Commit Graph

8797 Commits

Author SHA1 Message Date
Tom Lane a1a789eb5a In walreceiver, don't try to do ereport() in a signal handler.
This is quite unsafe, even for the case of ereport(FATAL) where we won't
return control to the interrupted code, and despite this code's use of
a flag to restrict the areas where we'd try to do it.  It's possible
for example that we interrupt malloc or free while that's holding a lock
that's meant to protect against cross-thread interference.  Then, any
attempt to do malloc or free within ereport() will result in a deadlock,
preventing the walreceiver process from exiting in response to SIGTERM.
We hypothesize that this explains some hard-to-reproduce failures seen
in the buildfarm.

Hence, get rid of the immediate-exit code in WalRcvShutdownHandler,
as well as the logic associated with WalRcvImmediateInterruptOK.
Instead, we need to take care that potentially-blocking operations
in the walreceiver's data transmission logic (libpqwalreceiver.c)
will respond reasonably promptly to the process's latch becoming
set and then call ProcessWalRcvInterrupts.  Much of the needed code
for that was already present in libpqwalreceiver.c.  I refactored
things a bit so that all the uses of PQgetResult use latch-aware
waiting, but didn't need to do much more.

These changes should be enough to ensure that libpqwalreceiver.c
will respond promptly to SIGTERM whenever it's waiting to receive
data.  In principle, it could block for a long time while waiting
to send data too, and this patch does nothing to guard against that.
I think that that hazard is mostly theoretical though: such blocking
should occur only if we fill the kernel's data transmission buffers,
and we don't generally send enough data to make that happen without
waiting for input.  If we find out that the hazard isn't just
theoretical, we could fix it by using PQsetnonblocking, but that
would require more ticklish changes than I care to make now.

This is a bug fix, but it seems like too big a change to push into
the back branches without much more testing than there's time for
right now.  Perhaps we'll back-patch once we have more confidence
in the change.

Patch by me; thanks to Thomas Munro for review.

Discussion: https://postgr.es/m/20190416070119.GK2673@paquier.xyz
2019-04-29 12:26:07 -04:00
Tom Lane c3f67ed6e4 Do pre-release housekeeping on catalog data, and fix jsonpath send/recv.
Run renumber_oids.pl to move high-numbered OIDs down, as per pre-beta
tasks specified by RELEASE_CHANGES.  (The only change is 8394 -> 3428.)

Also run reformat_dat_file.pl while I'm here.

While looking at the reformat diffs, I chanced to notice that type
jsonpath had typsend and typreceive = '-', which surely is not the
intention given that jsonpath_send and jsonpath_recv exist.
Fix that.  It's safe to assume that these functions have never been
tested :-(.  I didn't try, but somebody should.
2019-04-28 17:16:50 -04:00
Alvaro Herrera 87259588d0 Fix tablespace inheritance for partitioned rels
Commit ca4103025d left a few loose ends.  The most important one
(broken pg_dump output) is already fixed by virtue of commit
3b23552ad8, but some things remained:

* When ALTER TABLE rewrites tables, the indexes must remain in the
  tablespace they were originally in.  This didn't work because
  index recreation during ALTER TABLE runs manufactured SQL (yuck),
  which runs afoul of default_tablespace in competition with the parent
  relation tablespace.  To fix, reset default_tablespace to the empty
  string temporarily, and add the TABLESPACE clause as appropriate.

* Setting a partitioned rel's tablespace to the database default is
  confusing; if it worked, it would direct the partitions to that
  tablespace regardless of default_tablespace.  But in reality it does
  not work, and making it work is a larger project.  Therefore, throw
  an error when this condition is detected, to alert the unwary.

Add some docs and tests, too.

Author: Álvaro Herrera
Discussion: https://postgr.es/m/CAKJS1f_1c260nOt_vBJ067AZ3JXptXVRohDVMLEBmudX1YEx-A@mail.gmail.com
2019-04-25 10:31:32 -04:00
Andres Freund fdc7efcc30 Allow pg_class xid & multixid horizons to not be set.
This allows table AMs that don't need these horizons. This was already
documented in the tableam relation_set_new_filenode callback, but an
assert prevented if from actually working (the test AM code contained
the change itself). Defang the asserts in the general code, and move
the stronger ones into heap AM.

Relatedly, after CLUSTER/VACUUM, we'd always assign a relfrozenxid /
relminmxid. Change the table_relation_copy_for_cluster() interface to
allow the AM to overwrite the horizons that get set on the pg_class
entry.  This'd also in the future allow AMs like heap to compute a
relfrozenxid during rewrite that's the table's actual minimum rather
than a pre-determined value.  Arguably it'd have been better to move
the whole computation / setting of those values into the callback, but
it seems likely that for other reasons it'd be better to be able to
use one value to vacuum/cluster multiple tables (e.g. a toast's
horizon shouldn't be different than the table's).

Reported-By: Heikki Linnakangas
Author: Andres Freund
Discussion: https://postgr.es/m/9a7fb9cc-2419-5db7-8840-ddc10c93f122@iki.fi
2019-04-23 21:42:12 -07:00
Tom Lane e0fb4c9d01 Remove useless comment.
Commit e439c6f0c removed IndexStmt.relationId, but not the comment
that had been added to explain it.  Said comment was therefore
very confusing.
2019-04-23 17:17:26 -04:00
Peter Geoghegan 9b10926263 Prevent O(N^2) unique index insertion edge case.
Commit dd299df8 made nbtree treat heap TID as a tiebreaker column,
establishing the principle that there is only one correct location (page
and page offset number) for every index tuple, no matter what.
Insertions of tuples into non-unique indexes proceed as if heap TID
(scan key's scantid) is just another user-attribute value, but
insertions into unique indexes are more delicate.  The TID value in
scantid must initially be omitted to ensure that the unique index
insertion visits every leaf page that duplicates could be on.  The
scantid is set once again after unique checking finishes successfully,
which can force _bt_findinsertloc() to step right one or more times, to
locate the leaf page that the new tuple must be inserted on.

