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
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src	Add the "snapshot too old" feature	2016-04-08 14:36:30 -05:00
bug.template	Stamp HEAD as 9.6devel.	2015-06-30 14:01:15 -04:00
KNOWN_BUGS	Remove extra newlines at end and beginning of files, add missing newlines	2010-08-19 05:57:36 +00:00
Makefile	Remove maintainer-check target, fold into normal build	2013-10-10 20:11:56 -04:00
MISSING_FEATURES	Remove extra newlines at end and beginning of files, add missing newlines	2010-08-19 05:57:36 +00:00
TODO	Update URL.	2008-08-21 20:15:31 +00:00