On Thu, 2008-06-26 at 11:18 -0400, Tom Lane wrote: > Simon Riggs <[EMAIL PROTECTED]> writes: > > Currently we have a plugin capability for get_relation_info_hook(), but > > no corresponding capability for statistics info. > > > So, all calls to SearchSysCache would be replaced with a call to > > get_relation_info_hook(), if present. > > Surely you didn't mean ALL calls. Please be more specific about what > you're proposing.
The statistics relation STATRELATT is accessed in a few places in the planner. Since it is in the syscache it is accessed directly from there. I would like to add hooks so that stats data can come from somewhere else other than the syscache for tables, just as we can already do with get_relation_stats_hook(). These new changes would complete the existing feature to ensure it is fully usabled in the way originally intended. In selfunc.c: There are 3 calls to SearchSysCache(STATRELATT,...). In lsyscache.c: There is 1 call to SearchSysCache(STATRELATT...) in get_attavgwidth() and 2 calls to SysCacheGetAttr(STATRELATT...) in get_attstatsslot(). Calls to SearchSysCache(STATRELATT...) would be replaced by a call to an external module, if present, with a function pointer to get_relation_stats_hook(). This returns a tuple with stats info about that relation. Calls to SysCacheGetAttr(STATRELATT...) would be replaced by a call to an external module, if present with a function pointer to get_attribute_stats_hook(). This returns a stats slot. The call in ANALYZE would not be touched. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
