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Postgres FD Implementation
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  1. 25 Jun, 2019 1 commit
  3. 24 Jun, 2019 10 commits
  5. 23 Jun, 2019 4 commits
    • Noah Misch's avatar
      Don't call PG_RETURN_BOOL() in a function not returning Datum. · 9a81c9fa
      Noah Misch authored 
      This code is new in v12, and the defect probably was not user-visible.
      9a81c9fa
    • Dean Rasheed's avatar
      Add security checks to the multivariate MCV estimation code. · d7f8d26d
      Dean Rasheed authored 
      The multivariate MCV estimation code may run user-defined operators on
the values in the MCV list, which means that those operators may
potentially leak the values from the MCV list. Guard against leaking
data to unprivileged users by checking that the user has SELECT
privileges on the table or all of the columns referred to by the
statistics.

Additionally, if there are any securityQuals on the RTE (either due to
RLS policies on the table, or accessing the table via a security
barrier view), not all rows may be visible to the current user, even
if they have table or column privileges. Thus we further insist that
the operator be leakproof in this case.

Dean Rasheed, reviewed by Tomas Vondra.

Discussion: https://postgr.es/m/CAEZATCUhT9rt7Ui=Vdx4N==VV5XOK5dsXfnGgVOz_JhAicB=ZA@mail.gmail.com
      d7f8d26d
    • Thomas Munro's avatar
      Remove unnecessary comment. · 89ff7c08
      Thomas Munro authored 
      Author: Vik Fearing
Discussion: https://postgr.es/m/150d3e9f-c7ec-3fb3-4fdb-def47c4144af%402ndquadrant.com
      89ff7c08
    • Tom Lane's avatar
      Fix spinlock assembly code for MIPS so it works on MIPS r6. · 1323bfce
      Tom Lane authored 
      Original MIPS-I processors didn't have the LL/SC instructions (nor any
other userland synchronization primitive).  If the build toolchain
targets that ISA variant by default, as an astonishingly large fraction
of MIPS platforms still do, the assembler won't take LL/SC without
coercion in the form of a ".set mips2" instruction.  But we issued that
unconditionally, making it an ISA downgrade for chips later than MIPS2.
That breaks things for the latest MIPS r6 ISA, which encodes these
instructions differently.  Adjust the code so we don't change ISA level
if it's >= 2.

Note that this patch doesn't change what happens on an actual MIPS-I
processor: either the kernel will emulate these instructions
transparently, or you'll get a SIGILL failure.  That tradeoff seemed
fine in 2002 when this code was added (cf 3cbe6b24), and it's even
more so today when MIPS-I is basically extinct.  But let's add a
comment about that.

YunQiang Su (with cosmetic adjustments by me).  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/15844-8f62fe7e163939b3@postgresql.org
      1323bfce
  7. 22 Jun, 2019 1 commit
  9. 20 Jun, 2019 3 commits
  11. 19 Jun, 2019 11 commits
  13. 18 Jun, 2019 3 commits
    • Andres Freund's avatar
      Fix memory corruption/crash in ANALYZE. · 23224563
      Andres Freund authored 
      This fixes an embarrassing oversight I (Andres) made in 737a292b,
namely missing two place where liverows/deadrows were used when
converting those variables to pointers, leading to incrementing the
pointer, rather than the value.

It's not that actually that easy to trigger a crash: One needs tuples
deleted by the current transaction, followed by a tuple deleted in
another session, all in one page. Which is presumably why this hasn't
been noticed before.

Reported-By: Steve Singer
Author: Steve Singer
Discussion: https://postgr.es/m/c7988239-d42c-ddc4-41db-171b23b35e4f@ssinger.info
      23224563
    • Alvaro Herrera's avatar
      Avoid spurious deadlocks when upgrading a tuple lock · 8b21b416
      Alvaro Herrera authored 
      This puts back reverted commit de87a084, with some bug fixes.

When two (or more) transactions are waiting for transaction T1 to release a
tuple-level lock, and transaction T1 upgrades its lock to a higher level, a
spurious deadlock can be reported among the waiting transactions when T1
finishes.  The simplest example case seems to be:

T1: select id from job where name = 'a' for key share;
Y: select id from job where name = 'a' for update; -- starts waiting for T1
Z: select id from job where name = 'a' for key share;
T1: update job set name = 'b' where id = 1;
Z: update job set name = 'c' where id = 1; -- starts waiting for T1
T1: rollback;

At this point, transaction Y is rolled back on account of a deadlock: Y
holds the heavyweight tuple lock and is waiting for the Xmax to be released,
while Z holds part of the multixact and tries to acquire the heavyweight
lock (per protocol) and goes to sleep; once T1 releases its part of the
multixact, Z is awakened only to be put back to sleep on the heavyweight
lock that Y is holding while sleeping.  Kaboom.

This can be avoided by having Z skip the heavyweight lock acquisition.  As
far as I can see, the biggest downside is that if there are multiple Z
transactions, the order in which they resume after T1 finishes is not
guaranteed.

Backpatch to 9.6.  The patch applies cleanly on 9.5, but the new tests don't
work there (because isolationtester is not smart enough), so I'm not going
to risk it.

Author: Oleksii Kliukin
Discussion: https://postgr.es/m/B9C9D7CD-EB94-4635-91B6-E558ACEC0EC3@hintbits.com
Discussion: https://postgr.es/m/2815.1560521451@sss.pgh.pa.us
      8b21b416
    • Thomas Munro's avatar
      Prevent Parallel Hash Join for JOIN_UNIQUE_INNER. · aca127c1
      Thomas Munro authored 
      WHERE EXISTS (...) queries cannot be executed by Parallel Hash Join
with jointype JOIN_UNIQUE_INNER, because there is no way to make a
partial plan totally unique.  The consequence of allowing such plans
was duplicate results from some EXISTS queries.

Back-patch to 11.  Bug #15857.

Author: Thomas Munro
Reviewed-by: Tom Lane
Reported-by: Vladimir Kriukov
Discussion: https://postgr.es/m/15857-d1ba2a64bce0795e%40postgresql.org
      aca127c1
  15. 17 Jun, 2019 6 commits
  17. 16 Jun, 2019 1 commit