Stepping right within _bt_findinsertloc() was assumed to occur no more
frequently than stepping right within _bt_check_unique(), but there was
one important case where that assumption was incorrect: inserting a
"duplicate" with NULL values.  Since _bt_check_unique() didn't do any
real work in this case, it wasn't appropriate for _bt_findinsertloc() to
behave as if it was finishing off a conventional unique insertion, where
any existing physical duplicate must be dead or recently dead.
_bt_findinsertloc() might have to grovel through a substantial portion
of all of the leaf pages in the index to insert a single tuple, even
when there were no dead tuples.

To fix, treat insertions of tuples with NULLs into a unique index as if
they were insertions into a non-unique index: never unset scantid before
calling _bt_search() to descend the tree, and bypass _bt_check_unique()
entirely.  _bt_check_unique() is no longer responsible for incoming
tuples with NULL values.

Discussion: https://postgr.es/m/CAH2-Wzm08nr+JPx4jMOa9CGqxWYDQ-_D4wtPBiKghXAUiUy-nQ@mail.gmail.com
2019-04-23 10:33:57 -07:00
Tom Lane f4a3fdfbdc Avoid order-of-execution problems with ALTER TABLE ADD PRIMARY KEY.
Up to now, DefineIndex() was responsible for adding attnotnull constraints
to the columns of a primary key, in any case where it hadn't been
convenient for transformIndexConstraint() to mark those columns as
is_not_null.  It (or rather its minion index_check_primary_key) did this
by executing an ALTER TABLE SET NOT NULL command for the target table.

The trouble with this solution is that if we're creating the index due
to ALTER TABLE ADD PRIMARY KEY, and the outer ALTER TABLE has additional
sub-commands, the inner ALTER TABLE's operations executed at the wrong
time with respect to the outer ALTER TABLE's operations.  In particular,
the inner ALTER would perform a validation scan at a point where the
table's storage might be inconsistent with its catalog entries.  (This is
on the hairy edge of being a security problem, but AFAICS it isn't one
because the inner scan would only be interested in the tuples' null
bitmaps.)  This can result in unexpected failures, such as the one seen
in bug #15580 from Allison Kaptur.

To fix, let's remove the attempt to do SET NOT NULL from DefineIndex(),
reducing index_check_primary_key's role to verifying that the columns are
already not null.  (It shouldn't ever see such a case, but it seems wise
to keep the check for safety.)  Instead, make transformIndexConstraint()
generate ALTER TABLE SET NOT NULL subcommands to be executed ahead of
the ADD PRIMARY KEY operation in every case where it can't force the
column to be created already-not-null.  This requires only minor surgery
in parse_utilcmd.c, and it makes for a much more satisfying spec for
transformIndexConstraint(): it's no longer having to take it on faith
that someone else will handle addition of NOT NULL constraints.

To make that work, we have to move the execution of AT_SetNotNull into
an ALTER pass that executes ahead of AT_PASS_ADD_INDEX.  I moved it to
AT_PASS_COL_ATTRS, and put that after AT_PASS_ADD_COL to avoid failure
when the column is being added in the same command.  This incidentally
fixes a bug in the only previous usage of AT_PASS_COL_ATTRS, for
AT_SetIdentity: it didn't work either for a newly-added column.

Playing around with this exposed a separate bug in ALTER TABLE ONLY ...
ADD PRIMARY KEY for partitioned tables.  The intent of the ONLY modifier
in that context is to prevent doing anything that would require holding
lock for a long time --- but the implied SET NOT NULL would recurse to
the child partitions, and do an expensive validation scan for any child
where the column(s) were not already NOT NULL.  To fix that, invent a
new ALTER subcommand AT_CheckNotNull that just insists that a child
column be already NOT NULL, and apply that, not AT_SetNotNull, when
recursing to children in this scenario.  This results in a slightly laxer
definition of ALTER TABLE ONLY ... SET NOT NULL for partitioned tables,
too: that command will now work as long as all children are already NOT
NULL, whereas before it just threw up its hands if there were any
partitions.

In passing, clean up the API of generateClonedIndexStmt(): remove a
useless argument, ensure that the output argument is not left undefined,
update the header comment.

A small side effect of this change is that no-such-column errors in ALTER
TABLE ADD PRIMARY KEY now produce a different message that includes the
table name, because they are now detected by the SET NOT NULL step which
has historically worded its error that way.  That seems fine to me, so
I didn't make any effort to avoid the wording change.

The basic bug #15580 is of very long standing, and these other bugs
aren't new in v12 either.  However, this is a pretty significant change
in the way ALTER TABLE ADD PRIMARY KEY works.  On balance it seems best
not to back-patch, at least not till we get some more confidence that
this patch has no new bugs.

Patch by me, but thanks to Jie Zhang for a preliminary version.

Discussion: https://postgr.es/m/15580-d1a6de5a3d65da51@postgresql.org
Discussion: https://postgr.es/m/1396E95157071C4EBBA51892C5368521017F2E6E63@G08CNEXMBPEKD02.g08.fujitsu.local
2019-04-23 12:25:27 -04:00
Michael Paquier ccae190b91 Fix detection of passwords hashed with MD5 or SCRAM-SHA-256
This commit fixes a couple of issues related to the way password
verifiers hashed with MD5 or SCRAM-SHA-256 are detected, leading to
being able to store in catalogs passwords which do not follow the
supported hash formats:
- A MD5-hashed entry was checked based on if its header uses "md5" and
if the string length matches what is expected.  Unfortunately the code
never checked if the hash only used hexadecimal characters, as reported
by Tom Lane.
- A SCRAM-hashed entry was checked based on only its header, which
should be "SCRAM-SHA-256$", but it never checked for any fields
afterwards, as reported by Jonathan Katz.

