Commit Graph

44279 Commits

Author SHA1 Message Date
Tom Lane a926eb84e0 Ensure that all temp files made during pg_upgrade are non-world-readable.
pg_upgrade has always attempted to ensure that the transient dump files
it creates are inaccessible except to the owner.  However, refactoring
in commit 76a7650c4 broke that for the file containing "pg_dumpall -g"
output; since then, that file was protected according to the process's
default umask.  Since that file may contain role passwords (hopefully
encrypted, but passwords nonetheless), this is a particularly unfortunate
oversight.  Prudent users of pg_upgrade on multiuser systems would
probably run it under a umask tight enough that the issue is moot, but
perhaps some users are depending only on pg_upgrade's umask changes to
protect their data.

To fix this in a future-proof way, let's just tighten the umask at
process start.  There are no files pg_upgrade needs to write at a
weaker security level; and if there were, transiently relaxing the
umask around where they're created would be a safer approach.

Report and patch by Tom Lane; the idea for the fix is due to Noah Misch.
Back-patch to all supported branches.

Security: CVE-2018-1053
2018-02-05 10:58:27 -05:00
Tom Lane 3492a0af0b Fix RelationBuildPartitionKey's processing of partition key expressions.
Failure to advance the list pointer while reading partition expressions
from a list results in invoking an input function with inappropriate data,
possibly leading to crashes or, with carefully crafted input, disclosure
of arbitrary backend memory.

Bug discovered independently by Álvaro Herrera and David Rowley.
This patch is by Álvaro but owes something to David's proposed fix.
Back-patch to v10 where the issue was introduced.

Security: CVE-2018-1052
2018-02-05 10:37:30 -05:00
Tom Lane 05d0f13f07 Skip setting up shared instrumentation for Hash node if not needed.
We don't need to set up the shared space for hash join instrumentation data
if instrumentation hasn't been requested.  Let's follow the example of the
similar Sort node code and save a few cycles by skipping that when we can.

This reverts commit d59ff4ab3 and instead allows us to use the safer choice
of passing noError = false to shm_toc_lookup in ExecHashInitializeWorker,
since if we reach that call there should be a TOC entry to be found.

Thomas Munro

Discussion: https://postgr.es/m/E1ehkoZ-0005uW-43%40gemulon.postgresql.org
2018-02-04 22:14:07 -05:00
Peter Eisentraut ad14919ac9 doc: Update mentions of MD5 in the documentation
Reported-by: Shay Rojansky <roji@roji.org>
2018-02-04 16:38:08 -05:00
Tom Lane cf1cba3110 Release notes for 10.2, 9.6.7, 9.5.11, 9.4.16, 9.3.21. 2018-02-04 15:13:44 -05:00
Tom Lane 64fb645914 Doc: minor clarifications in xindex.sgml.
I noticed some slightly confusing or out-of-date verbiage here
while working on the window RANGE patch.  Seems worth committing
separately.
2018-02-04 11:46:28 -05:00
Peter Eisentraut 4ac583f36a doc: Fix name in release notes
Author: Alexander Lakhin <exclusion@gmail.com>
2018-02-03 11:09:24 -05:00
Peter Eisentraut 1d81c093db doc: Clarify psql --list documentation a bit more 2018-02-03 10:19:57 -05:00
Tom Lane 794eb3a8f0 Minor copy-editing for 10.2 release notes.
Second pass after taking a break ...
2018-02-02 22:33:47 -05:00
Peter Eisentraut bc38bdba04 doc: Fix index link
The index entry was pointing to a slightly wrong location.
2018-02-02 21:10:59 -05:00
Tom Lane d59ff4ab31 Fix another instance of unsafe coding for shm_toc_lookup failure.
One or another author of commit 5bcf389ec seems to have thought that
computing an offset from a NULL pointer would yield another NULL pointer.
There may possibly be architectures where that works, but common machines
don't work like that.  Per a quick code review of places calling
shm_toc_lookup and not using noError = false.
2018-02-02 18:32:05 -05:00
Tom Lane 957ff087c8 Be more wary about shm_toc_lookup failure.
Commit 445dbd82a basically missed the point of commit d46633506,
which was that we shouldn't allow shm_toc_lookup() failure to lead
to a core dump or assertion crash, because the odds of such a
failure should never be considered negligible.  It's correct that
we can't expect the PARALLEL_KEY_ERROR_QUEUE TOC entry to be there
if we have no workers.  But if we have no workers, we're not going
to do anything in this function with the lookup result anyway,
so let's just skip it.  That lets the code use the easy-to-prove-safe
noError=false case, rather than anything requiring effort to review.

