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  1. 13 Jun, 2020 7 commits
  3. 12 Jun, 2020 4 commits
    • David Rowley's avatar
      Add missing extern keyword for a couple of numutils functions · 9a7fccd9
      David Rowley authored 
      In passing, also remove a few surplus empty lines from pg_ltoa and
pg_ulltoa_n in numutils.c

Reported-by: Andrew Gierth
Discussion: https://postgr.es/m/87y2ou3xuh.fsf@news-spur.riddles.org.uk
Backpatch-through: 13, where these changes were introduced
      9a7fccd9
    • Tom Lane's avatar
      Avoid using a cursor in plpgsql's RETURN QUERY statement. · 2f48ede0
      Tom Lane authored 
      plpgsql has always executed the query given in a RETURN QUERY command
by opening it as a cursor and then fetching a few rows at a time,
which it turns around and dumps into the function's result tuplestore.
The point of this was to keep from blowing out memory with an oversized
SPITupleTable result (note that while a tuplestore can spill tuples
to disk, SPITupleTable cannot).  However, it's rather inefficient, both
because of extra data copying and because of executor entry/exit
overhead.  In recent versions, a new performance problem has emerged:
use of a cursor prevents use of a parallel plan for the executed query.

We can improve matters by skipping use of a cursor and having the
executor push result tuples directly into the function's result
tuplestore.  However, a moderate amount of new infrastructure is needed
to make that idea work:

* We can use the existing tstoreReceiver.c DestReceiver code to funnel
executor output to the tuplestore, but it has to be extended to support
plpgsql's requirement for possibly applying a tuple conversion map.

* SPI needs to be extended to allow use of a caller-supplied
DestReceiver instead of its usual receiver that puts tuples into
a SPITupleTable.  Two new API calls are needed to handle both the
RETURN QUERY and RETURN QUERY EXECUTE cases.

I also felt that I didn't want these new API calls to use the legacy
method of specifying query parameter values with "char" null flags
(the old ' '/'n' convention); rather they should accept ParamListInfo
objects containing the parameter type and value info.  This required
a bit of additional new infrastructure since we didn't yet have any
parse analysis callback that would interpret $N parameter symbols
according to type data supplied in a ParamListInfo.  There seems to be
no harm in letting makeParamList install that callback by default,
rather than leaving a new ParamListInfo's parserSetup hook as NULL.
(Indeed, as of HEAD, I couldn't find anyplace that was using the
parserSetup field at all; plpgsql was using parserSetupArg for its
own purposes, but parserSetup seemed to be write-only.)

We can actually get plpgsql out of the business of using legacy null
flags altogether, and using ParamListInfo instead of its ad-hoc
PreparedParamsData structure; but this requires inventing one more
SPI API call that can replace SPI_cursor_open_with_args.  That seems
worth doing, though.

SPI_execute_with_args and SPI_cursor_open_with_args are now unused
anywhere in the core PG distribution.  Perhaps someday we could
deprecate/remove them.  But cleaning up the crufty bits of the SPI
API is a task for a different patch.

Per bug #16040 from Jeremy Smith.  This is unfortunately too invasive to
consider back-patching.  Patch by me; thanks to Hamid Akhtar for review.

Discussion: https://postgr.es/m/16040-eaacad11fecfb198@postgresql.org
      2f48ede0
    • Michael Paquier's avatar
      Fix typos and some format mistakes in comments · aaf8c990
      Michael Paquier authored 
      Author: Justin Pryzby
Discussion: https://postgr.es/m/20200612023709.GC14879@telsasoft.com
      aaf8c990
    • Peter Eisentraut's avatar
      Make more use of RELKIND_HAS_STORAGE() · ffd25822
      Peter Eisentraut authored 
      Make use of RELKIND_HAS_STORAGE() where appropriate, instead of
listing out the relkinds individually.  No behavior change intended.
Reviewed-by: default avatarTom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/7a22bf51-2480-d999-1794-191ba67ff47c%402ndquadrant.com
      ffd25822
  5. 11 Jun, 2020 12 commits
  7. 10 Jun, 2020 4 commits
  9. 09 Jun, 2020 6 commits
  11. 08 Jun, 2020 5 commits
  13. 07 Jun, 2020 2 commits