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Postgres FD Implementation
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  1. 13 Jul, 2018 7 commits
  3. 12 Jul, 2018 12 commits
  5. 11 Jul, 2018 8 commits
    • Tom Lane's avatar
      Mark built-in btree comparison functions as leakproof where it's safe. · 39a96512
      Tom Lane authored 
      Generally, if the comparison operators for a datatype or pair of datatypes
are leakproof, the corresponding btree comparison support function can be
considered so as well.  But we had not originally worried about marking
support functions as leakproof, reasoning that they'd not likely be used in
queries so the marking wouldn't matter.  It turns out there's at least one
place where it does matter: calc_arraycontsel() finds the target datatype's
default btree comparison function and tries to use that to estimate
selectivity, but it will be blocked in some cases if the function isn't
leakproof.  This leads to unnecessarily poor selectivity estimates and bad
plans, as seen in bug #15251.

Hence, run around and apply proleakproof markings where the corresponding
btree comparison operators are leakproof.  (I did eyeball each function
to verify that it wasn't doing anything surprising, too.)

This isn't a full solution to bug #15251, and it's not back-patchable
because of the need for a catversion bump.  A more useful response probably
is to consider whether we can check permissions on the parent table instead
of the child.  However, this change will help in some cases where that
won't, and it's easy enough to do in HEAD, so let's do so.

Discussion: https://postgr.es/m/3876.1531261875@sss.pgh.pa.us
      39a96512
    • Tom Lane's avatar
      Fix create_scan_plan's handling of sortgrouprefs for physical tlists. · 57cd2b6e
      Tom Lane authored 
      We should only run apply_pathtarget_labeling_to_tlist if CP_LABEL_TLIST
was specified, because only in that case has use_physical_tlist checked
that the labeling will succeed; otherwise we may get an "ORDER/GROUP BY
expression not found in targetlist" error.  (This subsumes the previous
test about gating_clauses, because we reset "flags" to zero earlier
if there are gating clauses to apply.)

The only known case in which a failure can occur is with a ProjectSet
path directly atop a table scan path, although it seems likely that there
are other cases or will be such in future.  This means that the failure
is currently only visible in the v10 branch: 9.6 didn't have ProjectSet,
while in v11 and HEAD, apply_scanjoin_target_to_paths for some weird
reason is using create_projection_path not apply_projection_to_path,
masking the problem because there's a ProjectionPath in between.

Nonetheless this code is clearly wrong on its own terms, so back-patch
to 9.6 where this logic was introduced.

Per report from Regina Obe.

Discussion: https://postgr.es/m/001501d40f88$75186950$5f493bf0$@pcorp.us
      57cd2b6e
    • Tom Lane's avatar
      Fix bugs with degenerate window ORDER BY clauses in GROUPS/RANGE mode. · ff4f8891
      Tom Lane authored 
      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
      ff4f8891
    • Alexander Korotkov's avatar
      Fix more wrong paths in header comments · edf59c40
      Alexander Korotkov authored 
      It appears that there are more files, whose header comment paths are
wrong.  So, fix those paths.  No backpatching per proposal of Tom Lane.

Discussion: https://postgr.es/m/CAPpHfdsJyYbOj59MOQL%2B4XxdcomLSLfLqBtAvwR%2BpsCqj3ELdQ%40mail.gmail.com
      edf59c40
    • Alvaro Herrera's avatar
      Rethink how to get float.h in old Windows API for isnan/isinf · f2c58706
      Alvaro Herrera authored 
      We include <float.h> in every place that needs isnan(), because MSVC
used to require it.  However, since MSVC 2013 that's no longer necessary
(cf. commit cec8394b), so we can retire the inclusion to a
version-specific stanza in win32_port.h, where it doesn't need to
pollute random .c files.  The header is of course still needed in a few
places for other reasons.

I (Álvaro) removed float.h from a few more files than in Emre's original
patch.  This doesn't break the build in my system, but we'll see what
the buildfarm has to say about it all.

Author: Emre Hasegeli
Discussion: https://postgr.es/m/CAE2gYzyc0+5uG+Cd9-BSL7NKC8LSHLNg1Aq2=8ubjnUwut4_iw@mail.gmail.com
      f2c58706
    • Alexander Korotkov's avatar
      Fix wrong file path in header comment · a01d0fa1
      Alexander Korotkov authored 
      Header comment of shm_mq.c was mistakenly specifying path to shm_mq.h.
It was introduced in ec9037df.  So, theoretically it could be
backpatched to 9.4, but it doesn't seem to worth it.
      a01d0fa1
    • Thomas Munro's avatar
      Use signals for postmaster death on FreeBSD. · f98b8476
      Thomas Munro authored 
      Use FreeBSD 11.2's new support for detecting parent process death to
make PostmasterIsAlive() very cheap, as was done for Linux in an
earlier commit.

Author: Thomas Munro
Discussion: https://postgr.es/m/7261eb39-0369-f2f4-1bb5-62f3b6083b5e@iki.fi
      f98b8476
    • Thomas Munro's avatar
      Use signals for postmaster death on Linux. · 9f095299
      Thomas Munro authored 
      Linux provides a way to ask for a signal when your parent process dies.
Use that to make PostmasterIsAlive() very cheap.

Based on a suggestion from Andres Freund.

Author: Thomas Munro, Heikki Linnakangas
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/7261eb39-0369-f2f4-1bb5-62f3b6083b5e%40iki.fi
Discussion: https://postgr.es/m/20180411002643.6buofht4ranhei7k%40alap3.anarazel.de
      9f095299
  7. 10 Jul, 2018 5 commits
  9. 09 Jul, 2018 8 commits