"Josh Berkus" <[EMAIL PROTECTED]> writes: > No, that would be REPEATABLE READ. That's one of the areas where we need to > test HOT; does RR and SERIALIZABLE still work correctly with HOT?
I'm a little confused by your question. REPEATABLE READ is an isolation level we don't directly support in Postgres. If you set the isolation level to REPEATABLE READ you get SERIALIZABLE which is a higher level. HOT works fine with SERIALIZABLE, It uses the same criteria as vacuum for determining when a tuple is dead, namely it compares against RecentGlobalXmin. The check for whether a transaction can see any old tuples in "broken" chains uses the serializable snapshot as a conservative proxy for the oldest snapshot which might be in use. That will work for both serializable and read committed. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
