Commit Graph

1849 Commits

Author SHA1 Message Date
Andres Freund c03c1449c0 Fix issues around EXPLAIN with JIT.
I (Andres) was more than a bit hasty in committing 33001fd7a7
after last minute changes, leading to a number of problems (jit output
was only shown for JIT in parallel workers, and just EXPLAIN without
ANALYZE didn't work).  Lukas luckily found these issues quickly.

Instead of combining instrumentation in in standard_ExecutorEnd(), do
so on demand in the new ExplainPrintJITSummary().

Also update a documentation example of the JIT output, changed in
52050ad8eb.

Author: Lukas Fittl, with minor changes by me
Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com
Backpatch: 11, where JIT compilation was introduced
2018-10-03 12:48:37 -07:00
Tom Lane 6e35939feb Change rewriter/planner/executor/plancache to depend on RTE rellockmode.
Instead of recomputing the required lock levels in all these places,
just use what commit fdba460a2 made the parser store in the RTE fields.
This already simplifies the code measurably in these places, and
follow-on changes will remove a bunch of no-longer-needed infrastructure.

In a few cases, this change causes us to acquire a higher lock level
than we did before.  This is OK primarily because said higher lock level
should've been acquired already at query parse time; thus, we're saving
a useless extra trip through the shared lock manager to acquire a lesser
lock alongside the original lock.  The only known exception to this is
that re-execution of a previously planned SELECT FOR UPDATE/SHARE query,
for a table that uses ROW_MARK_REFERENCE or ROW_MARK_COPY methods, might
have gotten only AccessShareLock before.  Now it will get RowShareLock
like the first execution did, which seems fine.

While there's more to do, push it in this state anyway, to let the
buildfarm help verify that nothing bad happened.

Amit Langote, reviewed by David Rowley and Jesper Pedersen,
and whacked around a bit more by me

Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
2018-10-02 14:43:09 -04:00
Andres Freund cc2905e963 Use slots more widely in tuple mapping code and make naming more consistent.
It's inefficient to use a single slot for mapping between tuple
descriptors for multiple tuples, as previously done when using
ConvertPartitionTupleSlot(), as that means the slot's tuple descriptors
change for every tuple.

Previously we also, via ConvertPartitionTupleSlot(), built new tuples
after the mapping even in cases where we, immediately afterwards,
access individual columns again.

Refactor the code so one slot, on demand, is used for each
partition. That avoids having to change the descriptor (and allows to
use the more efficient "fixed" tuple slots). Then use slot->slot
mapping, to avoid unnecessarily forming a tuple.

As the naming between the tuple and slot mapping functions wasn't
consistent, rename them to execute_attr_map_{tuple,slot}.  It's likely
that we'll also rename convert_tuples_by_* to denote that these
functions "only" build a map, but that's left for later.

Author: Amit Khandekar and Amit Langote, editorialized by me
Reviewed-By: Amit Langote, Amit Khandekar, Andres Freund
Discussion:
    https://postgr.es/m/CAJ3gD9fR0wRNeAE8VqffNTyONS_UfFPRpqxhnD9Q42vZB+Jvpg@mail.gmail.com
    https://postgr.es/m/e4f9d743-cd4b-efb0-7574-da21d86a7f36%40lab.ntt.co.jp
Backpatch: -
2018-10-02 11:14:26 -07:00
Tom Lane fdba460a26 Create an RTE field to record the query's lock mode for each relation.
Add RangeTblEntry.rellockmode, which records the appropriate lock mode for
each RTE_RELATION rangetable entry (either AccessShareLock, RowShareLock,
or RowExclusiveLock depending on the RTE's role in the query).

This patch creates the field and makes all creators of RTE nodes fill it
in reasonably, but for the moment nothing much is done with it.  The plan
is to replace assorted post-parser logic that re-determines the right
lockmode to use with simple uses of rte->rellockmode.  For now, just add
Asserts in each of those places that the rellockmode matches what they are
computing today.  (In some cases the match isn't perfect, so the Asserts
are weaker than you might expect; but this seems OK, as per discussion.)

This passes check-world for me, but it seems worth pushing in this state
to see if the buildfarm finds any problems in cases I failed to test.

catversion bump due to change of stored rules.

Amit Langote, reviewed by David Rowley and Jesper Pedersen,
and whacked around a bit more by me

Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
2018-09-30 13:55:51 -04:00
Andres Freund 10763358c3 Remove absolete function TupleDescGetSlot().
TupleDescGetSlot() was kept around for backward compatibility for
user-written SRFs. With the TupleTableSlot abstraction work, that code
will need to be version specific anyway, so there's no point in
keeping the function around any longer.

Author: Ashutosh Bapat
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
2018-09-25 16:28:57 -07:00
Andres Freund 29c94e03c7 Split ExecStoreTuple into ExecStoreHeapTuple and ExecStoreBufferHeapTuple.
Upcoming changes introduce further types of tuple table slots, in
preparation of making table storage pluggable. New storage methods
will have different representation of tuples, therefore the slot
accessor should refer explicitly to heap tuples.

Instead of just renaming the functions, split it into one function
that accepts heap tuples not residing in buffers, and one accepting
ones in buffers.  Previously one function was used for both, but that
was a bit awkward already, and splitting will allow us to represent
slot types for tuples in buffers and normal memory separately.

This is split out from the patch introducing abstract slots, as this
largely consists out of mechanical changes.

Author: Ashutosh Bapat
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
2018-09-25 16:27:48 -07:00
Andres Freund bbdfbb9154 Remove function list from prologue of execTuples.c.
That section is never in sync with the actual routines available and
their functionality.

Author: Ashutosh Bapat
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
2018-09-25 16:27:48 -07:00
Alvaro Herrera 5913b9bbf3 Remove obsolete comment
The documented shortcoming was actually fixed in 4c728f3829
so the comment is not true anymore.
2018-09-25 17:55:22 -03:00
Andres Freund 33001fd7a7 Collect JIT instrumentation from workers.
Previously, when using parallel query, EXPLAIN (ANALYZE)'s JIT
compilation timings did not include the overhead from doing so on the
workers.  Fix that.

We do so by simply aggregating the cost of doing JIT compilation on
workers and the leader together. Arguably that's not quite accurate,
because the total time spend doing so is spent in parallel - but it's
hard to do much better.  For additional detail, when VERBOSE is
specified, the stats for workers are displayed separately.

Author: Amit Khandekar and Andres Freund
Discussion: https://postgr.es/m/CAJ3gD9eLrz51RK_gTkod+71iDcjpB_N8eC6vU2AW-VicsAERpQ@mail.gmail.com
Backpatch: 11-
2018-09-25 13:12:44 -07:00
Tom Lane 89b280e139 Fix failure in WHERE CURRENT OF after rewinding the referenced cursor.
In a case where we have multiple relation-scan nodes in a cursor plan,
such as a scan of an inheritance tree, it's possible to fetch from a
given scan node, then rewind the cursor and fetch some row from an
earlier scan node.  In such a case, execCurrent.c mistakenly thought
that the later scan node was still active, because ExecReScan hadn't
done anything to make it look not-active.  We'd get some sort of
failure in the case of a SeqScan node, because the node's scan tuple
slot would be pointing at a HeapTuple whose t_self gets reset to
invalid by heapam.c.  But it seems possible that for other relation
scan node types we'd actually return a valid tuple TID to the caller,
resulting in updating or deleting a tuple that shouldn't have been
considered current.  To fix, forcibly clear the ScanTupleSlot in
ExecScanReScan.

Another issue here, which seems only latent at the moment but could
easily become a live bug in future, is that rewinding a cursor does
not necessarily lead to *immediately* applying ExecReScan to every
scan-level node in the plan tree.  Upper-level nodes will think that
they can postpone that call if their child node is already marked
with chgParam flags.  I don't see a way for that to happen today in
a plan tree that's simple enough for execCurrent.c's search_plan_tree
to understand, but that's one heck of a fragile assumption.  So, add
some logic in search_plan_tree to detect chgParam flags being set on
nodes that it descended to/through, and assume that that means we
should consider lower scan nodes to be logically reset even if their
ReScan call hasn't actually happened yet.

Per bug #15395 from Matvey Arye.  This has been broken for a long time,
so back-patch to all supported branches.

Discussion: https://postgr.es/m/153764171023.14986.280404050547008575@wrigleys.postgresql.org
2018-09-23 16:05:45 -04:00
Tom Lane 07a3af0ff8 Fix parsetree representation of XMLTABLE(XMLNAMESPACES(DEFAULT ...)).
The original coding for XMLTABLE thought it could represent a default
namespace by a T_String Value node with a null string pointer.  That's
not okay, though; in particular outfuncs.c/readfuncs.c are not on board
with such a representation, meaning you'll get a null pointer crash
if you try to store a view or rule containing this construct.

To fix, change the parsetree representation so that we have a NULL
list element, instead of a bogus Value node.

This isn't really a functional limitation since default XML namespaces
aren't yet implemented in the executor; you'd just get "DEFAULT
namespace is not supported" anyway.  But crashes are not nice, so
back-patch to v10 where this syntax was added.  Ordinarily we'd consider
a parsetree representation change to be un-backpatchable; but since
existing releases would crash on the way to storing such constructs,
there can't be any existing views/rules to be incompatible with.