Back-patch to v10, like the previous commit.

Discussion: https://postgr.es/m/3647.1517601675@sss.pgh.pa.us
2018-02-02 18:26:07 -05:00
Tom Lane bf641d3376 First-draft release notes for 10.2.
As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first.
2018-02-02 17:10:46 -05:00
Peter Eisentraut 533c5d8bdd Fix application of identity values in some cases
Investigation of 2d2d06b7e2 revealed that
identity values were not applied in some further cases, including
logical replication subscribers, VALUES RTEs, and ALTER TABLE ... ADD
COLUMN.  To fix all that, apply the identity column expression in
build_column_default() instead of repeating the same logic at each call
site.

For ALTER TABLE ... ADD COLUMN ... IDENTITY, the previous coding
completely ignored that existing rows for the new column should have
values filled in from the identity sequence.  The coding using
build_column_default() fails for this because the sequence ownership
isn't registered until after ALTER TABLE, and we can't do it before
because we don't have the column in the catalog yet.  So we specially
remember in ColumnDef the sequence name that we decided on and build a
custom NextValueExpr using that.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2018-02-02 14:39:10 -05:00
Robert Haas 9da0cc3528 Support parallel btree index builds.
To make this work, tuplesort.c and logtape.c must also support
parallelism, so this patch adds that infrastructure and then applies
it to the particular case of parallel btree index builds.  Testing
to date shows that this can often be 2-3x faster than a serial
index build.

The model for deciding how many workers to use is fairly primitive
at present, but it's better than not having the feature.  We can
refine it as we get more experience.

Peter Geoghegan with some help from Rushabh Lathia.  While Heikki
Linnakangas is not an author of this patch, he wrote other patches
without which this feature would not have been possible, and
therefore the release notes should possibly credit him as an author
of this feature.  Reviewed by Claudio Freire, Heikki Linnakangas,
Thomas Munro, Tels, Amit Kapila, me.

Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com
Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com
2018-02-02 13:32:44 -05:00
Robert Haas 9aef173163 Refactor code for partition bound searching
Remove partition_bound_cmp() and partition_bound_bsearch(), whose
void * argument could be, depending on the situation, of any of
three different types: PartitionBoundSpec *, PartitionRangeBound *,
Datum *.

Instead, introduce separate bound-searching functions for each
situation: partition_list_bsearch, partition_range_bsearch,
partition_range_datum_bsearch, and partition_hash_bsearch.  This
requires duplicating the code for binary search, but it makes the
code much more type safe, involves fewer branches at runtime, and
at least in my opinion, is much easier to understand.

Along the way, add an option to partition_range_datum_bsearch
allowing the number of keys to be specified, so that we can search
for partitions based on a prefix of the full list of partition
keys.  This is important for pending work to improve partition
pruning.

Amit Langote, per a suggestion from me.

Discussion: http://postgr.es/m/CA+TgmoaVLDLc8=YESRwD32gPhodU_ELmXyKs77gveiYp+JE4vQ@mail.gmail.com
2018-02-02 09:32:44 -05:00
Robert Haas 9222c0d9ed Add new function WaitForParallelWorkersToAttach.
Once this function has been called, we know that all workers have
started and attached to their error queues -- so if any of them
subsequently exit uncleanly, we'll be sure to throw an ERROR promptly.
Otherwise, users of the ParallelContext machinery must be careful not
to wait forever for a worker that has failed to start.  Parallel query
manages to work without needing this for reasons explained in new
comments added by this patch, but it's a useful primitive for other
parallel operations, such as the pending patch to make creating a
btree index run in parallel.

Amit Kapila, revised by me.  Additional review by Peter Geoghegan.

