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  1. 06 Apr, 2017 7 commits
    • Heikki Linnakangas's avatar
      Remove bogus SCRAM_ITERATION_LEN constant. · 07044efe
      Heikki Linnakangas authored 
      It was not used for what the comment claimed, at all. It was actually used
as the 'base' argument to strtol(), when reading the iteration count. We
don't need a constant for base-10, so remove it.
      07044efe
    • Simon Riggs's avatar
      Always SnapshotResetXmin() during ClearTransaction() · cd0cebaf
      Simon Riggs authored 
      Avoid corner cases during 2PC with 6bad580d
      cd0cebaf
    • Peter Eisentraut's avatar
      Identity columns · 32173270
      Peter Eisentraut authored 
      This is the SQL standard-conforming variant of PostgreSQL's serial
columns.  It fixes a few usability issues that serial columns have:

- CREATE TABLE / LIKE copies default but refers to same sequence
- cannot add/drop serialness with ALTER TABLE
- dropping default does not drop sequence
- need to grant separate privileges to sequence
- other slight weirdnesses because serial is some kind of special macro
Reviewed-by: default avatarVitaly Burovoy <vitaly.burovoy@gmail.com>
      32173270
    • Simon Riggs's avatar
      Avoid SnapshotResetXmin() during AtEOXact_Snapshot() · 6bad580d
      Simon Riggs authored 
      For normal commits and aborts we already reset PgXact->xmin,
so we can simply avoid running SnapshotResetXmin() twice.

During performance tests by Alexander Korotkov, diagnosis
by Andres Freund showed PgXact array as a bottleneck. After
manual analysis by me of the code paths that touch those
memory locations, I was able to identify extraneous code
in the main transaction commit path.

Avoiding touching highly contented shmem improves concurrent
performance slightly on all workloads, confirmed by tests
run by Ashutosh Sharma and Alexander Korotkov.

Simon Riggs

Discussion: CANP8+jJdXE9b+b9F8CQT-LuxxO0PBCB-SZFfMVAdp+akqo4zfg@mail.gmail.com
      6bad580d
    • Heikki Linnakangas's avatar
      Remove dead code and fix comments in fast-path function handling. · fd019835
      Heikki Linnakangas authored 
      HandleFunctionRequest() is no longer responsible for reading the protocol
message from the client, since commit 2b3a8b20. Fix the outdated
comments.

HandleFunctionRequest() now always returns 0, because the code that used
to return EOF was moved in 2b3a8b20. Therefore, the caller no longer
needs to check the return value.

Reported by Andres Freund. Backpatch to all supported versions, even though
this doesn't have any user-visible effect, to make backporting future
patches in this area easier.

Discussion: https://www.postgresql.org/message-id/20170405010525.rt5azbya5fkbhvrx@alap3.anarazel.de
      fd019835
    • Andres Freund's avatar
      Code review for recent slot.c changes. · 5c21ad07
      Andres Freund authored
      5c21ad07
    • Tom Lane's avatar
      Fix integer-overflow problems in interval comparison. · df1a699e
      Tom Lane authored 
      When using integer timestamps, the interval-comparison functions tried
to compute the overall magnitude of an interval as an int64 number of
microseconds.  As reported by Frazer McLean, this overflows for intervals
exceeding about 296000 years, which is bad since we nominally allow
intervals many times larger than that.  That results in wrong comparison
results, and possibly in corrupted btree indexes for columns containing
such large interval values.

To fix, compute the magnitude as int128 instead.  Although some compilers
have native support for int128 calculations, many don't, so create our
own support functions that can do 128-bit addition and multiplication
if the compiler support isn't there.  These support functions are designed
with an eye to allowing the int128 code paths in numeric.c to be rewritten
for use on all platforms, although this patch doesn't do that, or even
provide all the int128 primitives that will be needed for it.

Back-patch as far as 9.4.  Earlier releases did not guard against overflow
of interval values at all (commit 146604ec fixed that), so it seems not
very exciting to worry about overly-large intervals for them.

Before 9.6, we did not assume that unreferenced "static inline" functions
would not draw compiler warnings, so omit functions not directly referenced
by timestamp.c, the only present consumer of int128.h.  (We could have
omitted these functions in HEAD too, but since they were written and
debugged on the way to the present patch, and they look likely to be needed
by numeric.c, let's keep them in HEAD.)  I did not bother to try to prevent
such warnings in a --disable-integer-datetimes build, though.

Before 9.5, configure will never define HAVE_INT128, so the part of
int128.h that exploits a native int128 implementation is dead code in the
9.4 branch.  I didn't bother to remove it, thinking that keeping the file
looking similar in different branches is more useful.

In HEAD only, add a simple test harness for int128.h in src/tools/.

In back branches, this does not change the float-timestamps code path.
That's not subject to the same kind of overflow risk, since it computes
the interval magnitude as float8.  (No doubt, when this code was originally
written, overflow was disregarded for exactly that reason.)  There is a
precision hazard instead :-(, but we'll avert our eyes from that question,
since no complaints have been reported and that code's deprecated anyway.

Kyotaro Horiguchi and Tom Lane

Discussion: https://postgr.es/m/1490104629.422698.918452336.26FA96B7@webmail.messagingengine.com
      df1a699e
  3. 05 Apr, 2017 12 commits
  5. 04 Apr, 2017 20 commits
  7. 03 Apr, 2017 1 commit
    • Andrew Gierth's avatar
      Try and silence spurious Coverity warning. · f5780935
      Andrew Gierth authored 
      gset_data (aka gd) in planner.c is always non-null if and only if
parse->groupingSets is non-null, but Coverity doesn't know that and
complains.  Feed it an assertion to see if that keeps it happy.
      f5780935