mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2025-01-30 19:00:29 +08:00
Code Issues Packages Projects Releases Wiki Activity

Don't use abbreviated keys for the final merge pass.

Browse Source 
When we write tuples out to disk and read them back in, the abbreviated
keys become non-abbreviated, because the readtup routines don't know
anything about abbreviation.  But without this fix, the rest of the
code still thinks the abbreviation-aware compartor should be used,
so chaos ensues.

Report by Andrew Gierth; patch by Peter Geoghegan.
This commit is contained in:
Robert Haas 2015-01-23 11:58:31 -05:00
parent 6a3c6ba0ba
commit 5cefbf5a6c
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/backend/utils/sort/tuplesort.c
View File

@ -2172,6 +2172,22 @@ mergeruns(Tuplesortstate *state)
return;
}
if (state->sortKeys->abbrev_converter)
{
/*
* If there are multiple runs to be merged, when we go to read back
* tuples from disk, abbreviated keys will not have been stored, and we
* don't care to regenerate them. Disable abbreviation from this point
* on.
*/
state->sortKeys->abbrev_converter = NULL;
state->sortKeys->comparator = state->sortKeys->abbrev_full_comparator;
/* Not strictly necessary, but be tidy */
state->sortKeys->abbrev_abort = NULL;
state->sortKeys->abbrev_full_comparator = NULL;
}
/* End of step D2: rewind all output tapes to prepare for merging */
for (tapenum = 0; tapenum < state->tapeRange; tapenum++)
LogicalTapeRewind(state->tapeset, tapenum, false);