  An extension
that's marked that way in its control file can be installed by a
non-superuser who has the CREATE privilege on the current database,
even if the extension contains objects that normally would have to be
created by a superuser.  The objects within the extension will (by
default) be owned by the bootstrap superuser, but the extension itself
will be owned by the calling user.  This allows replicating the old
behavior around trusted procedural languages, without all the
special-case logic in CREATE LANGUAGE.  We have, however, chosen to
loosen the rules slightly: formerly, only a database owner could take
advantage of the special case that allowed installation of a trusted
language, but now anyone who has CREATE privilege can do so.

Having done that, we can delete the pg_pltemplate catalog, moving the
knowledge it contained into the extension script files for the various
PLs.  This ends up being no change at all for the in-core PLs, but it is
a large step forward for external PLs: they can now have the same ease
of installation as core PLs do.  The old "trusted PL" behavior was only
available to PLs that had entries in pg_pltemplate, but now any
extension can be marked trusted if appropriate.

This also removes one of the stumbling blocks for our Python 2 -> 3
migration, since the association of "plpythonu" with Python 2 is no
longer hard-wired into pg_pltemplate's initial contents.  Exactly where
we go from here on that front remains to be settled, but one problem
is fixed.

Patch by me, reviewed by Peter Eisentraut, Stephen Frost, and others.

Discussion: https://postgr.es/m/5889.1566415762@sss.pgh.pa.us
2020-01-29 18:42:43 -05:00
Amit Kapila 05f18c6b6b Added relation name in error messages for constraint checks.
This gives more information to the user about the error and it makes such
messages consistent with the other similar messages in the code.

Reported-by: Simon Riggs
Author: Mahendra Singh and Simon Riggs
Reviewed-by: Beena Emerson and Amit Kapila
Discussion: https://postgr.es/m/CANP8+j+7YUvQvGxTrCiw77R23enMJ7DFmyA3buR+fa2pKs4XhA@mail.gmail.com
2020-01-28 07:48:10 +05:30
Tom Lane 3ec20c7091 Fix EXPLAIN (SETTINGS) to follow policy about when to print empty fields.
In non-TEXT output formats, the "Settings" field should appear when
requested, even if it would be empty.

Also, get rid of the premature optimization of counting all the
GUC_EXPLAIN variables at startup.  Since there was no provision for
adjusting that count later, all it'd take would be some extension marking
a parameter as GUC_EXPLAIN to risk an assertion failure or memory stomp.
We could make get_explain_guc_options() count those variables on-the-fly,
or dynamically resize its array ... but TBH I do not think that making a
transient array of pointers a bit smaller is worth any extra complication,
especially when you consider all the other transient space EXPLAIN eats.
So just allocate that array at the max possible size.

In HEAD, also add some regression test coverage for this feature.

Because of the memory-stomp hazard, back-patch to v12 where this
feature was added.

Discussion: https://postgr.es/m/19416.1580069629@sss.pgh.pa.us
2020-01-26 16:32:19 -05:00
Tom Lane 1001368497 Clean up EXPLAIN's handling of per-worker details.
Previously, it was possible for EXPLAIN ANALYZE of a parallel query
to produce several different "Workers" fields for a single plan node,
because different portions of explain.c independently generated
per-worker data and wrapped that output in separate fields.  This
is pretty bogus, especially for the structured output formats: even
if it's not technically illegal, most programs would have a hard time
dealing with such data.

To improve matters, add infrastructure that allows redirecting
per-worker values into a side data structure, and then collect that
data into a single "Workers" field after we've finished running all
the relevant code for a given plan node.

There are a few visible side-effects:

* In text format, instead of something like

  Sort Method: external merge  Disk: 4920kB
  Worker 0:  Sort Method: external merge  Disk: 5880kB
  Worker 1:  Sort Method: external merge  Disk: 5920kB
  Buffers: shared hit=682 read=10188, temp read=1415 written=2101
  Worker 0:  actual time=130.058..130.324 rows=1324 loops=1
    Buffers: shared hit=337 read=3489, temp read=505 written=739
  Worker 1:  actual time=130.273..130.512 rows=1297 loops=1
    Buffers: shared hit=345 read=3507, temp read=505 written=744

you get

  Sort Method: external merge  Disk: 4920kB
  Buffers: shared hit=682 read=10188, temp read=1415 written=2101
  Worker 0:  actual time=130.058..130.324 rows=1324 loops=1
    Sort Method: external merge  Disk: 5880kB
    Buffers: shared hit=337 read=3489, temp read=505 written=739
  Worker 1:  actual time=130.273..130.512 rows=1297 loops=1
    Sort Method: external merge  Disk: 5920kB
    Buffers: shared hit=345 read=3507, temp read=505 written=744

* When JIT is enabled, any relevant per-worker JIT stats are attached
to the child node of the Gather or Gather Merge node, which is where
the other per-worker output has always been.  Previously, that info
was attached directly to a Gather node, or missed entirely for Gather
Merge.

* A query's summary JIT data no longer includes a bogus
"Worker Number: -1" field.

A notable code-level change is that indenting for lines of text-format
output should now be handled by calling "ExplainIndentText(es)",
instead of hard-wiring how much space to emit.  This seems a good deal
cleaner anyway.

This patch also adds a new "explain.sql" regression test script that's
dedicated to testing EXPLAIN.  There is more that can be done in that
line, certainly, but for now it just adds some coverage of the XML and
YAML output formats, which had been completely untested.

Although this is surely a bug fix, it's not clear that people would
be happy with rearranging EXPLAIN output in a minor release, so apply
to HEAD only.

Maciek Sakrejda and Tom Lane, based on an idea of Andres Freund's;
reviewed by Georgios Kokolatos

Discussion: https://postgr.es/m/CAOtHd0AvAA8CLB9Xz0wnxu1U=zJCKrr1r4QwwXi_kcQsHDVU=Q@mail.gmail.com
2020-01-25 18:16:42 -05:00
Michael Paquier a904abe2e2 Fix concurrent indexing operations with temporary tables
Attempting to use CREATE INDEX, DROP INDEX or REINDEX with CONCURRENTLY
on a temporary relation with ON COMMIT actions triggered unexpected
errors because those operations use multiple transactions internally to
complete their work.  Here is for example one confusing error when using
ON COMMIT DELETE ROWS:
ERROR:  index "foo" already contains data

Issues related to temporary relations and concurrent indexing are fixed
in this commit by enforcing the non-concurrent path to be taken for
temporary relations even if using CONCURRENTLY, transparently to the
user.  Using a non-concurrent path does not matter in practice as locks
cannot be taken on a temporary relation by a session different than the
one owning the relation, and the non-concurrent operation is more
effective.

The problem exists with REINDEX since v12 with the introduction of
CONCURRENTLY, and with CREATE/DROP INDEX since CONCURRENTLY exists for
those commands.  In all supported versions, this caused only confusing
error messages to be generated.  Note that with REINDEX, it was also
possible to issue a REINDEX CONCURRENTLY for a temporary relation owned
by a different session, leading to a server crash.

The idea to enforce transparently the non-concurrent code path for
temporary relations comes originally from Andres Freund.

Reported-by: Manuel Rigger
Author: Michael Paquier, Heikki Linnakangas
Reviewed-by: Andres Freund, Álvaro Herrera, Heikki Linnakangas
Discussion: https://postgr.es/m/CA+u7OA6gP7YAeCguyseusYcc=uR8+ypjCcgDDCTzjQ+k6S9ksQ@mail.gmail.com
Backpatch-through: 9.4
2020-01-22 09:49:18 +09:00
Tom Lane 9b9c5f279e Clarify behavior of adding and altering a column in same ALTER command.
The behavior of something like

ALTER TABLE transactions
  ADD COLUMN status varchar(30) DEFAULT 'old',
  ALTER COLUMN status SET default 'current';

is to fill existing table rows with 'old', not 'current'.  That's
intentional and desirable for a couple of reasons:

* It makes the behavior the same whether you merge the sub-commands
into one ALTER command or give them separately;

* If we applied the new default while filling the table, there would
be no way to get the existing behavior in one SQL command.

The same reasoning applies in cases that add a column and then
manipulate its GENERATED/IDENTITY status in a second sub-command,
since the generation expression is really just a kind of default.
However, that wasn't very obvious (at least not to me; earlier in
the referenced discussion thread I'd thought it was a bug to be
fixed).  And it certainly wasn't documented.

Hence, add documentation, code comments, and a test case to clarify
that this behavior is all intentional.

In passing, adjust ATExecAddColumn's defaults-related relkind check
so that it matches up exactly with ATRewriteTables, instead of being
effectively (though not literally) the negated inverse condition.
The reasoning can be explained a lot more concisely that way, too
(not to mention that the comment now matches the code, which it
did not before).

Discussion: https://postgr.es/m/10365.1558909428@sss.pgh.pa.us
2020-01-21 16:17:21 -05:00
Amit Kapila 40d964ec99 Allow vacuum command to process indexes in parallel.
This feature allows the vacuum to leverage multiple CPUs in order to
process indexes.  This enables us to perform index vacuuming and index
cleanup with background workers.  This adds a PARALLEL option to VACUUM
command where the user can specify the number of workers that can be used
to perform the command which is limited by the number of indexes on a
table.  Specifying zero as a number of workers will disable parallelism.
This option can't be used with the FULL option.

Each index is processed by at most one vacuum process.  Therefore parallel
vacuum can be used when the table has at least two indexes.

The parallel degree is either specified by the user or determined based on
the number of indexes that the table has, and further limited by
max_parallel_maintenance_workers.  The index can participate in parallel
vacuum iff it's size is greater than min_parallel_index_scan_size.

Author: Masahiko Sawada and Amit Kapila
Reviewed-by: Dilip Kumar, Amit Kapila, Robert Haas, Tomas Vondra,
Mahendra Singh and Sergei Kornilov
Tested-by: Mahendra Singh and Prabhat Sahu
Discussion:
https://postgr.es/m/CAD21AoDTPMgzSkV4E3SFo1CH_x50bf5PqZFQf4jmqjk-C03BWg@mail.gmail.com
https://postgr.es/m/CAA4eK1J-VoR9gzS5E75pcD-OH0mEyCdp8RihcwKrcuw7J-Q0+w@mail.gmail.com
2020-01-20 07:57:49 +05:30
Robert Haas 2eb34ac369 Fix problems with "read only query" checks, and refactor the code.
Previously, check_xact_readonly() was responsible for determining
which types of queries could not be run in a read-only transaction,
standard_ProcessUtility() was responsibility for prohibiting things
which were allowed in read only transactions but not in recovery, and
utility commands were basically prohibited in bulk in parallel mode by
calls to CommandIsReadOnly() in functions.c and spi.c.  This situation
was confusing and error-prone. Accordingly, move all the checks to a
new function ClassifyUtilityCommandAsReadOnly(), which determines the
degree to which a given statement is read only.

In the old code, check_xact_readonly() inadvertently failed to handle
several statement types that actually should have been prohibited,
specifically T_CreatePolicyStmt, T_AlterPolicyStmt, T_CreateAmStmt,
T_CreateStatsStmt, T_AlterStatsStmt, and T_AlterCollationStmt.  As a
result, thes statements were erroneously allowed in read only
transactions, parallel queries, and standby operation. Generally, they
would fail anyway due to some lower-level error check, but we
shouldn't rely on that.  In the new code structure, future omissions
of this type should cause ClassifyUtilityCommandAsReadOnly() to
complain about an unrecognized node type.

As a fringe benefit, this means we can allow certain types of utility
commands in parallel mode, where it's safe to do so. This allows
ALTER SYSTEM, CALL, DO, CHECKPOINT, COPY FROM, EXPLAIN, and SHOW.
It might be possible to allow additional commands with more work
and thought.

Along the way, document the thinking process behind the current set
of checks, as per discussion especially with Peter Eisentraut. There
is some interest in revising some of these rules, but that seems
like a job for another patch.

Patch by me, reviewed by Tom Lane, Stephen Frost, and Peter
Eisentraut.

