On Thu, Dec 22, 2016 at 2:04 AM, Mithun Cy <mithun...@enterprisedb.com> wrote: > There seems to be some base bug in _hash_doinsert(). > + * XXX this is useless code if we are only storing hash keys. > > + */ > > + if (itemsz > HashMaxItemSize((Page) metap)) > > + ereport(ERROR, > > + (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), > > + errmsg("index row size %zu exceeds hash maximum %zu", > > + itemsz, HashMaxItemSize((Page) metap)), > > + errhint("Values larger than a buffer page cannot be > indexed."))); > > "metap" (HashMetaPage) is not a Page (they the entirely different > structure), so above casting is not legal. Added a patch to correct same by > passing actual Page which stores "HashMetaPage".
So, let's see here. HashMaxItemSize uses page only to call PageGetPageSize, which accesses page->pd_pagesize_version, stored 18 bytes into the structure. Instead we're passing it a pointer to HashMetaPageData, where at that offset it will find hashm_bsize which on my system has a value of 8152, which is close enough to the actual page size of 8192 that this check fails to fire in error. It seems like a better idea to declare a new variable for this rather than reusing one of the correct type that happens not to be doing anything during this part of the function, so I committed and back-patched this that way. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers