diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2011-08-14 15:40:41 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2011-08-14 15:40:41 -0400 |
| commit | 3c96f5c647852d1c77f9854cf1f78dfb01af8631 (patch) | |
| tree | e8574136d2dc0289a6c6b99eb80d3eda61ba0e44 /src/backend/access/gist/gistsplit.c | |
| parent | ceaf5052c6a7bee794211f5d4c503639bdf3dff0 (diff) | |
| download | postgresql-3c96f5c647852d1c77f9854cf1f78dfb01af8631.tar.gz postgresql-3c96f5c647852d1c77f9854cf1f78dfb01af8631.zip | |
Fix unsafe order of operations in foreign-table DDL commands.
When updating or deleting a system catalog tuple, it's necessary to acquire
RowExclusiveLock on the catalog before looking up the tuple; otherwise a
concurrent VACUUM FULL on the catalog might move the tuple to a different
TID before we can apply the update. Coding patterns that find the tuple
via a table scan aren't at risk here, but when obtaining the tuple from a
catalog cache, correct ordering is important; and several routines in
foreigncmds.c got it wrong. Noted while running the regression tests in
parallel with VACUUM FULL of assorted system catalogs.
For consistency I moved all the heap_open calls to the starts of their
functions, including a couple for which there was no actual bug.
Back-patch to 8.4 where foreigncmds.c was added.
Diffstat (limited to 'src/backend/access/gist/gistsplit.c')
0 files changed, 0 insertions, 0 deletions