Discussion: http://postgr.es/m/CAA4eK1+e2MzyouF5bg=OtyhDSX+=Ao=3htN=T-r_6s3gCtKFiw@mail.gmail.com
2018-02-02 09:00:59 -05:00
Stephen Frost a2a2205761 Improve ALTER TABLE synopsis
Add into the ALTER TABLE synopsis the definition of
partition_bound_spec, column_constraint, index_parameters and
exclude_element.

Initial patch by Lætitia Avrot, with further improvements by Amit
Langote and Thomas Munro.

Discussion: https://postgr.es/m/flat/27ec4df3-d1ab-3411-f87f-647f944897e1%40lab.ntt.co.jp
2018-02-02 05:30:04 -05:00
Robert Haas ad25a6b1f2 Fix possible failure to mark hash metapage dirty.
Report and suggested fix by Lixian Zou.  Amit Kapila put it
in the form of a patch and reviewed.

Discussion: http://postgr.es/m/151739848647.1239.12528851873396651946@wrigleys.postgresql.org
2018-02-01 15:23:45 -05:00
Bruce Momjian df9f599bc6 psql: Add quit/help behavior/hint, for other tool portability
Issuing 'quit'/'exit' in an empty psql buffer exits psql.  Issuing
'quit'/'exit' in a non-empty psql buffer alone on a line with no prefix
whitespace issues a hint on how to exit.

Also add similar 'help' hints for 'help' in a non-empty psql buffer.

Reported-by: Everaldo Canuto

Discussion: https://postgr.es/m/flat/CALVFHFb-C_5_94hueWg6Dd0zu7TfbpT7hzsh9Zf0DEDOSaAnfA%40mail.gmail.com

Author: original author Robert Haas, modified by me
2018-02-01 08:30:43 -05:00
Bruce Momjian eab30cc6b5 doc: fix trigger inheritance wording
Fix wording from commit 1cf1112990

Reported-by: Robert Haas

Backpatch-through: 10
2018-01-31 17:52:47 -05:00
Bruce Momjian 59ad246350 doc: clarify major/minor pg_upgrade versions with examples
The previous docs added in PG 10 were not clear enough for someone who
didn't understand the PG 10 version change, so give more specific
examples.

Reported-by: jim@room118solutions.com

Discussion: https://postgr.es/m/20171218213041.25744.8414@wrigleys.postgresql.org

Backpatch-through: 10
2018-01-31 17:09:59 -05:00
Bruce Momjian 1cf1112990 doc: clearify trigger behavior for inheritance
The previous wording added in PG 10 wasn't specific enough about the
behavior of statement and row triggers when using inheritance.

Reported-by: ian@thepathcentral.com

Discussion: https://postgr.es/m/20171129193934.27108.30796@wrigleys.postgresql.org

Backpatch-through: 10
2018-01-31 17:00:17 -05:00
Bruce Momjian 3b15255912 doc: in contrib-spi, mention and link to the meaning of SPI
Also remove outdated comment about SPI subtransactions.

Reported-by: gregory@arenius.com

Discussion: https://postgr.es/m/151726276676.1240.10501743959198501067@wrigleys.postgresql.org

Backpatch-through: 9.3
2018-01-31 16:54:33 -05:00
Robert Haas 22757960bb Fix typo: colums -> columns.
Along the way, also fix code indentation.

Alexander Lakhin, reviewed by Michael Paquier

Discussion: http://postgr.es/m/45c44aa7-7cfa-7f3b-83fd-d8300677fdda@gmail.com
2018-01-31 16:45:37 -05:00
Bruce Momjian de71541460 doc: Improve pg_upgrade rsync examples to use clusterdir
Commit 9521ce4a7a from Sep 13, 2017 and
backpatched through 9.5 used rsync examples with datadir.  The reporter
has pointed out, and testing has verified, that clusterdir must be used,
so update the docs accordingly.

Reported-by: Don Seiler

Discussion: https://postgr.es/m/CAHJZqBD0u9dCERpYzK6BkRv=663AmH==DFJpVC=M4Xg_rq2=CQ@mail.gmail.com

Backpatch-through: 9.5
2018-01-31 16:43:40 -05:00
Robert Haas d40d97d6c7 pgcrypto's encrypt() supports AES-128, AES-192, and AES-256
Previously, only 128 was mentioned, but the others are also supported.

