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39841 Commits

Author SHA1 Message Date
53afdef662 Improve RLS documentation with respect to COPY
Documentation for pg_restore said COPY TO does not support row security
when in fact it should say COPY FROM. Fix that.

While at it, make it clear that "COPY FROM" does not allow RLS to be
enabled and INSERT should be used instead. Also that SELECT policies
will apply to COPY TO statements.

Back-patch to 9.5 where RLS first appeared.

Author: Joe Conway
Reviewed-By: Dean Rasheed and Robert Haas
Discussion: https://postgr.es/m/5744FA24.3030008%40joeconway.com
2016-12-22 17:57:14 -08:00
e823692177 Use TSConfigRelationId in AlterTSConfiguration()
When we are altering a text search configuration, we are getting the
tuple from pg_ts_config and using its OID, so use TSConfigRelationId
when invoking any post-alter hooks and setting the object address.

Further, in the functions called from AlterTSConfiguration(), we're
saving information about the command via
EventTriggerCollectAlterTSConfig(), so we should be setting
commandCollected to true.  Also add a regression test to
test_ddl_deparse for ALTER TEXT SEARCH CONFIGURATION.

Author: Artur Zakirov, a few additional comments by me
Discussion: https://www.postgresql.org/message-id/57a71eba-f2c7-e7fd-6fc0-2126ec0b39bd%40postgrespro.ru

Back-patch the fix for the InvokeObjectPostAlterHook() call to 9.3 where
it was introduced, and the fix for the ObjectAddressSet() call and
setting commandCollected to true to 9.5 where those changes to
ProcessUtilitySlow() were introduced.
2016-12-22 17:08:49 -05:00
c472f2a335 Fix handling of expanded objects in CoerceToDomain and CASE execution.
When the input value to a CoerceToDomain expression node is a read-write
expanded datum, we should pass a read-only pointer to any domain CHECK
expressions and then return the original read-write pointer as the
expression result.  Previously we were blindly passing the same pointer to
all the consumers of the value, making it possible for a function in CHECK
to modify or even delete the expanded value.  (Since a plpgsql function
will absorb a passed-in read-write expanded array as a local variable
value, it will in fact delete the value on exit.)

A similar hazard of passing the same read-write pointer to multiple
consumers exists in domain_check() and in ExecEvalCase, so fix those too.

The fix requires adding MakeExpandedObjectReadOnly calls at the appropriate
places, which is simple enough except that we need to get the data type's
typlen from somewhere.  For the domain cases, solve this by redefining
DomainConstraintRef.tcache as okay for callers to access; there wasn't any
reason for the original convention against that, other than not wanting the
API of typcache.c to be any wider than it had to be.  For CASE, there's
no good solution except to add a syscache lookup during executor start.

Per bug #14472 from Marcos Castedo.  Back-patch to 9.5 where expanded
values were introduced.

Discussion: https://postgr.es/m/15225.1482431619@sss.pgh.pa.us
2016-12-22 15:01:39 -05:00
aa04e5c3c1 Fix broken error check in _hash_doinsert.
You can't just cast a HashMetaPage to a Page, because the meta page
data is stored after the page header, not at offset 0.  Fortunately,
this didn't break anything because it happens to find hashm_bsize
at the offset at which it expects to find pd_pagesize_version, and
the values are close enough to the same that this works out.

Still, it's a bug, so back-patch to all supported versions.

Mithun Cy, revised a bit by me.
2016-12-22 14:03:07 -05:00
80ca22aa60 Make dblink try harder to form useful error messages
When libpq encounters a connection-level error, e.g. runs out of memory
while forming a result, there will be no error associated with PGresult,
but a message will be placed into PGconn's error buffer. postgres_fdw
takes care to use the PGconn error message when PGresult does not have
one, but dblink has been negligent in that regard. Modify dblink to mirror
what postgres_fdw has been doing.

Back-patch to all supported branches.

Author: Joe Conway
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/02fa2d90-2efd-00bc-fefc-c23c00eb671e%40joeconway.com
2016-12-22 09:47:46 -08:00
d5c05f27a4 Protect dblink from invalid options when using postgres_fdw server
When dblink uses a postgres_fdw server name for its connection, it
is possible for the connection to have options that are invalid
with dblink (e.g. "updatable"). The recommended way to avoid this
problem is to use dblink_fdw servers instead. However there are use
cases for using postgres_fdw, and possibly other FDWs, for dblink
connection options, therefore protect against trying to use any
options that do not apply by using is_valid_dblink_option() when
building the connection string from the options.

Back-patch to 9.3. Although 9.2 supports FDWs for connection info,
is_valid_dblink_option() did not yet exist, and neither did
postgres_fdw, at least in the postgres source tree. Given the lack
of previous complaints, fixing that seems too invasive/not worth it.

Author: Corey Huinker
Reviewed-By: Joe Conway
Discussion: https://postgr.es/m/CADkLM%3DfWyXVEyYcqbcRnxcHutkP45UHU9WD7XpdZaMfe7S%3DRwA%40mail.gmail.com
2016-12-22 09:19:18 -08:00
1cfdb29c7d Give a useful error message if uuid-ossp is built without preconfiguration.
Before commit b8cc8f947, it was possible to build contrib/uuid-ossp without
having told configure you meant to; you could just cd into that directory
and "make".  That no longer works because the code depends on configure to
have done header and library probes, but the ensuing error messages are
not so easy to interpret if you're not an old C hand.  We've gotten a
couple of complaints recently from people trying to do this the low-tech
way, so add an explicit #error directing the user to use --with-uuid.

(In principle we might want to do something similar in the other
optionally-built contrib modules; but I don't think any of the others have
ever worked without preconfiguration, so there are no bad habits to break
people of.)

Back-patch to 9.4 where the previous commit came in.

Report: https://postgr.es/m/CAHeEsBf42AWTnk=1qJvFv+mYgRFm07Knsfuc86Ono8nRjf3tvQ@mail.gmail.com
Report: https://postgr.es/m/CAKYdkBrUaZX+F6KpmzoHqMtiUqCtAW_w6Dgvr6F0WTiopuGxow@mail.gmail.com
2016-12-22 11:19:18 -05:00
a88c547f92 Fix buffer overflow on particularly named files and clarify documentation about
output file naming.

Patch by Tsunakawa, Takayuki <tsunakawa.takay@jp.fujitsu.com>
2016-12-22 08:29:33 +01:00
28c9b6be7f Improve dblink error message when remote does not provide it
When dblink or postgres_fdw detects an error on the remote side of the
connection, it will try to construct a local error message as best it
can using libpq's PQresultErrorField(). When no primary message is
available, it was bailing out with an unhelpful "unknown error". Make
that message better and more style guide compliant. Per discussion
on hackers.

Backpatch to 9.2 except postgres_fdw which didn't exist before 9.3.

Discussion: https://postgr.es/m/19872.1482338965%40sss.pgh.pa.us
2016-12-21 15:51:57 -08:00
d5633af7b6 Fix detection of unfinished Unicode surrogate pair at end of string.
The U&'...' and U&"..." syntaxes silently discarded a surrogate pair
start (that is, a code between U+D800 and U+DBFF) if it occurred at
the very end of the string.  This seems like an obvious oversight,
since we throw an error for every other invalid combination of surrogate
characters, including the very same situation in E'...' syntax.

This has been wrong since the pair processing was added (in 9.0),
so back-patch to all supported branches.

Discussion: https://postgr.es/m/19113.1482337898@sss.pgh.pa.us
2016-12-21 17:39:32 -05:00
ec2bc3264e Improve ALTER TABLE documentation
The ALTER TABLE documentation wasn't terribly clear when it came to
which commands could be combined together and what it meant when they
were.

In particular, SET TABLESPACE *can* be combined with other commands,
when it's operating against a single table, but not when multiple tables
are being moved with ALL IN TABLESPACE.  Further, the actions are
applied together but not really in 'parallel', at least today.

Pointed out by: Amit Langote

Improved wording from Tom.

Back-patch to 9.4, where the ALL IN TABLESPACE option was added.

Discussion: https://www.postgresql.org/message-id/14c535b4-13ef-0590-1b98-76af355a0763%40lab.ntt.co.jp
2016-12-21 15:03:44 -05:00
1efc5dba05 Fix dumping of casts and transforms using built-in functions
In pg_dump.c dumpCast() and dumpTransform(), we would happily ignore the
cast or transform if it happened to use a built-in function because we
weren't including the information about built-in functions when querying
pg_proc from getFuncs().

Modify the query in getFuncs() to also gather information about
functions which are used by user-defined casts and transforms (where
"user-defined" means "has an OID >= FirstNormalObjectId").  This also
adds to the TAP regression tests for 9.6 and master to cover these
types of objects.

Back-patch all the way for casts, back to 9.5 for transforms.

Discussion: https://www.postgresql.org/message-id/flat/20160504183952.GE10850%40tamriel.snowman.net
2016-12-21 13:47:18 -05:00
94476436a6 For 8.0 servers, get last built-in oid from pg_database
We didn't start ensuring that all built-in objects had OIDs less than
16384 until 8.1, so for 8.0 servers we still need to query the value out
of pg_database.  We need this, in particular, to distinguish which casts
were built-in and which were user-defined.

For HEAD, we only worry about going back to 8.0, for the back-branches,
we also ensure that 7.0-7.4 work.

Discussion: https://www.postgresql.org/message-id/flat/20160504183952.GE10850%40tamriel.snowman.net
2016-12-21 13:47:18 -05:00
78a98b7674 Fix order of operations in CREATE OR REPLACE VIEW.
When CREATE OR REPLACE VIEW acts on an existing view, don't update the
view options until after the view query has been updated.