Backpatch down to v10, which is where SCRAM has been introduced, and
where password verifiers in plain format have been removed.

Author: Jonathan Katz
Reviewed-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/016deb6b-1f0a-8e9f-1833-a8675b170aa9@postgresql.org
Backpatch-through: 10
2019-04-23 15:43:21 +09:00
Andres Freund b5f58cf213 Convert gist to compute page level xid horizon on primary.
Due to parallel development, gist added the missing conflict
information in c952eae52a, while 558a9165e0 moved that computation
to the primary for the index types that already had it.  Thus adapt
gist to also compute on the primary, using
index_compute_xid_horizon_for_tuples() instead of its own copy of the
logic.

This also adds pg_waldump support for XLOG_GIST_DELETE records, which
previously was not properly present.

Bumps WAL version.

Author: Andres Freund
Discussion: https://postgr.es/m/20190406050243.bszosdg4buvabfrt@alap3.anarazel.de
2019-04-22 14:28:30 -07:00
Tomas Vondra d08c44f7a4 Fix mvdistinct and dependencies size calculations
The formulas used to calculate size while (de)serializing mvndistinct
and functional dependencies were based on offset() of the structs. But
that is incorrect, because the structures are not copied directly, we
we copy the individual fields directly.

At the moment this works fine, because there is no alignment padding
on any platform we support. But it might break if we ever added some
fields into any of the structs, for example. It's also confusing.

Fixed by reworking the macros to directly sum sizes of serialized
fields. The macros are now useful only for serialiation, so there is
no point in keeping them in the public header file. So make them
private by moving them to the .c files.

Also adds a couple more asserts to check the serialization, and fixes
an incorrect allocation of MVDependency instead of (MVDependency *).

Reported-By: Tom Lane
Discussion: https://postgr.es/m/29785.1555365602@sss.pgh.pa.us
2019-04-21 20:23:34 +02:00
Andres Freund b8b94ea129 Fix slot type issue for fuzzy distance index scan over out-of-core table AM.
For amcanreorderby scans the nodeIndexscan.c's reorder queue holds
heap tuples, but the underlying table likely does not. Before this fix
we'd return different types of slots, depending on whether the tuple
came from the reorder queue, or from the index + table.

While that could be fixed by signalling that the node doesn't return a
fixed type of slot, it seems better to instead remove the separate
slot for the reorder queue, and use ExecForceStoreHeapTuple() to store
tuples from the queue. It's not particularly common to need
reordering, after all.

This reverts most of the iss_ReorderQueueSlot related changes to
nodeIndexscan.c made in 1a0586de36, except that now
ExecForceStoreHeapTuple() is used instead of ExecStoreHeapTuple().

Noticed when testing zheap against the in-core version of tableam.

Author: Andres Freund
2019-04-19 11:42:37 -07:00
Andres Freund 88e6ad3054 Fix two memory leaks around force-storing tuples in slots.
As reported by Tom, when ExecStoreMinimalTuple() had to perform a
conversion to store the minimal tuple in the slot, it forgot to
respect the shouldFree flag, and leaked the tuple into the current
memory context if true.  Fix that by freeing the tuple in that case.

Looking at the relevant code made me (Andres) realize that not having
the shouldFree parameter to ExecForceStoreHeapTuple() was a bad
idea. Some callers had to locally implement the necessary logic, and
in one case it was missing, creating a potential per-group leak in
non-hashed aggregation.

The choice to not free the tuple in ExecComputeStoredGenerated() is
not pretty, but not introduced by this commit - I'll start a separate
discussion about it.

Reported-By: Tom Lane
Discussion: https://postgr.es/m/366.1555382816@sss.pgh.pa.us
2019-04-19 11:39:56 -07:00
Tom Lane dde7fb7836 Use [FLEXIBLE_ARRAY_MEMBER] not [1] in MultiSortSupportData.
This struct seems to have not gotten the word about preferred
coding style for variable-length arrays.
2019-04-15 19:32:44 -04:00
Tom Lane 5f1433ac5e Prevent memory leaks associated with relcache rd_partcheck structures.
The original coding of generate_partition_qual() just copied the list
of predicate expressions into the global CacheMemoryContext, making it
effectively impossible to clean up when the owning relcache entry is
destroyed --- the relevant code in RelationDestroyRelation() only managed
to free the topmost List header :-(.  This resulted in a session-lifespan
memory leak whenever a table partition's relcache entry is rebuilt.
Fortunately, that's not normally a large data structure, and rebuilds
shouldn't occur all that often in production situations; but this is
still a bug worth fixing back to v10 where the code was introduced.

To fix, put the cached expression tree into its own small memory context,
as we do with other complicated substructures of relcache entries.
Also, deal more honestly with the case that a partition has an empty
partcheck list; while that probably isn't a case that's very interesting
for production use, it's legal.

In passing, clarify comments about how partitioning-related relcache
data structures are managed, and add some Asserts that we're not leaking
old copies when we overwrite these data fields.

Amit Langote and Tom Lane

Discussion: https://postgr.es/m/7961.1552498252@sss.pgh.pa.us
2019-04-13 13:22:26 -04:00
Noah Misch c098509927 Consistently test for in-use shared memory.
postmaster startup scrutinizes any shared memory segment recorded in
postmaster.pid, exiting if that segment matches the current data
directory and has an attached process.  When the postmaster.pid file was
missing, a starting postmaster used weaker checks.  Change to use the
same checks in both scenarios.  This increases the chance of a startup
failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1
postmaster.pid` && rm postmaster.pid && pg_ctl -w start".  A postmaster
will no longer stop if shmat() of an old segment fails with EACCES.  A
postmaster will no longer recycle segments pertaining to other data
directories.  That's good for production, but it's bad for integration
tests that crash a postmaster and immediately delete its data directory.
Such a test now leaks a segment indefinitely.  No "make check-world"
test does that.  win32_shmem.c already avoided all these problems.  In
9.6 and later, enhance PostgresNode to facilitate testing.  Back-patch
to 9.4 (all supported versions).

