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mergepreread()/mergeprereadone() don't exist anymore, the function that
does roughly the same is now called mergereadnext().
This commit is contained in:
Heikki Linnakangas 2016-10-04 09:46:43 +03:00
parent 61633f7904
commit c86c2d9d57
1 changed files with 8 additions and 8 deletions
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16
src/backend/utils/sort/tuplesort.c
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@ -3083,14 +3083,14 @@ dumpbatch(Tuplesortstate *state, bool alltuples)
* a call with no subsequent run actually written to destTape), we prefer
* to write out a 0 tuple run.
*
* mergepreread()/mergeprereadone() are prepared for 0 tuple runs, and
* will reliably mark the tape inactive for the merge when called from
* beginmerge(). This case is therefore similar to the case where
* mergeonerun() finds a dummy run for the tape, and so doesn't need to
* merge a run from the tape (or conceptually "merges" the dummy run, if
* you prefer). According to Knuth, Algorithm D "isn't strictly optimal"
* in its method of distribution and dummy run assignment; this edge case
* seems very unlikely to make that appreciably worse.
* mergereadnext() is prepared for 0 tuple runs, and will reliably mark
* the tape inactive for the merge when called from beginmerge(). This
* case is therefore similar to the case where mergeonerun() finds a dummy
* run for the tape, and so doesn't need to merge a run from the tape (or
* conceptually "merges" the dummy run, if you prefer). According to
* Knuth, Algorithm D "isn't strictly optimal" in its method of
* distribution and dummy run assignment; this edge case seems very
* unlikely to make that appreciably worse.
*/
Assert(state->status == TSS_BUILDRUNS);