On Wed, Mar 19, 2014 at 9:04 PM, Pavel Stehule <pavel.stehule@gmail.com> wrote: > Hello > > I wrote a few patches, that we use in our production. These patches are > small, but I hope, so its can be interesting for upstream: > > 1. cancel time - we log a execution time cancelled statements > > 2. fatal verbose - this patch ensure a verbose log for fatal errors. It > simplify a investigation about reasons of error. > > 3. relation limit - possibility to set session limit for maximum size of > relations. Any relation cannot be extended over this limit in session, when > this value is higher than zero. Motivation - we use lot of queries like > CREATE TABLE AS SELECT .. , and some very big results decreased a disk free > space too much. It was high risk in our multi user environment. Motivation > is similar like temp_files_limit.
So if there is error on reaching max threshold size, won't it loose all data or is that expected?
Exception is expected
Also I think it might not be applicable for all table inserts, as normally checkpointer/bgrwriter flushes data, so you might not be able to estimate size immediately when your SQL statement is executing.
Won't it better to have LIMIT Rows in Select statement or generically have table level option for Max Rows?
It significantly harder to expect N for LIMIT - there are lot of varlena types, so sometimes you can be too strict, sometimes you can be too tolerant