Reviewed (in earlier versions) by Daniel Gustafsson and Kyotaro HORIGUCHI.

Discussion: https://postgr.es/m/20190408064141.GA2016666@rfd.leadboat.com
2019-04-12 22:36:38 -07:00
Magnus Hagander 77bd49adba Show shared object statistics in pg_stat_database
This adds a row to the pg_stat_database view with datoid 0 and datname
NULL for those objects that are not in a database. This was added
particularly for checksums, but we were already tracking more satistics
for these objects, just not returning it.

Also add a checksum_last_failure column that holds the timestamptz of
the last checksum failure that occurred in a database (or in a
non-dataabase file), if any.

Author: Julien Rouhaud <rjuju123@gmail.com>
2019-04-12 14:04:50 +02:00
Peter Eisentraut ef6f30fe77 Fix REINDEX CONCURRENTLY of partitions
In case of a partition index, when swapping the old and new index, we
also need to attach the new index as a partition and detach the old
one.  Also, to handle partition indexes, we not only need to change
dependencies referencing the index, but also dependencies of the index
referencing something else.  The previous code did this only
specifically for a constraint, but we also need to do this for
partitioned indexes.  So instead write a generic function that does it
for all dependencies.

Author: Michael Paquier <michael@paquier.xyz>
Author: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/DF4PR8401MB11964EDB77C860078C343BEBEE5A0%40DF4PR8401MB1196.NAMPRD84.PROD.OUTLOOK.COM#154df1fedb735190a773481765f7b874
2019-04-12 08:36:05 +02:00
Amit Kapila bdf35744bd Avoid counting transaction stats for parallel worker cooperating
transaction.

The transaction that is initiated by the parallel worker to cooperate
with the actual transaction started by the main backend to complete the
query execution should not be counted as a separate transaction.  The
other internal transactions started and committed by the parallel worker
are still counted as separate transactions as we that is what we do in
other places like autovacuum.

This will partially fix the bloat in transaction stats due to additional
transactions performed by parallel workers.  For a complete fix, we need to
decide how we want to show all the transactions that are started internally
for various operations and that is a matter of separate patch.

Reported-by: Haribabu Kommi
Author: Haribabu Kommi
Reviewed-by: Amit Kapila, Jamison Kirk and Rahila Syed
Backpatch-through: 9.6
Discussion: https://postgr.es/m/CAJrrPGc9=jKXuScvNyQ+VNhO0FZk7LLAShAJRyZjnedd2D61EQ@mail.gmail.com
2019-04-10 08:24:15 +05:30
Thomas Munro d614aae02e Improve comment in sync.h.
Per off-list complaint from Andres Freund.
2019-04-10 12:49:49 +12:00
Noah Misch 617dc6d299 Avoid "could not reattach" by providing space for concurrent allocation.
We've long had reports of intermittent "could not reattach to shared
memory" errors on Windows.  Buildfarm member dory fails that way when
PGSharedMemoryReAttach() execution overlaps with creation of a thread
for the process's "default thread pool".  Fix that by providing a second
region to receive asynchronous allocations that would otherwise intrude
into UsedShmemSegAddr.  In pgwin32_ReserveSharedMemoryRegion(), stop
trying to free reservations landing at incorrect addresses; the caller's
next step has been to terminate the affected process.  Back-patch to 9.4
(all supported versions).

Reviewed by Tom Lane.  He also did much of the prerequisite research;
see commit bcbf2346d6.

Discussion: https://postgr.es/m/20190402135442.GA1173872@rfd.leadboat.com
2019-04-08 21:39:00 -07:00
Andres Freund 6421011ea2 tableam: comment and formatting fixes.
Author: Heikki Linnakangas
Discussion: https://postgr.es/m/9a7fb9cc-2419-5db7-8840-ddc10c93f122@iki.fi
2019-04-08 16:24:36 -07:00
Fujii Masao 119dcfad98 Add vacuum_truncate reloption.
vacuum_truncate controls whether vacuum tries to truncate off
any empty pages at the end of the table. Previously vacuum always
tried to do the truncation. However, the truncation could cause
some problems; for example, ACCESS EXCLUSIVE lock needs to
be taken on the table during the truncation and can cause
the query cancellation on the standby even if hot_standby_feedback
is true. Setting this reloption to false can be helpful to avoid
such problems.

Author: Tsunakawa Takayuki
Reviewed-By: Julien Rouhaud, Masahiko Sawada, Michael Paquier, Kirk Jamison and Fujii Masao
Discussion: https://postgr.es/m/CAHGQGwE5UqFqSq1=kV3QtTUtXphTdyHA-8rAj4A=Y+e4kyp3BQ@mail.gmail.com
2019-04-08 16:43:57 +09:00
Andres Freund 41f5e04aec Fix a number of issues around modifying a previously updated row.
This commit fixes three, unfortunately related, issues:

1) Since 5db6df0c01, the introduction of DML via tableam, it was
   possible to trigger "ERROR: unexpected table_lock_tuple status: 1"
   when updating a row that was previously updated in the same
   transaction - but only when the previously updated row was before
   updated in a concurrent transaction (and READ COMMITTED was
   used). The reason for that was that that case simply wasn't
   expected. Fixing that lead to:

2) Even before the above commit, there were error checks (introduced
   in 6868ed7491) preventing a row being updated by different
   commands within the same statement (say in a function called by an
   UPDATE) - but that check wasn't performed when the row was first
   updated in a concurrent transaction - instead the second update was
   silently skipped in that case. After this change we throw the same
   error as we'd without the concurrent transaction.

