On Thu, May 21, 2015 at 12:42 AM, Andres Freund <and...@anarazel.de> wrote: > > On 2015-05-20 19:27:05 +0530, Amit Kapila wrote: > > > 13. > > In function replorigin_session_setup() and or > > replorigin_session_advance(), don't we need to WAL log the > > use of Replication state? > > No, the point is that the replication progress is persisted via an extra > data block in the commit record. That's important for both performance > and correctness, because otherwise it gets hard to tie a transaction > made during replay with the update to the progress. Unless you use 2PC > which isn't really an alternative. >
Okay, but what triggered this question was the difference of those functions as compare to when user call function pg_replication_origin_advance(). pg_replication_origin_advance() will WAL log the information during that function call itself (via replorigin_advance()). So even if the transaction issuing pg_replication_origin_advance() function will abort, it will still update the Replication State, why so? With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