Per report from Andrey Lepikhov.

Discussion: https://postgr.es/m/3690074f-abd2-56a9-144a-aa5545d7a291@postgrespro.ru
2018-09-17 13:16:32 -04:00
Tom Lane 1f4a920b73 Fix failure with initplans used conditionally during EvalPlanQual rechecks.
The EvalPlanQual machinery assumes that any initplans (that is,
uncorrelated sub-selects) used during an EPQ recheck would have already
been evaluated during the main query; this is implicit in the fact that
execPlan pointers are not copied into the EPQ estate's es_param_exec_vals.
But it's possible for that assumption to fail, if the initplan is only
reached conditionally.  For example, a sub-select inside a CASE expression
could be reached during a recheck when it had not been previously, if the
CASE test depends on a column that was just updated.

This bug is old, appearing to date back to my rewrite of EvalPlanQual in
commit 9f2ee8f28, but was not detected until Kyle Samson reported a case.

To fix, force all not-yet-evaluated initplans used within the EPQ plan
subtree to be evaluated at the start of the recheck, before entering the
EPQ environment.  This could be inefficient, if such an initplan is
expensive and goes unused again during the recheck --- but that's piling
one layer of improbability atop another.  It doesn't seem worth adding
more complexity to prevent that, at least not in the back branches.

It was convenient to use the new-in-v11 ExecEvalParamExecParams function
to implement this, but I didn't like either its name or the specifics of
its API, so revise that.

Back-patch all the way.  Rather than rewrite the patch to avoid depending
on bms_next_member() in the oldest branches, I chose to back-patch that
function into 9.4 and 9.3.  (This isn't the first time back-patches have
needed that, and it exhausted my patience.)  I also chose to back-patch
some test cases added by commits 71404af2a and 342a1ffa2 into 9.4 and 9.3,
so that the 9.x versions of eval-plan-qual.spec are all the same.

Andrew Gierth diagnosed the problem and contributed the added test cases,
though the actual code changes are by me.

Discussion: https://postgr.es/m/A033A40A-B234-4324-BE37-272279F7B627@tripadvisor.com
2018-09-15 13:42:33 -04:00
Alvaro Herrera 6b78231d91 Move PartitionDispatchData struct definition to execPartition.c
There's no reason to expose the struct definition, so don't.

Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Discussion: https://postgr.es/m/d3fa24c1-bc65-7133-81df-6474387ccc4f@lab.ntt.co.jp
2018-09-14 19:06:57 -03:00
Tom Lane 361844fe56 Save/restore SPI's global variables in SPI_connect() and SPI_finish().
This patch removes two sources of interference between nominally
independent functions when one SPI-using function calls another,
perhaps without knowing that it does so.

Chapman Flack pointed out that xml.c's query_to_xml_internal() expects
SPI_tuptable and SPI_processed to stay valid across datatype output
function calls; but it's possible that such a call could involve
re-entrant use of SPI.  It seems likely that there are similar hazards
elsewhere, if not in the core code then in third-party SPI users.
Previously SPI_finish() reset SPI's API globals to zeroes/nulls, which
would typically make for a crash in such a situation.  Restoring them
to the values they had at SPI_connect() seems like a considerably more
useful behavior, and it still meets the design goal of not leaving any
dangling pointers to tuple tables of the function being exited.

Also, cause SPI_connect() to reset these variables to zeroes/nulls after
saving them.  This prevents interference in the opposite direction: it's
possible that a SPI-using function that's only ever been tested standalone
contains assumptions that these variables start out as zeroes.  That was
the case as long as you were the outermost SPI user, but not so much for
an inner user.  Now it's consistent.

Report and fix suggestion by Chapman Flack, actual patch by me.
Back-patch to all supported branches.

Discussion: https://postgr.es/m/9fa25bef-2e4f-1c32-22a4-3ad0723c4a17@anastigmatix.net
2018-09-07 20:09:57 -04:00
Andrew Gierth 520acab171 Set scan direction appropriately for SubPlans (bug #15336)
When executing a SubPlan in an expression, the EState's direction
field was left alone, resulting in an attempt to execute the subplan
backwards if it was encountered during a backwards scan of a cursor.
Also, though much less likely, it was possible to reach the execution
of an InitPlan while in backwards-scan state.

Repair by saving/restoring estate->es_direction and forcing forward
scan mode in the relevant places.

Backpatch all the way, since this has been broken since 8.3 (prior to
commit c7ff7663e, SubPlans had their own EStates rather than sharing
the parent plan's, so there was no confusion over scan direction).