3) The error messages (introduced in 6868ed7491) preventing such
   updates emitted the same error message for both DELETE and
   UPDATE ("tuple to be updated was already modified by an operation
   triggered by the current command"). While that could be changed
   separately, it made it hard to write tests that verify the correct
   correct behavior of the code.

This commit changes heap's implementation of table_lock_tuple() to
return TM_SelfModified instead of TM_Invisible (previously loosely
modeled after EvalPlanQualFetch), and teaches nodeModifyTable.c to
handle that in response to table_lock_tuple() and not just in response
to table_(delete|update).

Additionally it fixes the wrong error message (see 3 above). The
comment for table_lock_tuple() is also adjusted to state that
TM_Deleted won't return information in TM_FailureData - it'll not
always be available.

This also adds tests to ensure that DELETE/UPDATE correctly error out
when affecting a row that concurrently was modified by another
transaction.

Author: Andres Freund
Reported-By: Tom Lane, when investigating a bug bug fix to another bug
    by Amit Langote
Discussion: https://postgr.es/m/19321.1554567786@sss.pgh.pa.us
2019-04-07 22:14:47 -07:00
Peter Eisentraut 03f9e5cba0 Report progress of REINDEX operations
This uses the same infrastructure that the CREATE INDEX progress
reporting uses.  Add a column to pg_stat_progress_create_index to
report the OID of the index being worked on.  This was not necessary
for CREATE INDEX, but it's useful for REINDEX.

Also edit the phase descriptions a bit to be more consistent with the
source code comments.

Discussion: https://www.postgresql.org/message-id/ef6a6757-c36a-9e81-123f-13b19e36b7d7%402ndquadrant.com
2019-04-07 12:35:29 +02:00
Peter Eisentraut 106f2eb664 Cast pg_stat_progress_cluster.cluster_index_relid to oid
It's tracked internally as bigint, but when presented to the user it
should be oid.
2019-04-07 10:31:32 +02:00
Michael Paquier 249d649996 Add support TCP user timeout in libpq and the backend server
Similarly to the set of parameters for keepalive, a connection parameter
for libpq is added as well as a backend GUC, called tcp_user_timeout.

Increasing the TCP user timeout is useful to allow a connection to
survive extended periods without end-to-end connection, and decreasing
it allows application to fail faster.  By default, the parameter is 0,
which makes the connection use the system default, and follows a logic
close to the keepalive parameters in its handling.  When connecting
through a Unix-socket domain, the parameters have no effect.

Author: Ryohei Nagaura
Reviewed-by: Fabien Coelho, Robert Haas, Kyotaro Horiguchi, Kirk
Jamison, Mikalai Keida, Takayuki Tsunakawa, Andrei Yahorau
Discussion: https://postgr.es/m/EDA4195584F5064680D8130B1CA91C45367328@G01JPEXMBYT04
2019-04-06 15:23:37 +09:00
Tom Lane 959d00e9db Use Append rather than MergeAppend for scanning ordered partitions.
If we need ordered output from a scan of a partitioned table, but
the ordering matches the partition ordering, then we don't need to
use a MergeAppend to combine the pre-ordered per-partition scan
results: a plain Append will produce the same results.  This
both saves useless comparison work inside the MergeAppend proper,
and allows us to start returning tuples after istarting up just
the first child node not all of them.

However, all is not peaches and cream, because if some of the
child nodes have high startup costs then there will be big
discontinuities in the tuples-returned-versus-elapsed-time curve.
The planner's cost model cannot handle that (yet, anyway).
If we model the Append's startup cost as being just the first
child's startup cost, we may drastically underestimate the cost
of fetching slightly more tuples than are available from the first
child.  Since we've had bad experiences with over-optimistic choices
of "fast start" plans for ORDER BY LIMIT queries, that seems scary.
As a klugy workaround, set the startup cost estimate for an ordered
Append to be the sum of its children's startup costs (as MergeAppend
would).  This doesn't really describe reality, but it's less likely
to cause a bad plan choice than an underestimated startup cost would.
In practice, the cases where we really care about this optimization
will have child plans that are IndexScans with zero startup cost,
so that the overly conservative estimate is still just zero.

David Rowley, reviewed by Julien Rouhaud and Antonin Houska

Discussion: https://postgr.es/m/CAKJS1f-hAqhPLRk_RaSFTgYxd=Tz5hA7kQ2h4-DhJufQk8TGuw@mail.gmail.com
2019-04-05 19:20:43 -04:00
Alvaro Herrera 9f06d79ef8 Add facility to copy replication slots
This allows the user to create duplicates of existing replication slots,
either logical or physical, and even changing properties such as whether
they are temporary or the output plugin used.

There are multiple uses for this, such as initializing multiple replicas
using the slot for one base backup; when doing investigation of logical
replication issues; and to select a different output plugins.

Author: Masahiko Sawada
Reviewed-by: Michael Paquier, Andres Freund, Petr Jelinek
Discussion: https://postgr.es/m/CAD21AoAm7XX8y_tOPP6j4Nzzch12FvA1wPqiO690RCk+uYVstg@mail.gmail.com
2019-04-05 18:05:18 -03:00
Noah Misch 82150a05be Revert "Consistently test for in-use shared memory."
This reverts commits 2f932f71d9,
16ee6eaf80 and
6f0e190056.  The buildfarm has revealed
several bugs.  Back-patch like the original commits.