Discussion: http://postgr.es/m/CA+TgmoZ_rLqJt5sYkvh+JpQnfX0Y+B2R+qfi820xNih6x-FQOQ@mail.gmail.com
2020-01-16 12:11:31 -05:00
Tom Lane 1281a5c907 Restructure ALTER TABLE execution to fix assorted bugs.
We've had numerous bug reports about how (1) IF NOT EXISTS clauses in
ALTER TABLE don't behave as-expected, and (2) combining certain actions
into one ALTER TABLE doesn't work, though executing the same actions as
separate statements does.  This patch cleans up all of the cases so far
reported from the field, though there are still some oddities associated
with identity columns.

The core problem behind all of these bugs is that we do parse analysis
of ALTER TABLE subcommands too soon, before starting execution of the
statement.  The root of the bugs in group (1) is that parse analysis
schedules derived commands (such as a CREATE SEQUENCE for a serial
column) before it's known whether the IF NOT EXISTS clause should cause
a subcommand to be skipped.  The root of the bugs in group (2) is that
earlier subcommands may change the catalog state that later subcommands
need to be parsed against.

Hence, postpone parse analysis of ALTER TABLE's subcommands, and do
that one subcommand at a time, during "phase 2" of ALTER TABLE which
is the phase that does catalog rewrites.  Thus the catalog effects
of earlier subcommands are already visible when we analyze later ones.
(The sole exception is that we do parse analysis for ALTER COLUMN TYPE
subcommands during phase 1, so that their USING expressions can be
parsed against the table's original state, which is what we need.
Arguably, these bugs stem from falsely concluding that because ALTER
COLUMN TYPE must do early parse analysis, every other command subtype
can too.)

This means that ALTER TABLE itself must deal with execution of any
non-ALTER-TABLE derived statements that are generated by parse analysis.
Add a suitable entry point to utility.c to accept those recursive
calls, and create a struct to pass through the information needed by
the recursive call, rather than making the argument lists of
AlterTable() and friends even longer.

Getting this to work correctly required a little bit of fiddling
with the subcommand pass structure, in particular breaking up
AT_PASS_ADD_CONSTR into multiple passes.  But otherwise it's mostly
a pretty straightforward application of the above ideas.

Fixing the residual issues for identity columns requires refactoring of
where the dependency link from an identity column to its sequence gets
set up.  So that seems like suitable material for a separate patch,
especially since this one is pretty big already.

Discussion: https://postgr.es/m/10365.1558909428@sss.pgh.pa.us
2020-01-15 18:49:24 -05:00
Alvaro Herrera a166d408eb Report progress of ANALYZE commands
This uses the progress reporting infrastructure added by c16dc1aca5,
adding support for ANALYZE.

Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Co-authored-by: Tatsuro Yamada <tatsuro.yamada.tf@nttcom.co.jp>
Reviewed-by: Julien Rouhaud, Robert Haas, Anthony Nowocien, Kyotaro Horiguchi,
	Vignesh C, Amit Langote
2020-01-15 11:14:39 -03:00
Peter Eisentraut f595117e24 ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
Add an ALTER TABLE subcommand for dropping the generated property from
a column, per SQL standard.

Reviewed-by: Sergei Kornilov <sk@zsrv.org>
Discussion: https://www.postgresql.org/message-id/flat/2f7f1d9c-946e-0453-d841-4f38eb9d69b6%402ndquadrant.com
2020-01-14 13:36:03 +01:00
Peter Eisentraut c67a55da4e Make lsn argument of walrcv_create_slot() optional
Some callers are not using it, so it's wasteful to have to specify it.

Reviewed-by: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/CA+fd4k4BcYrYucNfTnK-CQX3+jsG+PRPEhHAUSo-W4P0Lec57A@mail.gmail.com
2020-01-11 09:07:14 +01:00
Tom Lane 4ac8aaa36f Fix handling of generated columns in ALTER TABLE.
ALTER TABLE failed if a column referenced in a GENERATED expression
had been added or changed in type earlier in the ALTER command.
That's because the GENERATED expression needs to be evaluated
against the table's updated tuples, but it was being evaluated
against the original tuples.  (Fortunately the executor has adequate
cross-checks to notice the mismatch, so we just got an obscure error
message and not anything more dangerous.)

Per report from Andreas Joseph Krogh.  Back-patch to v12 where
GENERATED was added.

Discussion: https://postgr.es/m/VisenaEmail.200.231b0a41523275d0.16ea7f800c7@tc7-visena
2020-01-08 09:42:53 -05:00