Hi, On Mon, Jul 3, 2017 at 4:10 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Mon, Jul 3, 2017 at 3:24 PM, Ashutosh Sharma <ashu.coe...@gmail.com> wrote: > > On Mon, Jul 3, 2017 at 9:12 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: > >> The basic issue was that the WAL logging for Create Index operation > >> was oblivion of the fact that for unlogged tables only INIT forks need > >> to be logged. Another point which we need to consider is that while > >> replaying the WAL for the create index operation, we need to flush the > >> buffer if it is for init fork. This needs to be done only for pages > >> that can be part of init fork file (like metapage, bitmappage). > >> Attached patch fixes the issue. > >> > >> Another approach to fix the issue could be that always log complete > >> pages for the create index operation on unlogged tables (in > >> hashbuildempty). However, the logic for initial hash index pages > >> needs us to perform certain other actions (like update metapage after > >> the creation of bitmappage) which make it difficult to follow that > >> approach. > >> > > > > Thanks for sharing the steps to reproduce the issue in detail. I could > > easily reproduce this issue. I also had a quick look into the patch and the > > fix looks fine to me. However, it would be good if we can add at least one > > test for unlogged table with hash index in the regression test suite. > > > > There is already such a test, see create_index.sql. > CREATE UNLOGGED TABLE unlogged_hash_table (id int4); > CREATE INDEX unlogged_hash_index ON unlogged_hash_table USING hash (id > int4_ops); > > Do you have something else in mind?
Yes, that's what i had in my mind. But, good to know that we already have a test-case with hash index created on an unlogged table. > > > I think the problem mentioned in this thread can be caught only if we > promote the standby and restart it. We might be able to write it > using TAP framework, but I think such a test should exist for other > index types as well or in general for unlogged tables. I am not > opposed to writing such a test if you and or others feel so. I think, it would be a good thing to add such test cases using TAP framework but as you said, it would be good to take others opinion as well on this. Thanks. > > > Apart from that i have tested the patch and the patch seems to be working > > fine. > > Thanks. > > -- > With Regards, > Amit Kapila. > EnterpriseDB: http://www.enterprisedb.com -- With Regards, Ashutosh Sharma EnterpriseDB:http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers