Обсуждение: How to find the query completeion time?
Hi, Is there a way in Postgres to find when a particular query will finish? For example, for a query like this SELECT * FROM TABLE1 Can we find out from any of the catalog tables(or any other way) when this query is likely to complete? Thanks
On Thursday 2. April 2009, SHARMILA JOTHIRAJAH wrote: >Hi, >Is there a way in Postgres to find when a particular query will > finish? > >For example, for a query like this >SELECT * FROM TABLE1 >Can we find out from any of the catalog tables(or any other way) when > this query is likely to complete? > >Thanks How about EXPLAIN ANALYZE SELECT * FROM TABLE1 ? or just set \timing in the psql and run the query. -- Leif Biberg Kristensen | Registered Linux User #338009 Me And My Database: http://solumslekt.org/blog/
--- On Thu, 4/2/09, Leif B. Kristensen <leif@solumslekt.org> wrote: > From: Leif B. Kristensen <leif@solumslekt.org> > Subject: Re: [GENERAL] How to find the query completeion time? > To: pgsql-general@postgresql.org > Date: Thursday, April 2, 2009, 10:53 AM > On Thursday 2. April 2009, SHARMILA > JOTHIRAJAH wrote: > >Hi, > >Is there a way in Postgres to find when a particular > query will > > finish? > > > >For example, for a query like this > >SELECT * FROM TABLE1 > >Can we find out from any of the catalog tables(or any > other way) when > > this query is likely to complete? > > > >Thanks > > How about > > EXPLAIN ANALYZE SELECT * FROM TABLE1 > > ? > > or just set \timing in the psql and run the query. This will basically execute the query and return the time taken. Is there a way to know when an "already-started" query willend? In ORACLE I can get that information from V$SESSION_LONGOPS view which will give the approx TIME_REMAINING to complete runningqueries. Is there a similar way in postgres? > -- > Leif Biberg Kristensen | Registered Linux User #338009 > Me And My Database: http://solumslekt.org/blog/ > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
> In ORACLE I can get that information from V$SESSION_LONGOPS view which will give the approx TIME_REMAINING to completerunning queries. Is there a similar way in postgres? As far as I know, PostgreSQL has no such facility, and the database server has no idea how long a given query will take to run. I'm not really sure how Oracle does that, given that the performance of a long-running query will vary during its execution. Other queries will begin and end, altering resource availability. Also, if your query runs in several large parts, it can be hard to estimate how quickly parts you haven't started executing yet will run. -- Craig Ringer