Thomas Munro, reviewed by Michael Paquier and extended a bit by me.

Discussion: http://postgr.es/m/CAEepm=1XbBHXYJKofGjnM2Qfz-ZBVqhGU4AqvtgR+Hegy4fdKg@mail.gmail.com
2018-01-31 16:33:11 -05:00
Bruce Momjian e5dede9097 doc: mention datadir locations are actually config locations
Technically, pg_upgrade's --old-datadir and --new-datadir are
configuration directories, not necessarily data directories.  This is
reflected in the 'postgres' manual page, so do the same for pg_upgrade.

Reported-by: Yves Goergen

Bug: 14898

Discussion: https://postgr.es/m/20171110220912.31513.13322@wrigleys.postgresql.org

Backpatch-through: 10
2018-01-31 16:25:21 -05:00
Robert Haas 3ccdc6f9a5 Fix list partition constraints for partition keys of array type.
The old code generated always generated a constraint of the form
col = ANY(ARRAY[val1, val2, ...]), but that's invalid when col is an
array type.  Instead, generate col = val when there's only one value,
col = val1 OR col = val2 OR ... when there are multiple values and
col is of array type, and the old form when there are multiple values
and col is not of an array type.

As a side benefit, this makes constraint exclusion able to prune
a list partition declared to accept a single Boolean value, which
didn't work before.

Amit Langote, reviewed by Etsuro Fujita

Discussion: http://postgr.es/m/97267195-e235-89d1-a41a-c110198dfce9@lab.ntt.co.jp
2018-01-31 15:43:11 -05:00
Robert Haas 0ff5bd7b47 pg_prewarm: Add missing LWLockRegisterTranche call.
Commit 79ccd7cbd5, which added automatic
prewarming, neglected this.

Kyotaro Horiguchi, reviewed by me.

Discussion: http://postgr.es/m/20171215.173219.38055760.horiguchi.kyotaro@lab.ntt.co.jp
2018-01-31 15:12:33 -05:00
Peter Eisentraut f75a959155 Refactor client-side SSL certificate checking code
Separate the parts specific to the SSL library from the general logic.

The previous code structure was

open_client_SSL()
calls verify_peer_name_matches_certificate()
calls verify_peer_name_matches_certificate_name()
calls wildcard_certificate_match()

and was completely in fe-secure-openssl.c.  The new structure is

open_client_SSL() [openssl]
calls pq_verify_peer_name_matches_certificate() [generic]
calls pgtls_verify_peer_name_matches_certificate_guts() [openssl]
calls openssl_verify_peer_name_matches_certificate_name() [openssl]
calls pq_verify_peer_name_matches_certificate_name() [generic]
calls wildcard_certificate_match() [generic]

Move the generic functions into a new file fe-secure-common.c, so the
calls generally go fe-connect.c -> fe-secure.c -> fe-secure-${impl}.c ->
fe-secure-common.c, although there is a bit of back-and-forth between
the last two.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2018-01-30 22:56:24 -05:00
Peter Eisentraut 38d485fdaa Fix up references to scram-sha-256
pg_hba_file_rules erroneously reported this as scram-sha256.  Fix that.

To avoid future errors and confusion, also adjust documentation links
and internal symbols to have a separator between "sha" and "256".

Reported-by: Christophe Courtois <christophe.courtois@dalibo.com>
Author: Michael Paquier <michael.paquier@gmail.com>
2018-01-30 16:50:30 -05:00
Robert Haas 99f6a17dd6 Fix test case for 'outer pathkeys do not match mergeclauses' fix.
Commit 4bbf6edfbd added a test case,
but it turns out that the test case doesn't reliably test for the
bug, and in the context of the regression test suite did not because
ANALYZE had not been run.

Report and patch by Etsuro Fujita.  I added a comment along lines
previously suggested by Tom Lane.

Discussion: http://postgr.es/m/5A6195D8.8060206@lab.ntt.co.jp
2018-01-30 14:44:30 -05:00
Peter Eisentraut a044378ce2 Add some noreturn attributes to help static analyzers 2018-01-29 20:44:35 -05:00
Peter Eisentraut 07e524d3e9 Silence complaint about dead assignment
The preferred place for "placate compiler" assignments is after
elog(ERROR), not before it.  Otherwise, scan-build complains about a
dead assignment.
2018-01-29 20:43:43 -05:00
Peter Eisentraut 6ad3611e1e Remove dead assignment
per scan-build
2018-01-29 20:41:36 -05:00
Andres Freund c12693d8f3 Introduce ExecQualAndReset() helper.
It's a common task to evaluate a qual and reset the corresponding
expression context. Currently that requires storing the result of the
qual eval, resetting the context, and then reacting on the result. As
that's awkward several places only reset the context next time through
a node. That's not great, so introduce a helper that evaluates and
resets.

It's a bit ugly that it currently uses MemoryContextReset() instead of
ResetExprContext(), but that seems easier than reordering all of
executor.h.

Author: Andres Freund
Discussion: https://postgr.es/m/20180109222544.f7loxrunqh3xjl5f@alap3.anarazel.de
2018-01-29 12:19:12 -08:00
Tom Lane 97d4445a03 Save a few bytes by removing useless last argument to SearchCatCacheList.
There's never any value in giving a fully specified cache key to
SearchCatCacheList: you might as well call SearchCatCache instead,
since there could be only one match.  So the maximum useful number of
key arguments is one less than the supported number of key columns.
We might as well remove the useless extra argument and save some few
bytes per call site, as well as a cycle or so per call.

I believe the reason it was coded like this is that originally, callers
had to write out all the dummy arguments in each call, and so it seemed
less confusing if SearchCatCache and SearchCatCacheList took the same
number of key arguments.  But since commit e26c539e9, callers only write
their live arguments explicitly, making that a non-factor; and there's
surely been enough time for third-party modules to adapt to that coding
style.  So this is only an ABI break not an API break for callers.

Per discussion with Oliver Ford, this might also make it less confusing
how to use SearchCatCacheList correctly.

Discussion: https://postgr.es/m/27788.1517069693@sss.pgh.pa.us
2018-01-29 15:13:17 -05:00
Andres Freund fc96c69425 Initialize unused ExprEvalStep fields.
ExecPushExprSlots didn't initialize ExprEvalStep's resvalue/resnull
steps as it didn't use them. That caused wrong valgrind warnings for
an upcoming patch, so zero-intialize.

Also zero-initialize all scratch ExprEvalStep's allocated on the
stack, to avoid issues with similar future omissions of non-critial
data.
2018-01-29 12:01:07 -08:00
Peter Eisentraut 1e1e599d66 doc: Clarify pg_upgrade documentation
Clarify that the restriction against reg* types only applies to table
columns using these types, not to the type appearing in any other way,
for example as a function argument.
2018-01-29 14:26:17 -05:00
Andres Freund ab9f2c429d Prevent growth of simplehash tables when they're "too empty".
In cases where simplehash tables where filled with either a lot of
conflicting hash-values, or values that hash to consecutive
values (i.e. build "chains") the growth heuristics in
d4c62a6b62 could trigger rather
explosively.

To fix that, address some of the reasons (see previous commit) of why
the growth heuristics where needed, and only allow growth when the
table isn't too empty. While that means there's a few cases of bad
input that can be slower, that seems a lot better than running very
quickly out of memory.

Author: Tomas Vondra and Andres Freund, with additional input by
    Thomas Munro, Tom Lane Todd A. Cook
Reported-By: Todd A. Cook, Tomas Vondra, Thomas Munro
Discussion: https://postgr.es/m/20171127185700.1470.20362@wrigleys.postgresql.org
Backpatch: 10, where simplehash was introduced
2018-01-29 11:24:57 -08:00
Andres Freund c068f87723 Improve bit perturbation in TupleHashTableHash.
The changes in b81b5a96f4 did not fully
address the issue, because the bit-mixing of the IV into the final
hash-key didn't prevent clustering in the input-data survive in the
output data.

This didn't cause a lot of problems because of the additional growth
conditions added d4c62a6b62. But as we
want to rein those in due to explosive growth in some edges, this
needs to be fixed.

Author: Andres Freund
Discussion: https://postgr.es/m/20171127185700.1470.20362@wrigleys.postgresql.org
Backpatch: 10, where simplehash was introduced
2018-01-29 11:24:57 -08:00
Tom Lane 15be274601 Avoid misleading psql password prompt when username is multiply specified.
When a password is needed, cases such as
	psql -d "postgresql://alice@localhost/testdb" -U bob
would incorrectly prompt for "Password for user bob: ", when actually the
connection will be attempted with username alice.  The priority order of
which name to use isn't that important here, but the misleading prompt is.

When we are prompting for a password after initial connection failure,
we can fix this reliably by looking at PQuser(conn) to see how libpq
interpreted the connection arguments.  But when we're doing a forced
password prompt because of a -W switch, we can't use that solution.
Fortunately, because the main use of -W is for noninteractive situations,
it's less critical to produce a helpful prompt in such cases.  I made
the startup prompt for -W just say "Password: " all the time, rather
than expending extra code on trying to identify which username to use.
In the case of a \c command (after -W has been given), there's already
logic in do_connect that determines whether the "dbname" is a connstring
or URI, so we can avoid lobotomizing the prompt except in cases that
are actually dubious.  (We could do similarly in startup.c if anyone
complains, but for now it seems not worthwhile, especially since that
would still be only a partial solution.)

Per bug #15025 from Akos Vandra.  Although this is arguably a bug fix,
it doesn't seem worth back-patching.  The case where it matters seems
like a very corner-case usage, and someone might complain that we'd
changed the behavior of -W in a minor release.

Discussion: https://postgr.es/m/20180123130013.7407.24749@wrigleys.postgresql.org
2018-01-29 12:57:09 -05:00
Tom Lane 35a528062c Add stack-overflow guards in set-operation planning.
create_plan_recurse lacked any stack depth check.  This is not per
our normal coding rules, but I'd supposed it was safe because earlier
planner processing is more complex and presumably should eat more
stack.  But bug #15033 from Andrew Grossman shows this isn't true,
at least not for queries having the form of a many-thousand-way
INTERSECT stack.

Further testing showed that recurse_set_operations is also capable
of being crashed in this way, since it likewise will recurse to the
bottom of a parsetree before calling any support functions that
might themselves contain any stack checks.  However, its stack
consumption is only perhaps a third of create_plan_recurse's.

It's possible that this particular problem with create_plan_recurse can
only manifest in 9.6 and later, since before that we didn't build a Path
tree for set operations.  But having seen this example, I now have no
faith in the proposition that create_plan_recurse doesn't need a stack
check, so back-patch to all supported branches.

Discussion: https://postgr.es/m/20180127050845.28812.58244@wrigleys.postgresql.org
2018-01-28 13:39:07 -05:00
Bruce Momjian 010123e144 C includes: Reorder C includes in partition.c
Discussion: https://postgr.es/m/5A69AA50.2060600@lab.ntt.co.jp

Author: Etsuro Fujita
2018-01-27 23:05:52 -05:00
Tom Lane 41fc04ff91 Update time zone data files to tzdata release 2018c.
DST law changes in Brazil, Sao Tome and Principe.  Historical corrections
for Bolivia, Japan, and South Sudan.  The "US/Pacific-New" zone has been
removed (it was only a link to America/Los_Angeles anyway).
2018-01-27 16:42:28 -05:00
Tom Lane 2e668c522e Avoid crash during EvalPlanQual recheck of an inner indexscan.
Commit 09529a70b changed nodeIndexscan.c and nodeIndexonlyscan.c to
postpone initialization of the indexscan proper until the first tuple
fetch.  It overlooked the question of mark/restore behavior, which means
that if some caller attempts to mark the scan before the first tuple fetch,
you get a null pointer dereference.

The only existing user of mark/restore is nodeMergejoin.c, which (somewhat
accidentally) will never attempt to set a mark before the first inner tuple
unless the inner child node is a Material node.  Hence the case can't arise
normally, so it seems sufficient to document the assumption at both ends.
However, during an EvalPlanQual recheck, ExecScanFetch doesn't call
IndexNext but just returns the jammed-in test tuple.  Therefore, if we're
doing a recheck in a plan tree with a mergejoin with inner indexscan,
it's possible to reach ExecIndexMarkPos with iss_ScanDesc still null,
as reported by Guo Xiang Tan in bug #15032.

Really, when there's a test tuple supplied during an EPQ recheck, touching
the index at all is the wrong thing: rather, the behavior of mark/restore
ought to amount to saving and restoring the es_epqScanDone flag.  We can
avoid finding a place to actually save the flag, for the moment, because
given the assumption that no caller will set a mark before fetching a
tuple, es_epqScanDone must always be set by the time we try to mark.
So the actual behavior change required is just to not reach the index
access if a test tuple is supplied.

The set of plan node types that need to consider this issue are those
that support EPQ test tuples (i.e., call ExecScan()) and also support
mark/restore; which is to say, IndexScan, IndexOnlyScan, and perhaps
CustomScan.  It's tempting to try to fix the problem in one place by
teaching ExecMarkPos() itself about EPQ; but ExecMarkPos supports some
plan types that aren't Scans, and also it seems risky to make assumptions
about what a CustomScan wants to do here.  Also, the most likely future
change here is to decide that we do need to support marks placed before
the first tuple, which would require additional work in IndexScan and
IndexOnlyScan in any case.  Hence, fix the EPQ issue in nodeIndexscan.c
and nodeIndexonlyscan.c, accepting the small amount of code duplicated
thereby, and leave it to CustomScan providers to fix this bug if they
have it.

Back-patch to v10 where commit 09529a70b came in.  In earlier branches,
the index_markpos() call is a waste of cycles when EPQ is active, but
no more than that, so it doesn't seem appropriate to back-patch further.

Discussion: https://postgr.es/m/20180126074932.3098.97815@wrigleys.postgresql.org
2018-01-27 13:52:24 -05:00
Magnus Hagander ba8c2dfffd Add missing semicolons in documentation examples
Author: Daniel Gustafsson <daniel@yesql.se>
2018-01-27 13:13:52 +01:00
Tom Lane fb8697b31a Avoid unnecessary use of pg_strcasecmp for already-downcased identifiers.
We have a lot of code in which option names, which from the user's
viewpoint are logically keywords, are passed through the grammar as plain
identifiers, and then matched to string literals during command execution.
This approach avoids making words into lexer keywords unnecessarily.  Some
places matched these strings using plain strcmp, some using pg_strcasecmp.
But the latter should be unnecessary since identifiers would have been
downcased on their way through the parser.  Aside from any efficiency
concerns (probably not a big factor), the lack of consistency in this area
creates a hazard of subtle bugs due to different places coming to different
conclusions about whether two option names are the same or different.
Hence, standardize on using strcmp() to match any option names that are
expected to have been fed through the parser.

This does create a user-visible behavioral change, which is that while
formerly all of these would work:
	alter table foo set (fillfactor = 50);
	alter table foo set (FillFactor = 50);
	alter table foo set ("fillfactor" = 50);
	alter table foo set ("FillFactor" = 50);
now the last case will fail because that double-quoted identifier is
different from the others.  However, none of our documentation says that
you can use a quoted identifier in such contexts at all, and we should
discourage doing so since it would break if we ever decide to parse such
constructs as true lexer keywords rather than poor man's substitutes.
So this shouldn't create a significant compatibility issue for users.

Daniel Gustafsson, reviewed by Michael Paquier, small changes by me

Discussion: https://postgr.es/m/29405B24-564E-476B-98C0-677A29805B84@yesql.se
2018-01-26 18:25:14 -05:00
Robert Haas 9fd8b7d632 Factor some code out of create_grouping_paths.
This is preparatory refactoring to prepare the way for partition-wise
aggregate, which will reuse the new subroutines for child grouping
rels.  It also does not seem like a bad idea on general principle,
as the function was getting pretty long.

Jeevan Chalke.  The larger patch series of which this patch is a part
was reviewed and tested by Antonin Houska, Rajkumar Raghuwanshi,
Ashutosh Bapat, David Rowley, Dilip Kumar, Konstantin Knizhnik,
Pascal Legrand, and me.  Some cosmetic changes by me.

Discussion: http://postgr.es/m/CAM2+6=V64_xhstVHie0Rz=KPEQnLJMZt_e314P0jaT_oJ9MR8A@mail.gmail.com
2018-01-26 15:03:12 -05:00