On Tue, Nov 22, 2016 at 1:49 AM, Craig Ringer <cr...@2ndquadrant.com> wrote: > On 22 November 2016 at 10:20, Craig Ringer <cr...@2ndquadrant.com> wrote: >> I'm currently looking at making detection of replay conflict with a >> slot work by separating the current catalog_xmin into two effective >> parts - the catalog_xmin currently needed by any known slots >> (ProcArray->replication_slot_catalog_xmin, as now), and the oldest >> actually valid catalog_xmin where we know we haven't removed anything >> yet. > > OK, more detailed plan. > > The last checkpoint's oldestXid, and ShmemVariableCache's oldestXid, > are already held down by ProcArray's catalog_xmin. But that doesn't > mean we haven't removed newer tuples from specific relations and > logged that in xl_heap_clean, etc, including catalogs or user > catalogs, it only means the clog still exists for those XIDs.
Really? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers