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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2011-08-20 14:51:02 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2011-08-20 14:51:25 -0400 |
| commit | 548d1f752be7a11e240f1eadd4f9987a7b9793c5 (patch) | |
| tree | 8fec6fe8794014b6cc2bc9441b6ac5d281483fca /src/backend/executor/execUtils.c | |
| parent | 1ffcc377f692fb227ebfeb6036aa949099d71979 (diff) | |
| download | postgresql-548d1f752be7a11e240f1eadd4f9987a7b9793c5.tar.gz postgresql-548d1f752be7a11e240f1eadd4f9987a7b9793c5.zip | |
Fix performance problem when building a lossy tidbitmap.
As pointed out by Sergey Koposov, repeated invocations of tbm_lossify can
make building a large tidbitmap into an O(N^2) operation. To fix, make
sure we remove more than the minimum amount of information per call, and
add a fallback path to behave sanely if we're unable to fit the bitmap
within the requested amount of memory.
This has been wrong since the tidbitmap code was written, so back-patch
to all supported branches.
Diffstat (limited to 'src/backend/executor/execUtils.c')
0 files changed, 0 insertions, 0 deletions