Alvaro Herrera wrote: > Tatsuo Ishii wrote: > > > When a transaction aborts, it seems a BRIN index leaves summary data > > which is not valid any more. Is this an expected behavior? I guess > > the answer is yes, because it does not affect correctness of a query > > result, but I would like to make sure. > > You're right, that is not rolled back (just like any other index type, > actually).
Let me clarify this a bit. Summarization normally takes place during vacuum (or upon the brin_summarize_new_ranges() function being called on the table). If the INSERT adds tuples to a page in a range that has already been summarized, then the summary tuple for that page range will be updated to cover the to-be-aborted tuples. On the other hand, if the INSERT adds tuples to a page that is not summarized, there is no summary tuple to update; and the subsequent vacuum will remove those tuples before summarizing the range, so they will not appear in the summary tuple. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers