On Mon, May 8, 2017 at 6:30 PM, Dmitriy Sarafannikov <dsarafanni...@yandex.ru> wrote: > > I think we can use RecentGlobalDataXmin for non-catalog relations and > RecentGlobalXmin for catalog relations (probably a check similar to > what we have in heap_page_prune_opt). > > > I took check from heap_page_prune_opt (Maybe this check must be present as > separate function?) > But it requires to initialize snapshot for specific relation. >
+ else \ + (snapshotdata).xmin = \ + TransactionIdLimitedForOldSnapshots(RecentGlobalDataXmin, \ + relation); \ I think we don't need to use TransactionIdLimitedForOldSnapshots() as that is required to override xmin for table vacuum/pruning purposes. > Maybe we need > to use GetOldestXmin()? It is a costly call as it needs ProcArrayLock, so I don't think it makes sense to use it here. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
