Re: Memory leak in PL/pgSQL function which CREATE/SELECT/DROP a temporary table

From: "Heikki Linnakangas" <hlinnakangas@vmware.com>

On 18.06.2013 15:48, Heikki Linnakangas wrote:

Hmm. I could repeat this, and it seems that the catcache for
pg_statistic accumulates negative cache entries. Those slowly take up
the memory.

Digging a bit deeper, this is a rather common problem with negative catcache entries. In general, nothing stops you from polluting the cache with as many negative cache entries as you like. Just do "select * from table_that_doesnt_exist" for as many non-existent table names as you want, for example. Those entries are useful at least in theory; they speed up throwing the error the next time you try to query the same non-existent table.

Really?  Would the catcache be polluted with entries for nonexistent tables? I'm surprised at this.  I don't think it is necessary to speed up the query that fails with nonexistent tables, because such queries should be eliminated during application development.