Per bug #15336 reported by Vladimir Baranoff; analysis and patch by
me, review by Tom Lane.

Discussion: https://postgr.es/m/153449812167.1304.1741624125628126322@wrigleys.postgresql.org
2018-08-17 15:44:13 +01:00
Alvaro Herrera 1eb9221585 Fix executor prune failure when plan already pruned
In a multi-layer partitioning setup, if at plan time all the
sub-partitions are pruned but the intermediate one remains, the executor
later throws a spurious error that there's nothing to prune.  That is
correct, but there's no reason to throw an error.  Therefore, don't.

Reported-by: Andreas Seltenreich <seltenreich@gmx.de>
Author: David Rowley <david.rowley@2ndquadrant.com>
Discussion: https://postgr.es/m/87in4h98i0.fsf@ansel.ydns.eu
2018-08-16 12:53:43 -03:00
Amit Kapila 4f9a97e417 Adjust comment atop ExecShutdownNode.
After commits a315b967cc and b805b63ac2, part of the comment atop
ExecShutdownNode is redundant.  Adjust it.

Author: Amit Kapila
Backpatch-through: 10 where both the mentioned commits are present.
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
2018-08-13 10:04:39 +05:30
Amit Kapila 2cd0acfdad Prohibit shutting down resources if there is a possibility of back up.
Currently, we release the asynchronous resources as soon as it is evident
that no more rows will be needed e.g. when a Limit is filled.  This can be
problematic especially for custom and foreign scans where we can scan
backward.  Fix that by disallowing the shutting down of resources in such
cases.

Reported-by: Robert Haas
Analysed-by: Robert Haas and Amit Kapila
Author: Amit Kapila
Reviewed-by: Robert Haas
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
2018-08-13 08:22:18 +05:30
Andrew Gierth 07172d5aff Avoid query-lifetime memory leaks in XMLTABLE (bug #15321)
Multiple calls to XMLTABLE in a query (e.g. laterally applying it to a
table with an xml column, an important use-case) were leaking large
amounts of memory into the per-query context, blowing up memory usage.

Repair by reorganizing memory context usage in nodeTableFuncscan; use
the usual per-tuple context for row-by-row evaluations instead of
perValueCxt, and use the explicitly created context -- renamed from
perValueCxt to perTableCxt -- for arguments and state for each
individual table-generation operation.

Backpatch to PG10 where this code was introduced.

Original report by IRC user begriffs; analysis and patch by me.
Reviewed by Tom Lane and Pavel Stehule.

Discussion: https://postgr.es/m/153394403528.10284.7530399040974170549@wrigleys.postgresql.org
2018-08-13 01:59:45 +01:00
Andrew Dunstan 5c047fd709 Revert changes in execMain.c from commit 16828d5c02
These changes were put in at some stage of the development process, but
are unnecessary and should not have made it into the final patch. Mea
culpa.

Per gripe from Andreas Freund

Backpatch to REL_11_STABLE
2018-08-10 16:09:25 -04:00
Amit Kapila 85c9d3475e Fix buffer usage stats for parallel nodes.
The buffer usage stats is accounted only for the execution phase of the
node.  For Gather and Gather Merge nodes, such stats are accumulated at
the time of shutdown of workers which is done after execution of node due
to which we missed to account them for such nodes.  Fix it by treating
nodes as running while we shut down them.

We can also miss accounting for a Limit node when Gather or Gather Merge
is beneath it, because it can finish the execution before shutting down
such nodes.  So we allow a Limit node to shut down the resources before it
completes the execution.

In the passing fix the gather node code to allow workers to shut down as
soon as we find that all the tuples from the workers have been retrieved.
The original code use to do that, but is accidently removed by commit
01edb5c7fc.

Reported-by: Adrien Nayrat
Author: Amit Kapila and Robert Haas
Reviewed-by: Robert Haas and Andres Freund
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
2018-08-03 11:02:02 +05:30
Amit Kapila ccc84a956b Match the buffer usage tracking for leader and worker backends.
In the leader backend, we don't track the buffer usage for ExecutorStart
phase whereas in worker backend we track it for ExecutorStart phase as
well.  This leads to different value for buffer usage stats for the
parallel and non-parallel query.  Change the code so that worker backend
also starts tracking buffer usage after ExecutorStart.

Author: Amit Kapila and Robert Haas
Reviewed-by: Robert Haas and Andres Freund
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
2018-08-03 09:11:37 +05:30
Tom Lane 1c2cb2744b Fix run-time partition pruning for appends with multiple source rels.
The previous coding here supposed that if run-time partitioning applied to
a particular Append/MergeAppend plan, then all child plans of that node
must be members of a single partitioning hierarchy.  This is totally wrong,
since an Append could be formed from a UNION ALL: we could have multiple
hierarchies sharing the same Append, or child plans that aren't part of any
hierarchy.

