postgresql/src/backend/utils
Kevin Grittner 848ef42bb8 Add the "snapshot too old" feature
This feature is controlled by a new old_snapshot_threshold GUC.  A
value of -1 disables the feature, and that is the default.  The
value of 0 is just intended for testing.  Above that it is the
number of minutes a snapshot can reach before pruning and vacuum
are allowed to remove dead tuples which the snapshot would
otherwise protect.  The xmin associated with a transaction ID does
still protect dead tuples.  A connection which is using an "old"
snapshot does not get an error unless it accesses a page modified
recently enough that it might not be able to produce accurate
results.

This is similar to the Oracle feature, and we use the same SQLSTATE
and error message for compatibility.
2016-04-08 14:36:30 -05:00
..
adt Revert CREATE INDEX ... INCLUDING ... 2016-04-08 21:52:13 +03:00
cache Revert CREATE INDEX ... INCLUDING ... 2016-04-08 21:52:13 +03:00
error Introduce a LOG_SERVER_ONLY ereport level, which is never sent to client. 2016-04-04 12:32:42 -04:00
fmgr Properly install dynloader.h on MSVC builds 2016-01-19 23:30:29 -05:00
hash Copyedit comments and documentation. 2016-04-01 21:53:10 -04:00
init Use quicksort, not replacement selection, for external sorting. 2016-04-08 02:36:26 -04:00
mb UCS_to_EUC_JIS_2004.pl: Turn off "test" mode by default 2016-03-16 10:43:05 -04:00
misc Add the "snapshot too old" feature 2016-04-08 14:36:30 -05:00
mmgr Report memory context stats upon out-of-memory in repalloc[_huge]. 2016-03-13 00:21:07 -05:00
resowner Improve ResourceOwners' behavior for large numbers of owned objects. 2016-01-26 15:20:30 -05:00
sort Revert CREATE INDEX ... INCLUDING ... 2016-04-08 21:52:13 +03:00
time Add the "snapshot too old" feature 2016-04-08 14:36:30 -05:00
.gitignore
errcodes.txt Add the "snapshot too old" feature 2016-04-08 14:36:30 -05:00
Gen_dummy_probes.pl Remove dependency on psed for MSVC builds. 2016-03-19 18:36:35 -04:00
Gen_dummy_probes.sed Update copyright for 2016 2016-01-02 13:33:40 -05:00
Gen_fmgrtab.pl Update copyright for 2016 2016-01-02 13:33:40 -05:00
generate-errcodes.pl Update copyright for 2016 2016-01-02 13:33:40 -05:00
Makefile
probes.d Update copyright for 2016 2016-01-02 13:33:40 -05:00