Jakub Ouhrabka <kuba@xxxxxxxxxx> writes: > What does it mean? Look at src/include/storage/sinval.h and src/include/utils/syscache.h. What you seem to have here is a bunch of tuple updates in pg_class (invalidating caches 29 and 30, which in 8.2 correspond to RELNAMENSP and RELOID), followed by a bunch of SharedInvalRelcacheMsg and SharedInvalSmgrMsg. What I find interesting is that the hits are coming against nearly-successive tuple CTIDs in pg_class, eg these are all on pages 25 and 26 of pg_class: > LOG: sending inval msg 30 0 25 45 30036 4294936595 > LOG: sending inval msg 29 0 25 45 30036 2019111801 > LOG: sending inval msg 30 0 26 11 30036 4294936595 > LOG: sending inval msg 29 0 26 11 30036 2019111801 > LOG: sending inval msg 30 0 25 44 30036 4294936597 > LOG: sending inval msg 29 0 25 44 30036 3703878920 > LOG: sending inval msg 30 0 26 10 30036 4294936597 > LOG: sending inval msg 29 0 26 10 30036 3703878920 > LOG: sending inval msg 30 0 26 9 30036 4294936616 > LOG: sending inval msg 29 0 26 9 30036 3527122063 > LOG: sending inval msg 30 0 25 43 30036 4294936616 > LOG: sending inval msg 29 0 25 43 30036 3527122063 The ordering is a little strange --- not sure what's producing that. I can think of three things that might be producing this: 1. DDL operations ... but most sorts of DDL on a table would touch more catalogs than just pg_class, so this is a bit hard to credit. 2. VACUUM. 3. Some sort of direct update of pg_class. The fact that we have a bunch of catcache invals followed by relcache/smgr invals says that this all happened in one transaction, else they'd have been intermixed better. That lets VACUUM off the hook, because it processes each table in a separate transaction. I am wondering if maybe your app does one of those sneaky things like fooling with pg_class.reltriggers. If so, the problem might be soluble by just avoiding unnecessary updates. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org