To fix, restructure the related plan-time and execution-time data
structures so that we can have a separate list or array for each
partitioning hierarchy.  Also track subplans that are not part of any
hierarchy, and make sure they don't get pruned.

Per reports from Phil Florent and others.  Back-patch to v11, since
the bug originated there.

David Rowley, with a lot of cosmetic adjustments by me; thanks also
to Amit Langote for review.

Discussion: https://postgr.es/m/HE1PR03MB17068BB27404C90B5B788BCABA7B0@HE1PR03MB1706.eurprd03.prod.outlook.com
2018-08-01 19:42:52 -04:00
Alvaro Herrera 91bc213d90 Fix unnoticed variable shadowing in previous commit
Per buildfarm.
2018-08-01 17:04:57 -04:00
Alvaro Herrera 1c9bb02d8e Fix per-tuple memory leak in partition tuple routing
Some operations were being done in a longer-lived memory context,
causing intra-query leaks.  It's not noticeable unless you're doing a
large COPY, but if you are, it eats enough memory to cause a problem.

Co-authored-by: Kohei KaiGai <kaigai@heterodb.com>
Co-authored-by: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAOP8fzYtVFWZADq4c=KoTAqgDrHWfng+AnEPEZccyxqxPVbbWQ@mail.gmail.com
2018-08-01 16:29:15 -04:00
Peter Eisentraut 0d5f05cde0 Allow multi-inserts during COPY into a partitioned table
CopyFrom allows multi-inserts to be used for non-partitioned tables, but
this was disabled for partitioned tables.  The reason for this appeared
to be that the tuple may not belong to the same partition as the
previous tuple did.  Not allowing multi-inserts here greatly slowed down
imports into partitioned tables.  These could take twice as long as a
copy to an equivalent non-partitioned table.  It seems wise to do
something about this, so this change allows the multi-inserts by
flushing the so-far inserted tuples to the partition when the next tuple
does not belong to the same partition, or when the buffer fills.  This
improves performance when the next tuple in the stream commonly belongs
to the same partition as the previous tuple.

In cases where the target partition changes on every tuple, using
multi-inserts slightly slows the performance.  To get around this we
track the average size of the batches that have been inserted and
adaptively enable or disable multi-inserts based on the size of the
batch.  Some testing was done and the regression only seems to exist
when the average size of the insert batch is close to 1, so let's just
enable multi-inserts when the average size is at least 1.3.  More
performance testing might reveal a better number for, this, but since
the slowdown was only 1-2% it does not seem critical enough to spend too
much time calculating it.  In any case it may depend on other factors
rather than just the size of the batch.

Allowing multi-inserts for partitions required a bit of work around the
per-tuple memory contexts as we must flush the tuples when the next
tuple does not belong the same partition.  In which case there is no
good time to reset the per-tuple context, as we've already built the new
tuple by this time.  In order to work around this we maintain two
per-tuple contexts and just switch between them every time the partition
changes and reset the old one.  This does mean that the first of each
batch of tuples is not allocated in the same memory context as the
others, but that does not matter since we only reset the context once
the previous batch has been inserted.

Author: David Rowley <david.rowley@2ndquadrant.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
2018-08-01 10:23:09 +02:00
Alvaro Herrera d25d45e4d9 Verify range bounds to bms_add_range when necessary
Now that the bms_add_range boundary protections are gone, some
alternative ones are needed in a few places.

Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Discussion: https://postgr.es/m/3437ccf8-a144-55ff-1e2f-fc16b437823b@lab.ntt.co.jp
2018-07-30 18:45:39 -04:00
Robert Haas 3e32109049 Use key and partdesc from PartitionDispatch where possible.
Instead of repeatedly fishing the data out of the relcache entry,
let's use the version that we cached in the PartitionDispatch.  We
could alternatively rip out the PartitionDispatch fields altogether,
but it doesn't make much sense to have them and not use them; before
this patch, partdesc was set but altogether unused.  Amit Langote and
I both thought using them was a litle better than removing them, so
this patch takes that approach.

Discussion: http://postgr.es/m/CA+TgmobFnxcaW-Co-XO8=yhJ5pJXoNkCj6Z7jm9Mwj9FGv-D7w@mail.gmail.com
2018-07-27 09:40:52 -04:00
Andres Freund 3acc4acd9b LLVMJIT: Release JIT context after running ExprContext shutdown callbacks.
Due to inlining it previously was possible that an ExprContext's
shutdown callback pointed to a JITed function. As the JIT context
previously was shut down before the shutdown callbacks were called,
that could lead to segfaults.  Fix the ordering.

Reported-By: Dmitry Dolgov
Author: Andres Freund
Discussion: https://postgr.es/m/CA+q6zcWO7CeAJtHBxgcHn_hj+PenM=tvG0RJ93X1uEJ86+76Ug@mail.gmail.com
Backpatch: 11-, where JIT compilation was added
2018-07-25 16:31:49 -07:00
Heikki Linnakangas 99fdebaf2d Rephrase a few comments for clarity.
I was confused by what "intended to be parallel serially" meant, until
Robert Haas and David G. Johnston explained it. Rephrase the comment to
make it more clear, using David's suggested wording.

Discussion: https://www.postgresql.org/message-id/1fec9022-41e8-e484-70ce-2179b08c2092%40iki.fi
2018-07-19 16:08:09 +03:00
Heikki Linnakangas 405cb356d6 Fix comment.
This comment was copy-pasted from nodeAppend.c to nodeMergeAppend.c, but
while committing 5220bb7533, I modified wrong copy of it.

Spotted by David Rowley
2018-07-19 15:39:06 +03:00
Heikki Linnakangas 5220bb7533 Expand run-time partition pruning to work with MergeAppend
This expands the support for the run-time partition pruning which was added
for Append in 499be013de to also allow unneeded subnodes of a MergeAppend
to be removed.

Author: David Rowley
Discussion: https://www.postgresql.org/message-id/CAKJS1f_F_V8D7Wu-HVdnH7zCUxhoGK8XhLLtd%3DCu85qDZzXrgg%40mail.gmail.com
2018-07-19 13:49:43 +03:00
Heikki Linnakangas 6b387179ba Fix misc typos, mostly in comments.
A collection of typos I happened to spot while reading code, as well as
grepping for common mistakes.

Backpatch to all supported versions, as applicable, to avoid conflicts
when backporting other commits in the future.
2018-07-18 16:17:32 +03:00
Amit Kapila 40ca70ebcc Allow using the updated tuple while moving it to a different partition.
An update that causes the tuple to be moved to a different partition was
missing out on re-constructing the to-be-updated tuple, based on the latest
tuple in the update chain.  Instead, it's simply deleting the latest tuple
and inserting a new tuple in the new partition based on the old tuple.
Commit 2f17844104 didn't consider this case, so some of the updates were
getting lost.

In passing, change the argument order for output parameter in ExecDelete
and add some commentary about it.

Reported-by: Pavan Deolasee
Author: Amit Khandekar, with minor changes by me
Reviewed-by: Dilip Kumar, Amit Kapila and Alvaro Herrera
Backpatch-through: 11
Discussion: https://postgr.es/m/CAJ3gD9fRbEzDqdeDq1jxqZUb47kJn+tQ7=Bcgjc8quqKsDViKQ@mail.gmail.com
2018-07-12 12:51:39 +05:30
Tom Lane ff4f889164 Fix bugs with degenerate window ORDER BY clauses in GROUPS/RANGE mode.
nodeWindowAgg.c failed to cope with the possibility that no ordering
columns are defined in the window frame for GROUPS mode or RANGE OFFSET
mode, leading to assertion failures or odd errors, as reported by Masahiko
Sawada and Lukas Eder.  In RANGE OFFSET mode, an ordering column is really
required, so add an Assert about that.  In GROUPS mode, the code would
work, except that the node initialization code wasn't in sync with the
execution code about when to set up tuplestore read pointers and spare
slots.  Fix the latter for consistency's sake (even though I think the
changes described below make the out-of-sync cases unreachable for now).

Per SQL spec, a single ordering column is required for RANGE OFFSET mode,
and at least one ordering column is required for GROUPS mode.  The parser
enforced the former but not the latter; add a check for that.

We were able to reach the no-ordering-column cases even with fully spec
compliant queries, though, because the planner would drop partitioning
and ordering columns from the generated plan if they were redundant with
earlier columns according to the redundant-pathkey logic, for instance
"PARTITION BY x ORDER BY y" in the presence of a "WHERE x=y" qual.
While in principle that's an optimization that could save some pointless
comparisons at runtime, it seems unlikely to be meaningful in the real
world.  I think this behavior was not so much an intentional optimization
as a side-effect of an ancient decision to construct the plan node's
ordering-column info by reverse-engineering the PathKeys of the input
path.  If we give up redundant-column removal then it takes very little
code to generate the plan node info directly from the WindowClause,
ensuring that we have the expected number of ordering columns in all
cases.  (If anyone does complain about this, the planner could perhaps
be taught to remove redundant columns only when it's safe to do so,
ie *not* in RANGE OFFSET mode.  But I doubt anyone ever will.)