Discussion: https://postgr.es/m/20190404145319.GA1720877@rfd.leadboat.com
2019-04-05 00:00:52 -07:00
Andres Freund ea97e440b8 Harden tableam against nonexistant / wrong kind of AMs.
Previously it was allowed to set default_table_access_method to an
empty string. That makes sense for default_tablespace, where that was
copied from, as it signals falling back to the database's default
tablespace. As there is no equivalent for table AMs, forbid that.

Also make sure to throw a usable error when creating a table using an
index AM, by using get_am_type_oid() to implement get_table_am_oid()
instead of a separate copy. Previously we'd error out only later, in
GetTableAmRoutine().

Thirdly remove GetTableAmRoutineByAmId() - it was only used in an
earlier version of 8586bf7ed8.

Add tests for the above (some for index AMs as well).
2019-04-04 17:39:39 -07:00
Andres Freund 86b85044e8 tableam: Add table_multi_insert() and revamp/speed-up COPY FROM buffering.
This adds table_multi_insert(), and converts COPY FROM, the only user
of heap_multi_insert, to it.

A simple conversion of COPY FROM use slots would have yielded a
slowdown when inserting into a partitioned table for some
workloads. Different partitions might need different slots (both slot
types and their descriptors), and dropping / creating slots when
there's constant partition changes is measurable.

Thus instead revamp the COPY FROM buffering for partitioned tables to
allow to buffer inserts into multiple tables, flushing only when
limits are reached across all partition buffers. By only dropping
slots when there've been inserts into too many different partitions,
the aforementioned overhead is gone. By allowing larger batches, even
when there are frequent partition changes, we actuall speed such cases
up significantly.

By using slots COPY of very narrow rows into unlogged / temporary
might slow down very slightly (due to the indirect function calls).

Author: David Rowley, Andres Freund, Haribabu Kommi
Discussion:
    https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
    https://postgr.es/m/20190327054923.t3epfuewxfqdt22e@alap3.anarazel.de
2019-04-04 16:28:18 -07:00
Robert Haas a96c41feec Allow VACUUM to be run with index cleanup disabled.
This commit adds a new reloption, vacuum_index_cleanup, which
controls whether index cleanup is performed for a particular
relation by default.  It also adds a new option to the VACUUM
command, INDEX_CLEANUP, which can be used to override the
reloption.  If neither the reloption nor the VACUUM option is
used, the default is true, as before.

Masahiko Sawada, reviewed and tested by Nathan Bossart, Alvaro
Herrera, Kyotaro Horiguchi, Darafei Praliaskouski, and me.
The wording of the documentation is mostly due to me.

Discussion: http://postgr.es/m/CAD21AoAt5R3DNUZSjOoXDUY=naYPUOuffVsRzuTYMz29yLzQCA@mail.gmail.com
2019-04-04 15:04:43 -04:00
Stephen Frost 87e16db5eb Move the be_gssapi_get_* prototypes
The be_gssapi_get_* prototypes were put close to similar ones for SSL-
but a bit too close since that meant they ended up only being included
for SSL-enabled builds.  Move those to be under ENABLE_GSS instead.

Pointed out by Tom.
2019-04-04 11:11:46 -04:00
Thomas Munro 3eb77eba5a Refactor the fsync queue for wider use.
Previously, md.c and checkpointer.c were tightly integrated so that
fsync calls could be handed off and processed in the background.
Introduce a system of callbacks and file tags, so that other modules
can hand off fsync work in the same way.

For now only md.c uses the new interface, but other users are being
proposed.  Since there may be use cases that are not strictly SMGR
implementations, use a new function table for sync handlers rather
than extending the traditional SMGR one.

Instead of using a bitmapset of segment numbers for each RelFileNode
in the checkpointer's hash table, make the segment number part of the
key.  This requires sending explicit "forget" requests for every
segment individually when relations are dropped, but suits the file
layout schemes of proposed future users better (ie sparse or high
segment numbers).

Author: Shawn Debnath and Thomas Munro
Reviewed-by: Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/CAEepm=2gTANm=e3ARnJT=n0h8hf88wqmaZxk0JYkxw+b21fNrw@mail.gmail.com
2019-04-04 23:38:38 +13:00
Andres Freund b73c3a1196 tableam: basic documentation.
This adds documentation about the user oriented parts of table access
methods (i.e. the default_table_access_method GUC and the USING clause
for CREATE TABLE etc), adds a basic chapter about the table access
method interface, and adds a note to storage.sgml that it's contents
don't necessarily apply for non-builtin AMs.

Author: Haribabu Kommi and Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-04-03 17:40:29 -07:00
Noah Misch 2f932f71d9 Consistently test for in-use shared memory.
postmaster startup scrutinizes any shared memory segment recorded in
postmaster.pid, exiting if that segment matches the current data
directory and has an attached process.  When the postmaster.pid file was
missing, a starting postmaster used weaker checks.  Change to use the
same checks in both scenarios.  This increases the chance of a startup
failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1
postmaster.pid` && rm postmaster.pid && pg_ctl -w start".  A postmaster
will no longer recycle segments pertaining to other data directories.
That's good for production, but it's bad for integration tests that
crash a postmaster and immediately delete its data directory.  Such a
test now leaks a segment indefinitely.  No "make check-world" test does
that.  win32_shmem.c already avoided all these problems.  In 9.6 and
later, enhance PostgresNode to facilitate testing.  Back-patch to 9.4
(all supported versions).

Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.

Discussion: https://postgr.es/m/20130911033341.GD225735@tornado.leadboat.com
2019-04-03 17:03:46 -07:00
Tomas Vondra ea569d64ac Add SETTINGS option to EXPLAIN, to print modified settings.
Query planning is affected by a number of configuration options, and it
may be crucial to know which of those options were set to non-default
values.  With this patch you can say EXPLAIN (SETTINGS ON) to include
that information in the query plan.  Only options affecting planning,
with values different from the built-in default are printed.

This patch also adds auto_explain.log_settings option, providing the
same capability in auto_explain module.

Author: Tomas Vondra
Reviewed-by: Rafia Sabih, John Naylor
Discussion: https://postgr.es/m/e1791b4c-df9c-be02-edc5-7c8874944be0@2ndquadrant.com
2019-04-04 00:04:31 +02:00
Alvaro Herrera 799e220346 Log all statements from a sample of transactions
This is useful to obtain a view of the different transaction types in an
application, regardless of the durations of the statements each runs.

Author: Adrien Nayrat
Reviewed-by: Masahiko Sawada, Hayato Kuroda, Andres Freund
2019-04-03 18:43:59 -03:00
Tomas Vondra c50b3158bf Reduce overhead of pg_mcv_list (de)serialization
Commit ea4e1c0e8f resolved issues with memory alignment in serialized
pg_mcv_list values, but it required copying data to/from the varlena
buffer during serialization and deserialization.  As the MCV lits may
be fairly large, the overhead (memory consumption, CPU usage) can get
rather significant too.

This change tweaks the serialization format so that the alignment is
correct with respect to the varlena value, and so the parts may be
accessed directly without copying the data.

Catversion bump, as it affects existing pg_statistic_ext data.
2019-04-03 21:23:40 +02:00
Stephen Frost b0b39f72b9 GSSAPI encryption support
On both the frontend and backend, prepare for GSSAPI encryption
support by moving common code for error handling into a separate file.
Fix a TODO for handling multiple status messages in the process.
Eliminate the OIDs, which have not been needed for some time.

Add frontend and backend encryption support functions.  Keep the
context initiation for authentication-only separate on both the
frontend and backend in order to avoid concerns about changing the
requested flags to include encryption support.

In postmaster, pull GSSAPI authorization checking into a shared
function.  Also share the initiator name between the encryption and
non-encryption codepaths.

For HBA, add "hostgssenc" and "hostnogssenc" entries that behave
similarly to their SSL counterparts.  "hostgssenc" requires either
"gss", "trust", or "reject" for its authentication.

Similarly, add a "gssencmode" parameter to libpq.  Supported values are
"disable", "require", and "prefer".  Notably, negotiation will only be
attempted if credentials can be acquired.  Move credential acquisition
into its own function to support this behavior.

Add a simple pg_stat_gssapi view similar to pg_stat_ssl, for monitoring
if GSSAPI authentication was used, what principal was used, and if
encryption is being used on the connection.

Finally, add documentation for everything new, and update existing
documentation on connection security.

Thanks to Michael Paquier for the Windows fixes.

Author: Robbie Harwood, with changes to the read/write functions by me.
Reviewed in various forms and at different times by: Michael Paquier,
   Andres Freund, David Steele.
Discussion: https://www.postgresql.org/message-id/flat/jlg1tgq1ktm.fsf@thriss.redhat.com
2019-04-03 15:02:33 -04:00
Alvaro Herrera f56f8f8da6 Support foreign keys that reference partitioned tables
Previously, while primary keys could be made on partitioned tables, it
was not possible to define foreign keys that reference those primary
keys.  Now it is possible to do that.

Author: Álvaro Herrera
Reviewed-by: Amit Langote, Jesper Pedersen
Discussion: https://postgr.es/m/20181102234158.735b3fevta63msbj@alvherre.pgsql
2019-04-03 14:40:21 -03:00
Heikki Linnakangas 9155580fd5 Generate less WAL during GiST, GIN and SP-GiST index build.
Instead of WAL-logging every modification during the build separately,
first build the index without any WAL-logging, and make a separate pass
through the index at the end, to write all pages to the WAL. This
significantly reduces the amount of WAL generated, and is usually also
faster, despite the extra I/O needed for the extra scan through the index.
WAL generated this way is also faster to replay.

For GiST, the LSN-NSN interlock makes this a little tricky. All pages must
be marked with a valid (i.e. non-zero) LSN, so that the parent-child
LSN-NSN interlock works correctly. We now use magic value 1 for that during
index build. Change the fake LSN counter to begin from 1000, so that 1 is
safely smaller than any real or fake LSN. 2 would've been enough for our
purposes, but let's reserve a bigger range, in case we need more special
values in the future.

Author: Anastasia Lubennikova, Andrey V. Lepikhov
Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
2019-04-03 17:03:15 +03:00
Alvaro Herrera ab0dfc961b Report progress of CREATE INDEX operations
This uses the progress reporting infrastructure added by c16dc1aca5,
adding support for CREATE INDEX and CREATE INDEX CONCURRENTLY.

There are two pieces to this: one is index-AM-agnostic, and the other is
AM-specific.  The latter is fairly elaborate for btrees, including
reportage for parallel index builds and the separate phases that btree
index creation uses; other index AMs, which are much simpler in their
building procedures, have simplistic reporting only, but that seems
sufficient, at least for non-concurrent builds.

The index-AM-agnostic part is fairly complete, providing insight into
the CONCURRENTLY wait phases as well as block-based progress during the
index validation table scan.  (The index validation index scan requires
patching each AM, which has not been included here.)

Reviewers: Rahila Syed, Pavan Deolasee, Tatsuro Yamada
Discussion: https://postgr.es/m/20181220220022.mg63bhk26zdpvmcj@alvherre.pgsql
2019-04-02 15:18:08 -03:00
Stephen Frost 4d0e994eed Add support for partial TOAST decompression
When asked for a slice of a TOAST entry, decompress enough to return the
slice instead of decompressing the entire object.

For use cases where the slice is at, or near, the beginning of the entry,
this avoids a lot of unnecessary decompression work.

This changes the signature of pglz_decompress() by adding a boolean to
indicate if it's ok for the call to finish before consuming all of the
source or destination buffers.

