Обсуждение: Re: Postgres hash tables

Sorry to bother you again but i am having a real hard time getting stats
from the relation. What i have is a shared memory linked list of
relfilenodes. I simply want to get the stats of all these relations and
add them up. I was using pgstat_fetch_stat_tabentry(relid) as an sql
statement and this worked beautifully.
Now i am trying to do it at every
checkpoint before flushing all relations. BUt the above fetch
function does not work. So then i tried getting the stat info from the
relation itself but am having problems with the
RelationNodeCacheGetRelation function which always seems to give me null.
Can you tell me how i can get this info in the backend???
I can see the relation in my list and there is a matching relation in
pg_class. I just need to get the relationdesc back

Just wondering if you shut down postmaster and restart, if the contents of
the file cache are written out to disk or still in the file cache. In
other words, will the number of transactions per second change if you shut
down postmaster and restart compared to restarting the machine
thanks
nailah