With these changes, the WindowAggPath.winpathkeys field is not used for
anything anymore, so remove it.

The test cases added here are not actually very interesting given the
removal of the redundant-column-removal logic, but they would represent
important corner cases if anyone ever tries to put that back.

Tom Lane and Masahiko Sawada.  Back-patch to v11 where RANGE OFFSET
and GROUPS modes were added.

Discussion: https://postgr.es/m/CAD21AoDrWqycq-w_+Bx1cjc+YUhZ11XTj9rfxNiNDojjBx8Fjw@mail.gmail.com
Discussion: https://postgr.es/m/153086788677.17476.8002640580496698831@wrigleys.postgresql.org
2018-07-11 12:07:20 -04:00
Peter Eisentraut 2e78c5b522 Fix assert in nested SQL procedure call
When executing CALL in PL/pgSQL, we need to set a snapshot before
invoking the to-be-called procedure.  Otherwise, the to-be-called
procedure might end up running without a snapshot.  For LANGUAGE SQL
procedures, this would result in an assertion failure.  (For most other
languages, this is usually not a problem, because those use SPI and SPI
sets snapshots in most cases.)  Setting the snapshot restores the
behavior of how CALL worked when it was handled as a generic SQL
statement in PL/pgSQL (exec_stmt_execsql()).

This change revealed another problem:  In SPI_commit(), we popped the
active snapshot before committing the transaction, to avoid "snapshot %p
still active" errors.  However, there is no particular reason why only
at most one snapshot should be on the stack.  So change this to pop all
active snapshots instead of only one.
2018-07-06 23:25:44 +02:00
Andrew Dunstan 1e9c858090 pgindent run prior to branching 2018-06-30 12:25:49 -04:00
Amit Kapila 2e61c50785 Fix thinko in comments.
A slot can not be stored in a tuple but it's vice versa.

Reported-by: Ashutosh Bapat
Author: Ashutosh Bapat
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CAFjFpRcHhNhXdegyJv3KKDWrwO1_NB_KYZM_ZSDeMOZaL1A5jQ@mail.gmail.com
2018-06-27 18:05:24 +05:30
Tom Lane 19832753f1 Fix some ill-chosen names for globally-visible partition support functions.
"compute_hash_value" is particularly gratuitously generic, but IMO
all of these ought to have names clearly related to partitioning.
2018-06-13 13:18:02 -04:00
Tom Lane e23bae82cf Fix up run-time partition pruning's use of relcache's partition data.
The previous coding saved pointers into the partitioned table's relcache
entry, but then closed the relcache entry, causing those pointers to
nominally become dangling.  Actual trouble would be seen in the field
only if a relcache flush occurred mid-query, but that's hardly out of
the question.

While we could fix this by copying all the data in question at query
start, it seems better to just hold the relcache entry open for the
whole query.

While at it, improve the handling of support-function lookups: do that
once per query not once per pruning test.  There's still something to be
desired here, in that we fail to exploit the possibility of caching data
across queries in the fn_extra fields of the relcache's FmgrInfo structs,
which could happen if we just used those structs in-place rather than
copying them.  However, combining that with the possibility of per-query
lookups of cross-type comparison functions seems to require changes in the
APIs of a lot of the pruning support functions, so it's too invasive to
consider as part of this patch.  A win would ensue only for complex
partition key data types (e.g. arrays), so it may not be worth the
trouble.

David Rowley and Tom Lane

Discussion: https://postgr.es/m/17850.1528755844@sss.pgh.pa.us
2018-06-13 12:03:26 -04:00
Tom Lane 69025c5a07 Improve ExecFindInitialMatchingSubPlans's subplan renumbering logic.
We don't need two passes if we scan child partitions before parents,
as that way the children's present_parts are up to date before they're
needed.  I (tgl) think there's actually a bug being fixed here, for the
case of an intermediate partitioned table with no direct leaf children,
but haven't attempted to construct a test case to prove it.

David Rowley

Discussion: https://postgr.es/m/CAKJS1f-6GODRNgEtdPxCnAPme2h2hTztB6LmtfdmcYAAOE0kQg@mail.gmail.com
2018-06-11 17:35:53 -04:00
Alvaro Herrera 5b0c7e2f75 Don't needlessly check the partition contraint twice
Starting with commit f0e44751d7, ExecConstraints was in charge of
running the partition constraint; commit 19c47e7c82 modified that so
that caller could request to skip that checking depending on some
conditions, but that commit and 15ce775faa together introduced a small
bug there which caused ExecInsert to request skipping the constraint
check but have this not be honored -- in effect doing the check twice.
This could have been fixed in a very small patch, but on further
analysis of the involved function and its callsites, it turns out to be
simpler to give the responsibility of checking the partition constraint
fully to the caller, and return ExecConstraints to its original
(pre-partitioning) shape where it only checked tuple descriptor-related
constraints.  Each caller must do partition constraint checking on its
own schedule, which is more convenient after commit 2f17844104 anyway.

Reported-by: David Rowley
Author: David Rowley, Álvaro Herrera
Reviewed-by: Amit Langote, Amit Khandekar, Simon Riggs
Discussion: https://postgr.es/m/CAKJS1f8w8+awsxgea8wt7_UX8qzOQ=Tm1LD+U1fHqBAkXxkW2w@mail.gmail.com
2018-06-11 17:12:16 -04:00
Peter Eisentraut 387543f7bd Make new error code name match SQL standard more closely
Discussion: https://www.postgresql.org/message-id/dff3d555-bea4-ac24-29b2-29521b9d08e8%402ndquadrant.com
2018-06-11 11:15:28 -04:00
Tom Lane 321f648a31 Assorted cosmetic cleanup of run-time-partition-pruning code.
Use "subplan" rather than "subnode" to refer to the child plans of
a partitioning Append; this seems a bit more specific and hence
clearer.  Improve assorted comments.  No non-cosmetic changes.

David Rowley and Tom Lane

Discussion: https://postgr.es/m/CAFj8pRBjrufA3ocDm8o4LPGNye9Y+pm1b9kCwode4X04CULG3g@mail.gmail.com
2018-06-10 18:24:34 -04:00
Tom Lane 939449de0e Relocate partition pruning structs to a saner place.
These struct definitions were originally dropped into primnodes.h,
which is a poor choice since that's mainly intended for primitive
expression node types; these are not in that category.  What they
are is auxiliary info in Plan trees, so move them to plannodes.h.

For consistency, also relocate some related code that was apparently
placed with the aid of a dartboard.

There's no interesting code changes in this commit, just reshuffling.

David Rowley and Tom Lane

Discussion: https://postgr.es/m/CAFj8pRBjrufA3ocDm8o4LPGNye9Y+pm1b9kCwode4X04CULG3g@mail.gmail.com
2018-06-10 16:30:14 -04:00
Tom Lane 73b7f48f78 Improve run-time partition pruning to handle any stable expression.
The initial coding of the run-time-pruning feature only coped with cases
where the partition key(s) are compared to Params.  That is a bit silly;
we can allow it to work with any non-Var-containing stable expression, as
long as we take special care with expressions containing PARAM_EXEC Params.
The code is hardly any longer this way, and it's considerably clearer
(IMO at least).  Per gripe from Pavel Stehule.

David Rowley, whacked around a bit by me

Discussion: https://postgr.es/m/CAFj8pRBjrufA3ocDm8o4LPGNye9Y+pm1b9kCwode4X04CULG3g@mail.gmail.com
2018-06-10 15:22:32 -04:00
Thomas Munro 86a2218eb0 Limit Parallel Hash's bucket array to MaxAllocSize.
Make sure that we don't exceed MaxAllocSize when increasing the number of
buckets.  Perhaps later we'll remove that limit and use DSA_ALLOC_HUGE, but
for now just prevent further increases like the non-parallel code.  This
change avoids the error from bug report #15225.

Author: Thomas Munro
Reviewed-By: Tom Lane
Reported-by: Frits Jalvingh
Discussion: https://postgr.es/m/152802081668.26724.16985037679312485972%40wrigleys.postgresql.org
2018-06-10 20:30:25 +12:00
Peter Eisentraut acad8b409a Fix typo 2018-06-08 11:55:12 -04:00
Heikki Linnakangas 57f06a7611 Fix obsolete comment.
The 'orig_slot' argument was removed in commit c0a8ae7be3, but that
commit forgot to update the comment.

Author: Amit Langote
Discussion: https://www.postgresql.org/message-id/194ac4bf-7b4a-c887-bf26-bc1a85ea995a@lab.ntt.co.jp
2018-06-07 09:56:22 +03:00
Tom Lane f755a152d4 Improve spelling of new FINALFUNC_MODIFY aggregate attribute.
I'd used SHARABLE as a value originally, but Peter Eisentraut points out
that dictionaries agree that SHAREABLE is the preferred spelling.
Run around and change that before it's too late.

Discussion: https://postgr.es/m/d2e1afd4-659c-50d6-1b20-7cfd3675e909@2ndquadrant.com
2018-05-21 11:41:42 -04:00