Author: Paul Ramsey
Reviewed-By: Rafia Sabih, Darafei Praliaskouski, Regina Obe
Discussion: https://postgr.es/m/CACowWR07EDm7Y4m2kbhN_jnys%3DBBf9A6768RyQdKm_%3DNpkcaWg%40mail.gmail.com
2019-04-02 12:35:32 -04:00
Etsuro Fujita d50d172e51 postgres_fdw: Perform the (FINAL, NULL) upperrel operations remotely.
The upper-planner pathification allows FDWs to arrange to push down
different types of upper-stage operations to the remote side.  This
commit teaches postgres_fdw to do it for the (FINAL, NULL) upperrel,
which is responsible for doing LockRows, LIMIT, and/or ModifyTable.
This provides the ability for postgres_fdw to handle SELECT commands
so that it 1) skips the LockRows step (if any) (note that this is
safe since it performs early locking) and 2) pushes down the LIMIT
and/or OFFSET restrictions (if any) to the remote side.  This doesn't
handle the INSERT/UPDATE/DELETE cases.

Author: Etsuro Fujita
Reviewed-By: Antonin Houska and Jeff Janes
Discussion: https://postgr.es/m/87pnz1aby9.fsf@news-spur.riddles.org.uk
2019-04-02 20:30:45 +09:00
Etsuro Fujita aef65db676 Refactor create_limit_path() to share cost adjustment code with FDWs.
This is in preparation for an upcoming commit.

Author: Etsuro Fujita
Reviewed-By: Antonin Houska and Jeff Janes
Discussion: https://postgr.es/m/87pnz1aby9.fsf@news-spur.riddles.org.uk
2019-04-02 19:55:12 +09:00
Thomas Munro 475861b261 Add wal_recycle and wal_init_zero GUCs.
On at least ZFS, it can be beneficial to create new WAL files every
time and not to bother zero-filling them.  Since it's not clear which
other filesystems might benefit from one or both of those things,
add individual GUCs to control those two behaviors independently and
make only very general statements in the docs.

Author: Jerry Jelinek, with some adjustments by Thomas Munro
Reviewed-by: Alvaro Herrera, Andres Freund, Tomas Vondra, Robert Haas and others
Discussion: https://postgr.es/m/CACPQ5Fo00QR7LNAcd1ZjgoBi4y97%2BK760YABs0vQHH5dLdkkMA%40mail.gmail.com
2019-04-02 14:37:14 +13:00
Andres Freund d45e401586 tableam: Add table_finish_bulk_insert().
This replaces the previous calls of heap_sync() in places using
bulk-insert. By passing in the flags used for bulk-insert the AM can
decide (first at insert time and then during the finish call) which of
the optimizations apply to it, and what operations are necessary to
finish a bulk insert operation.

Also change HEAP_INSERT_* flags to TABLE_INSERT, and rename hi_options
to ti_options.

These changes are made even in copy.c, which hasn't yet been converted
to tableam. There's no harm in doing so.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-04-01 14:41:42 -07:00
Peter Eisentraut cc8d415117 Unified logging system for command-line programs
This unifies the various ad hoc logging (message printing, error
printing) systems used throughout the command-line programs.

Features:

- Program name is automatically prefixed.

- Message string does not end with newline.  This removes a common
  source of inconsistencies and omissions.

- Additionally, a final newline is automatically stripped, simplifying
  use of PQerrorMessage() etc., another common source of mistakes.

- I converted error message strings to use %m where possible.

- As a result of the above several points, more translatable message
  strings can be shared between different components and between
  frontends and backend, without gratuitous punctuation or whitespace
  differences.

- There is support for setting a "log level".  This is not meant to be
  user-facing, but can be used internally to implement debug or
  verbose modes.

- Lazy argument evaluation, so no significant overhead if logging at
  some level is disabled.

- Some color in the messages, similar to gcc and clang.  Set
  PG_COLOR=auto to try it out.  Some colors are predefined, but can be
  customized by setting PG_COLORS.

- Common files (common/, fe_utils/, etc.) can handle logging much more
  simply by just using one API without worrying too much about the
  context of the calling program, requiring callbacks, or having to
  pass "progname" around everywhere.

- Some programs called setvbuf() to make sure that stderr is
  unbuffered, even on Windows.  But not all programs did that.  This
  is now done centrally.

Soft goals:

- Reduces vertical space use and visual complexity of error reporting
  in the source code.

- Encourages more deliberate classification of messages.  For example,
  in some cases it wasn't clear without analyzing the surrounding code
  whether a message was meant as an error or just an info.

- Concepts and terms are vaguely aligned with popular logging
  frameworks such as log4j and Python logging.

This is all just about printing stuff out.  Nothing affects program
flow (e.g., fatal exits).  The uses are just too varied to do that.
Some existing code had wrappers that do some kind of print-and-exit,
and I adapted those.

I tried to keep the output mostly the same, but there is a lot of
historical baggage to unwind and special cases to consider, and I
might not always have succeeded.  One significant change is that
pg_rewind used to write all error messages to stdout.  That is now
changed to stderr.

Reviewed-by: Donald Dong <xdong@csumb.edu>
Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru>
Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 20:01:35 +02:00
Alexander Korotkov 0a02e2ae02 GIN support for @@ and @? jsonpath operators
This commit makes existing GIN operator classes jsonb_ops and json_path_ops
support "jsonb @@ jsonpath" and "jsonb @? jsonpath" operators.  Basic idea is
to extract statements of following form out of jsonpath.

 key1.key2. ... .keyN = const

The rest of jsonpath is rechecked from heap.

Catversion is bumped.

Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Author: Nikita Glukhov, Alexander Korotkov
Reviewed-by: Jonathan Katz, Pavel Stehule
2019-04-01 18:08:52 +03:00