On Wed, Feb 1, 2012 at 10:42 PM, Jim Nasby <j...@nasby.net> wrote: > On Feb 1, 2012, at 4:25 AM, Simon Riggs wrote: >> At present log_newpage() produces log records called XLOG_HEAP_NEWPAGE. >> >> That routine is used by HEAP, BTREE, GIN, SPGIST rmgrs, as well as >> various forks. >> >> WAL contains no information as to which rmgr the data refers to, >> making debugging much harder and skewing efforts to optimise WAL >> traffic and is a pretty gross modularity violation of the whole rmgr >> concept. >> >> This refactoring adds an RmgrId field onto each new page record and >> makes clearer that certain "heap" routines are actually generic. The >> WAL records are still marked as HEAP rmgr and have XLOG_NEWPAGE record >> type, but at least we can tell them apart. (We already had forknum, >> just not rmgrid). > > > But we already had RelFileNode; wouldn't that be enough to tell what rmgr was > responsible for the new page? Can 2 different rmgrs write to the same file > node?
No, but which one? No way to tell unless you have full list of relfilenodes and check each one. So btree changes look like heap changes etc.. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