This is necessary in the case where CREATE OR REPLACE VIEW is used on
an existing view that is not updatable, and the new view is updatable
and specifies the WITH CHECK OPTION. In this case, attempting to apply
the new options to the view before updating its query fails, because
the options are applied using the ALTER TABLE infrastructure which
checks that WITH CHECK OPTION is only applied to an updatable view.

If new columns are being added to the view, that is also done using
the ALTER TABLE infrastructure, but it is important that that still be
done before updating the view query, because the rules system checks
that the query columns match those on the view relation. Added a
comment to explain that, in case someone is tempted to move that to
where the view options are now being set.

Back-patch to 9.4 where WITH CHECK OPTION was added.

Report: https://postgr.es/m/CAEZATCUp%3Dz%3Ds4SzZjr14bfct_bdJNwMPi-gFi3Xc5k1ntbsAgQ%40mail.gmail.com
2016-12-21 17:02:47 +00:00
bc53d71308 Fix base backup rate limiting in presence of slow i/o
When source i/o on disk was too slow compared to the rate limiting
specified, the system could end up with a negative value for sleep that
it never got out of, which caused rate limiting to effectively be
turned off.

Discussion: https://postgr.es/m/CABUevEy_-e0YvL4ayoX8bH_Ja9w%2BBHoP6jUgdxZuG2nEj3uAfQ%40mail.gmail.com

Analysis by me, patch by Antonin Houska
2016-12-19 10:16:02 +01:00
53140bf22b In contrib/uuid-ossp, #include headers needed for ntohl() and ntohs().
Oversight in commit b8cc8f947.  I just noticed this causes compiler
warnings on FreeBSD, and it really ought to cause warnings elsewhere too:
all references I can find say that <arpa/inet.h> is required for these.
We have a lot of code elsewhere that thinks that both <netinet/in.h>
and <arpa/inet.h> should be included for these functions, so do it that
way here too, even though <arpa/inet.h> ought to be sufficient according
to the references I consulted.

Back-patch to 9.4 where the previous commit landed.
2016-12-17 22:24:35 -05:00
595333ff49 Fix off-by-one in memory allocation for quote_literal_cstr().
The calculation didn't take into account the NULL terminator. That lead
to overwriting the palloc'd buffer by one byte, if the input consists
entirely of backslashes. For example "format('%L', E'\\')".

Fixes bug #14468. Backpatch to all supported versions.

Report: https://www.postgresql.org/message-id/20161216105001.13334.42819%40wrigleys.postgresql.org
2016-12-16 12:53:12 +02:00
492fe48f01 Sync our copy of the timezone library with IANA release tzcode2016j.
This is a trivial update (consisting in fact only in the addition of
a comment).  The point is just to get back to being synced with an
official release of tzcode, rather than some ad-hoc point in their
commit history, which is where commit 1f87181e1 left it.
2016-12-15 14:33:06 -05:00
bed2a0b06b Back-patch fcff8a5751 as a bug fix.
When there is both a serialization failure and a unique violation,
throw the former rather than the latter.  When initially pushed,
this was viewed as a feature to assist application framework
developers, so that they could more accurately determine when to
retry a failed transaction, but a test case presented by Ian
Jackson has shown that this patch can prevent serialization
anomalies in some cases where a unique violation is caught within a
subtransaction, the work of that subtransaction is discarded, and
no error is thrown.  That makes this a bug fix, so it is being
back-patched to all supported branches where it is not already
present (i.e., 9.2 to 9.5).

Discussion: https://postgr.es/m/1481307991-16971-1-git-send-email-ian.jackson@eu.citrix.com
Discussion: https://postgr.es/m/22607.56276.807567.924144@mariner.uk.xensource.com
2016-12-13 19:14:42 -06:00
15b3722700 Use "%option prefix" to set API names in ecpg's lexer.
Back-patch commit 92fb64983 into the pre-9.6 branches.

Without this, ecpg fails to build with the latest version of flex.
It's not unreasonable that people would want to compile our old branches
with recent tools.  Per report from Дилян Палаузов.

Discussion: https://postgr.es/m/d845c1af-e18d-6651-178f-9f08cdf37e10@aegee.org
2016-12-11 18:04:28 -05:00
4262c5b1ee Build backend/parser/scan.l and interfaces/ecpg/preproc/pgc.l standalone.
Back-patch commit 72b1e3a21 into the pre-9.6 branches.

As noted in the original commit, this has some extra benefits: we can
narrow the scope of the -Wno-error flag that's forced on scan.c.  Also,
since these grammar and lexer files are so large, splitting them into
separate build targets should have some advantages in build speed,
particularly in parallel or ccache'd builds.

However, the real reason for doing this now is that it avoids symbol-
redefinition warnings (or worse) with the latest version of flex.
It's not unreasonable that people would want to compile our old branches
with recent tools.  Per report from Дилян Палаузов.

Discussion: https://postgr.es/m/d845c1af-e18d-6651-178f-9f08cdf37e10@aegee.org
2016-12-11 17:44:16 -05:00
c6caa52000 Prevent crash when ts_rewrite() replaces a non-top-level subtree with null.
When ts_rewrite()'s replacement argument is an empty tsquery, it's supposed
to simplify any operator nodes whose operand(s) become NULL; but it failed
to do that reliably, because dropvoidsubtree() only examined the top level
of the result tree.  Rather than make a second recursive pass, let's just
give the responsibility to dofindsubquery() to simplify while it's doing
the main replacement pass.  Per report from Andreas Seltenreich.

Artur Zakirov, with some cosmetic changes by me.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/8737i01dew.fsf@credativ.de
2016-12-11 13:09:57 -05:00
00858728fd Be more careful about Python refcounts while creating exception objects.
PLy_generate_spi_exceptions neglected to do Py_INCREF on the new exception
objects, evidently supposing that PyModule_AddObject would do that --- but
it doesn't.  This left us in a situation where a Python garbage collection
cycle could result in deletion of exception object(s), causing server
crashes or wrong answers if the exception objects are used later in the
session.

In addition, PLy_generate_spi_exceptions didn't bother to test for
a null result from PyErr_NewException, which at best is inconsistent
with the code in PLy_add_exceptions.  And PLy_add_exceptions, while it
did do Py_INCREF on the exceptions it makes, waited to do that till
after some PyModule_AddObject calls, creating a similar risk for
failure if garbage collection happened within those calls.

To fix, refactor to have just one piece of code that creates an
exception object and adds it to the spiexceptions module, bumping the
refcount first.

Also, let's add an additional refcount to represent the pointer we're
going to store in a C global variable or hash table.  This should only
matter if the user does something weird like delete the spiexceptions
Python module, but lack of paranoia has caused us enough problems in
PL/Python already.

The fact that PyModule_AddObject doesn't do a Py_INCREF of its own
explains the need for the Py_INCREF added in commit 4c966d920, so we
can improve the comment about that; also, this means we really want
to do that before not after the PyModule_AddObject call.

The missing Py_INCREF in PLy_generate_spi_exceptions was reported and
diagnosed by Rafa de la Torre; the other fixes by me.  Back-patch
to all supported branches.

Discussion: https://postgr.es/m/CA+Fz15kR1OXZv43mDrJb3XY+1MuQYWhx5kx3ea6BRKQp6ezGkg@mail.gmail.com
2016-12-09 15:27:23 -05:00
6a493adda7 Fix reporting of column typmods for multi-row VALUES constructs.
expandRTE() and get_rte_attribute_type() reported the exprType() and
exprTypmod() values of the expressions in the first row of the VALUES as
being the column type/typmod returned by the VALUES RTE.  That's fine for
the data type, since we coerce all expressions in a column to have the same
common type.  But we don't coerce them to have a common typmod, so it was
possible for rows after the first one to return values that violate the
claimed column typmod.  This leads to the incorrect result seen in bug
#14448 from Hassan Mahmood, as well as some other corner-case misbehaviors.

The desired behavior is the same as we use in other type-unification
cases: report the common typmod if there is one, but otherwise return -1
indicating no particular constraint.

We fixed this in HEAD by deriving the typmods during transformValuesClause
and storing them in the RTE, but that's not a feasible solution in the back
branches.  Instead, just use a brute-force approach of determining the
correct common typmod during expandRTE() and get_rte_attribute_type().
Simple testing says that that doesn't really cost much, at least not in
common cases where expandRTE() is only used once per query.  It turns out
that get_rte_attribute_type() is typically never used at all on VALUES
RTEs, so the inefficiency there is of no great concern.

Report: https://postgr.es/m/20161205143037.4377.60754@wrigleys.postgresql.org
Discussion: https://postgr.es/m/27429.1480968538@sss.pgh.pa.us
2016-12-09 12:01:14 -05:00
581b09c725 Fix crasher bug in array_position(s)
array_position and its cousin array_positions were caching the element
type equality function's FmgrInfo without being careful enough to put it
in a long-lived context.  This is obviously broken but it didn't matter
in most cases; only when using arrays of records (involving record_eq)
it becomes a problem.  The fix is to ensure that the type's equality
function's FmgrInfo is cached in the array_position's flinfo->fn_mcxt
rather than the current memory context.

Apart from record types, the only other case that seems complex enough
to possibly cause the same problem are range types.  I didn't find a way
to reproduce the problem with those, so I only include the test case
submitted with the bug report as regression test.

Bug report and patch: Junseok Yang
Discussion: https://postgr.es/m/CAE+byMupUURYiZ6bKYgMZb9pgV1CYAijJGqWj-90W=nS7uEOeA@mail.gmail.com
Backpatch to 9.5, where array_position appeared.
2016-12-09 12:42:17 -03:00
141ad68964 Log the creation of an init fork unconditionally.
Previously, it was thought that this only needed to be done for the
benefit of possible standbys, so wal_level = minimal skipped it.
But that's not safe, because during crash recovery we might replay
XLOG_DBASE_CREATE or XLOG_TBLSPC_CREATE record which recursively
removes the directory that contains the new init fork.  So log it
always.

The user-visible effect of this bug is that if you create a database
or tablespace, then create an unlogged table, then crash without
checkpointing, then restart, accessing the table will fail, because
the it won't have been properly reset.  This commit fixes that.

Michael Paquier, per a report from Konstantin Knizhnik.  Wording of
the comments per a suggestion from me.
2016-12-08 14:14:12 -05:00
93c78ba19b Restore psql's SIGPIPE setting if popen() fails.
Ancient oversight in PageOutput(): if popen() fails, we'd better reset
the SIGPIPE handler before returning stdout, because ClosePager() won't.
Noticed while fixing the empty-PAGER issue.
2016-12-07 12:39:24 -05:00
370c7a863a Handle empty or all-blank PAGER setting more sanely in psql.
If the PAGER environment variable is set but contains an empty string,
psql would pass it to "sh" which would silently exit, causing whatever
query output we were printing to vanish entirely.  This is quite
mystifying; it took a long time for us to figure out that this was the
cause of Joseph Brenner's trouble report.  Rather than allowing that
to happen, we should treat this as another way to specify "no pager".
(We could alternatively treat it as selecting the default pager, but
it seems more likely that the former is what the user meant to achieve
by setting PAGER this way.)

Nonempty, but all-white-space, PAGER values have the same behavior, and
it's pretty easy to test for that, so let's handle that case the same way.

Most other cases of faulty PAGER values will result in the shell printing
some kind of complaint to stderr, which should be enough to diagnose the
problem, so we don't need to work harder than this.  (Note that there's
been an intentional decision not to be very chatty about apparent failure
returns from the pager process, since that may happen if, eg, the user
quits the pager with control-C or some such.  I'd just as soon not start
splitting hairs about which exit codes might merit making our own report.)

libpq's old PQprint() function was already on board with ignoring empty
PAGER values, but for consistency, make it ignore all-white-space values
as well.

It's been like this a long time, so back-patch to all supported branches.

Discussion: https://postgr.es/m/CAFfgvXWLOE2novHzYjmQK8-J6TmHz42G8f3X0SORM44+stUGmw@mail.gmail.com
2016-12-07 12:19:56 -05:00
f858524ee4 Revert "Permit dump/reload of not-too-large >1GB tuples"
This reverts commit 646655d264.
Per Tom Lane, changing the definition of StringInfoData amounts to an
ABI break, which is unacceptable in back branches.
2016-12-06 12:45:49 -03:00
8606271640 Fix incorrect output from gin_desc().
Previously gin_desc() displayed incorrect output "unknown action 0"
for XLOG_GIN_INSERT and XLOG_GIN_VACUUM_DATA_LEAF_PAGE records with
valid actions. The cause of this problem was that gin_desc() wrongly
used XLogRecGetData() to extract data from those records.
Since they were registered by XLogRegisterBufData(), gin_desc() should
have used XLogRecGetBlockData(), instead, like gin_redo().
Also there were other differences about how to treat XLOG_GIN_INSERT
record between gin_desc() and gin_redo().

This commit fixes gin_desc() routine so that it treats those records
in the same way as gin_redo().

Batch-patch to 9.5 where WAL record format was revamped and
XLogRegisterBufData() was added.

Reported-By: Andres Freund
Reviewed-By: Tom Lane
Discussion: <20160509194645.7lewnpw647zegx2m@alap3.anarazel.de>
2016-12-05 20:32:00 +09:00
25c06a1ed6 Don't mess up pstate->p_next_resno in transformOnConflictClause().
transformOnConflictClause incremented p_next_resno while generating the
phony targetlist for the EXCLUDED pseudo-rel.  Then that field got
incremented some more during transformTargetList, possibly leading to
free_parsestate concluding that we'd overrun the allowed length of a tlist,
as reported by Justin Pryzby.

We could fix this by resetting p_next_resno to 1 after using it for the
EXCLUDED pseudo-rel tlist, but it seems easier and less coupled to other
places if we just don't use that field at all in this loop.  (Note that
this doesn't change anything about the resnos that end up appearing in
the main target list, because those are all replaced with target-column
numbers by updateTargetListEntry.)

In passing, fix incorrect type OID assigned to the whole-row Var for
"EXCLUDED.*" (somehow this escaped having any bad consequences so far,
but it's certainly wrong); remove useless assignment to var->location;
pstrdup the column names in case of a relcache flush; and improve
nearby comments.

Back-patch to 9.5 where ON CONFLICT was introduced.

Report: https://postgr.es/m/20161204163237.GA8030@telsasoft.com
2016-12-04 15:02:48 -05:00
5ab4b2ec4b Make pgwin32_putenv() visit debug CRTs.
This has no effect in the most conventional case, where no relevant DLL
uses a debug build.  For an example where it does matter, given a debug
build of MIT Kerberos, the krb_server_keyfile parameter usually had no
effect.  Since nobody wants a Heisenbug, back-patch to 9.2 (all
supported versions).

Christian Ullrich, reviewed by Michael Paquier.
2016-12-03 15:46:48 -05:00
3cb8bdfef9 Remove wrong CloseHandle() call.
In accordance with its own documentation, invoke CloseHandle() only when
directed in the documentation for the function that furnished the
handle.  GetModuleHandle() does not so direct.  We have been issuing
this call only in the rare event that a CRT DLL contains no "_putenv"
symbol, so lack of bug reports is uninformative.  Back-patch to 9.2 (all
supported versions).

Christian Ullrich, reviewed by Michael Paquier.
2016-12-03 15:46:48 -05:00
c8e18339cc Refine win32env.c cosmetics.
Replace use of plain 0 as a null pointer constant.  In comments, update
terminology and lessen redundancy.  Back-patch to 9.2 (all supported
versions) for the convenience of back-patching the next two commits.

Christian Ullrich and Noah Misch, reviewed (in earlier versions) by
Michael Paquier.
2016-12-03 15:46:47 -05:00
646655d264 Permit dump/reload of not-too-large >1GB tuples
Our documentation states that our maximum field size is 1 GB, and that
our maximum row size of 1.6 TB.  However, while this might be attainable
in theory with enough contortions, it is not workable in practice; for
starters, pg_dump fails to dump tables containing rows larger than 1 GB,
even if individual columns are well below the limit; and even if one
does manage to manufacture a dump file containing a row that large, the
server refuses to load it anyway.

This commit enables dumping and reloading of such tuples, provided two
conditions are met:

1. no single column is larger than 1 GB (in output size -- for bytea
   this includes the formatting overhead)
2. the whole row is not larger than 2 GB

There are three related changes to enable this:

a. StringInfo's API now has two additional functions that allow creating
a string that grows beyond the typical 1GB limit (and "long" string).
ABI compatibility is maintained.  We still limit these strings to 2 GB,
though, for reasons explained below.

b. COPY now uses long StringInfos, so that pg_dump doesn't choke
trying to emit rows longer than 1GB.

c. heap_form_tuple now uses the MCXT_ALLOW_HUGE flag in its allocation
for the input tuple, which means that large tuples are accepted on
input.  Note that at this point we do not apply any further limit to the
input tuple size.

The main reason to limit to 2 GB is that the FE/BE protocol uses 32 bit
length words to describe each row; and because the documentation is
ambiguous on its signedness and libpq does consider it signed, we cannot
use the highest-order bit.  Additionally, the StringInfo API uses "int"
(which is 4 bytes wide in most platforms) in many places, so we'd need
to change that API too in order to improve, which has lots of fallout.

Backpatch to 9.5, which is the oldest that has
MemoryContextAllocExtended, a necessary piece of infrastructure.  We
could apply to 9.4 with very minimal additional effort, but any further
than that would require backpatching "huge" allocations too.

This is the largest set of changes we could find that can be
back-patched without breaking compatibility with existing systems.
Fixing a bigger set of problems (for example, dumping tuples bigger than
2GB, or dumping fields bigger than 1GB) would require changing the FE/BE
protocol and/or changing the StringInfo API in an ABI-incompatible way,
neither of which would be back-patchable.

Authors: Daniel Vérité, Álvaro Herrera
Reviewed by: Tomas Vondra
Discussion: https://postgr.es/m/20160229183023.GA286012@alvherre.pgsql
2016-12-02 00:34:01 -03:00
bb389ad8cd Doc: improve description of trim() and related functions.
Per bug #14441 from Mark Pether, the documentation could be misread,
mainly because some of the examples failed to show what happens with
a multicharacter "characters to trim" string.  Also, while the text
description in most of these entries was fairly clear that the
"characters" argument is a set of characters not a substring to match,
some of them used variant wording that was a bit less clear.
trim() itself suffered from both deficiencies and was thus pretty
misinterpretable.

Also fix failure to explain which of LEADING/TRAILING/BOTH is the
default.

Discussion: https://postgr.es/m/20161130011710.6539.53657@wrigleys.postgresql.org
2016-11-30 13:34:14 -05:00
6c1a257fc6 Clarify pg_dump -b documentation
The documentation around the -b/--blobs option to pg_dump seemed to
imply that it might be possible to add blobs to a "schema-only" dump or
similar.  Clarify that blobs are data and therefore will only be
included in dumps where data is being included, even when -b is used to
request blobs be included.

The -b option has been around since before 9.2, so back-patch to all
supported branches.

Discussion: https://postgr.es/m/20161119173316.GA13284@tamriel.snowman.net
2016-11-29 10:35:10 -05:00
eb516e87ea Mention server start requirement for ssl parameters
Fix that the documentation for three ssl related parameters did not
specify that they can only be changed at server start.

Michael Paquier
2016-11-27 17:11:12 +01:00
576bd360b2 Fix test about ignoring extension dependencies during extension scripts.
Commit 08dd23cec introduced an exception to the rule that extension member
objects can only be dropped as part of dropping the whole extension,
intending to allow such drops while running the extension's own creation or
update scripts.  However, the exception was only applied at the outermost
recursion level, because it was modeled on a pre-existing check to ignore
dependencies on objects listed in pendingObjects.  Bug #14434 from Philippe
Beaudoin shows that this is inadequate: in some cases we can reach an
extension member object by recursion from another one.  (The bug concerns
the serial-sequence case; I'm not sure if there are other cases, but there
might well be.)

To fix, revert 08dd23cec's changes to findDependentObjects() and instead
apply the creating_extension exception regardless of stack level.

Having seen this example, I'm a bit suspicious that the pendingObjects
logic is also wrong and such cases should likewise be allowed at any
recursion level.  However, changing that would interact in subtle ways
with the recursion logic (at least it would need to be moved to after the
recursing-from check).  Given that the code's been like that a long time,
I'll refrain from touching it without a clear example showing it's wrong.

Back-patch to all active branches.  In HEAD and 9.6, where suitable
test infrastructure exists, add a regression test case based on the
bug report.

Report: <20161125151448.6529.33039@wrigleys.postgresql.org>
Discussion: <13224.1480177514@sss.pgh.pa.us>
2016-11-26 13:31:35 -05:00
6cbe84c826 Check for pending trigger events on far end when dropping an FK constraint.
When dropping a foreign key constraint with ALTER TABLE DROP CONSTRAINT,
we refuse the drop if there are any pending trigger events on the named
table; this ensures that we won't remove the pg_trigger row that will be
consulted by those events.  But we should make the same check for the
referenced relation, else we might remove a due-to-be-referenced pg_trigger
row for that relation too, resulting in "could not find trigger NNN" or
"relation NNN has no triggers" errors at commit.  Per bug #14431 from
Benjie Gillam.  Back-patch to all supported branches.

Report: <20161124114911.6530.31200@wrigleys.postgresql.org>
2016-11-25 13:44:48 -05:00
7816d13563 Fix commit_ts for FrozenXid and BootstrapXid
Previously, requesting commit timestamp for transactions
FrozenTransactionId and BootstrapTransactionId resulted in an error.
But since those values can validly appear in committed tuples' Xmin,
this behavior is unhelpful and error prone: each caller would have to
special-case those values before requesting timestamp data for an Xid.
We already have a perfectly good interface for returning "the Xid you
requested is too old for us to have commit TS data for it", so let's use
that instead.

Backpatch to 9.5, where commit timestamps appeared.

Author: Craig Ringer
Discussion: https://www.postgresql.org/message-id/CAMsr+YFM5Q=+ry3mKvWEqRTxrB0iU3qUSRnS28nz6FJYtBwhJg@mail.gmail.com
2016-11-24 15:39:55 -03:00
e0375d77b6 Make sure ALTER TABLE preserves index tablespaces.
When rebuilding an existing index, ALTER TABLE correctly kept the
physical file in the same tablespace, but it messed up the pg_class
entry if the index had been in the database's default tablespace
and "default_tablespace" was set to some non-default tablespace.
This led to an inaccessible index.

Fix by fixing pg_get_indexdef_string() to always include a tablespace
clause, whether or not the index is in the default tablespace.  The
previous behavior was installed in commit 537e92e41, and I think it just
wasn't thought through very clearly; certainly the possible effect of
default_tablespace wasn't considered.  There's some risk in changing the
behavior of this function, but there are no other call sites in the core
code.  Even if it's being used by some third party extension, it's fairly
hard to envision a usage that is okay with a tablespace clause being
appended some of the time but can't handle it being appended all the time.

Back-patch to all supported versions.

Code fix by me, investigation and test cases by Michael Paquier.

Discussion: <1479294998857-5930602.post@n3.nabble.com>
2016-11-23 13:45:56 -05:00
3de257f602 Doc: in back branches, don't call it a row constructor if it isn't really.
Before commit 906bfcad7, we were not actually processing the righthand
side of a multiple-column assignment in UPDATE as a row constructor:
it was just a parenthesized list of expressions.  Call it that rather
than risking confusion by people who would expect the documented behaviors
of row constructors to apply.

Back-patch to 9.5; before that, the text correctly described the construct
as a "list of independent expressions".

Discussion: <16288.1479610770@sss.pgh.pa.us>
2016-11-22 18:07:43 -05:00
ff9730aa15 Doc: improve documentation about composite-value usage.
Create a section specifically for the syntactic rules around whole-row
variable usage, such as expansion of "foo.*".  This was previously
documented only haphazardly, with some critical info buried in
unexpected places like xfunc-sql-composite-functions.  Per repeated
questions in different mailing lists.

Discussion: <16288.1479610770@sss.pgh.pa.us>
2016-11-22 17:56:16 -05:00
5799554449 Doc: add a section in Part II concerning RETURNING.
There are assorted references to RETURNING in Part II, but nothing
that would qualify as an explanation of the feature, which seems
like an oversight considering how useful it is.  Add something.

Noted while looking for a place to point a cross-reference to ...
2016-11-22 14:03:09 -05:00
89c2d81438 Make contrib/test_decoding regression tests safe for CZ locale.
A little COLLATE "C" goes a long way.

Pavel Stehule, per suggestion from Craig Ringer

Discussion: <CAFj8pRA8nJZcozgxN=RMSqMmKuHVOkcGAAKPKdFeiMWGDSUDLA@mail.gmail.com>
2016-11-21 20:39:28 -05:00
a0c15427df Fix PGLC_localeconv() to handle errors better.
The code was intentionally not very careful about leaking strdup'd
strings in case of an error.  That was forgivable probably, but it
also failed to notice strdup() failures, which could lead to subsequent
null-pointer-dereference crashes, since many callers unsurprisingly
didn't check for null pointers in the struct lconv fields.  An even
worse problem is that it could throw error while we were setlocale'd
to a non-C locale, causing unwanted behavior in subsequent libc calls.

Rewrite to ensure that we cannot throw elog(ERROR) until after we've
restored the previous locale settings, or at least attempted to.
(I'm sorely tempted to make restore failure be a FATAL error, but
will refrain for the moment.)  Having done that, it's not much more
work to ensure that we clean up strdup'd storage on the way out, too.

This code is substantially the same in all supported branches, so
back-patch all the way.

Michael Paquier and Tom Lane

Discussion: <CAB7nPqRMbGqa_mesopcn4MPyTs34eqtVEK7ELYxvvV=oqS00YA@mail.gmail.com>
2016-11-21 18:21:56 -05:00
aeb5e82427 Prevent multicolumn expansion of "foo.*" in an UPDATE source expression.
Because we use transformTargetList() for UPDATE as well as SELECT
tlists, the code accidentally tried to expand a "*" reference into
several columns.  This is nonsensical, because the UPDATE syntax
provides exactly one target column to put the value into.  The
immediate result was that transformUpdateTargetList() got confused
and reported "UPDATE target count mismatch --- internal error".
It seems better to treat such a reference as a plain whole-row
variable, as it would be in other contexts.  (This could produce
useful results when the target column is of composite type.)

Fix by tweaking transformTargetList() to perform *-expansion only
conditionally, depending on its exprKind parameter.

Back-patch to 9.3.  The problem exists further back, but a fix would be
much more invasive before that, because transformTargetList() wasn't
told what kind of list it was working on.  Doesn't seem worth the
trouble given the lack of field reports.  (I only noticed it because
I was checking the code while trying to improve the documentation about
how we handle "foo.*".)

Discussion: <4308.1479595330@sss.pgh.pa.us>
2016-11-20 14:26:19 -05:00
b9ee42e70a Code review for GUC serialization/deserialization code.
The serialization code dumped core for a string-valued GUC whose value
is NULL, which is a legal state.  The infrastructure isn't capable of
transmitting that state exactly, but fortunately, transmitting an empty
string instead should be close enough (compare, eg, commit e45e990e4).

The code potentially underestimated the space required to format a
real-valued variable, both because it made an unwarranted assumption that
%g output would never be longer than %e output, and because it didn't count
right even for %e format.  In practice this would pretty much always be
masked by overestimates for other variables, but it's still wrong.

Also fix boundary-case error in read_gucstate, incorrect handling of the
case where guc_sourcefile is non-NULL but zero length (not clear that can
happen, but if it did, this code would get totally confused), and
confusingly useless check for a NULL result from read_gucstate.

Andreas Seltenreich discovered the core dump; other issues noted while
reading nearby code.  Back-patch to 9.5 where this code was introduced.

Michael Paquier and Tom Lane

Discussion: <871sy78wno.fsf@credativ.de>
2016-11-19 14:26:20 -05:00
a7864037d8 Improve pg_dump/pg_restore --create --if-exists logic.
Teach it not to complain if the dropStmt attached to an archive entry
is actually spelled CREATE OR REPLACE VIEW, since that will happen due to
an upcoming bug fix.  Also, if it doesn't recognize a dropStmt, have it
print a WARNING and then emit the dropStmt unmodified.  That seems like a
much saner behavior than Assert'ing or dumping core due to a null-pointer
dereference, which is what would happen before :-(.

Back-patch to 9.4 where this option was introduced.

Discussion: <19092.1479325184@sss.pgh.pa.us>
2016-11-17 14:59:23 -05:00