Hi, We got a very strange nbtree corruption report some time ago. This was a btree index on a vey high churn table -- entries are updated and deleted very quickly, so the index grows very large and also shrinks quickly (AFAICT this is a work queue of sorts).
The most strange thing of all is that there was this error: ERROR: left link changed unexpectedly in block 3378 of index "index_name" CONTEXT: automatic vacuum of table "table_name" This was reported not once, but several dozens of times, by each new autovacuum worker that tried to vacuum the table. As far as I can see, there is just no way for this to happen ... much less happen repeatedly. I thought it might be related to concurrent insertions somehow managing to split the page under deletion very quickly (given the load these systems are under, this is plausible). But I can't find how. (There were other error reports of btree indexes going awry here, such as "ERROR: right sibling's left-link doesn't match: block 67 links to 2118 instead of expected 2228 in index "pg_depend_depender_index"). These guys are running 8.3.14 here, and this is a Londiste slave database. Sadly, it seems that the index files in our case are gone now. I see three independent reports of this error message in the archives (Ulrich Wisser, Mark Kirkwood, Gabriel Ferro), but no one seems to have carried the investigation forward enough to discover what is exactly going wrong. Any thoughts about this? -- Álvaro Herrera <alvhe...@alvh.no-ip.org> -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers