On Tue, Jun 30, 2015 at 8:57 AM, Lukasz Wrobel < lukasz.wro...@motorolasolutions.com> wrote: > > > Perhaps I'm missing some indexes on the tables (creating them on the > columns on which the where clause was used in the long queries seemed to > halve their times). Also how can I monitor my transactions and if they are > closed properly? >
To track transactions that have not been left idle but not committed or rolled back you would: 1) Set track_activities true in the config (doc: http://www.postgresql.org/docs/current/static/runtime-config-statistics.html#GUC-TRACK-ACTIVITIES ) 2) Query the pg_stat_activity view for connections where state = 'idle in transaction' (doc: http://www.postgresql.org/docs/current/static/monitoring-stats.html#PG-STAT-ACTIVITY-VIEW ) As you would suspect, transactions that have been left "idle in transaction" prevent vacuum from removing old tuples (because they are still in scope for that transaction) *Will J. Dunn* *willjdunn.com <http://willjdunn.com>* On Tue, Jun 30, 2015 at 4:27 PM, William Dunn <dunn...@gmail.com> wrote: > Hello Lukasz, > > On Tue, Jun 30, 2015 at 8:57 AM, Lukasz Wrobel < > lukasz.wro...@motorolasolutions.com> wrote: > >> >> There doesn't seem to be any issues with disk space, memory or CPU, as >> neither of those is even 50% used (as per df and top). >> > > Are you using the default PostgreSQL configuration settings, or have you > custom tuned them? The default settings are targeted for wide compatibility > and are not optimized for performance. If PostgreSQL is performing badly > and using a small amount of system resources it is likely some tuning is > needed. See docs: > http://www.postgresql.org/docs/current/static/runtime-config.html > > > On Tue, Jun 30, 2015 at 8:57 AM, Lukasz Wrobel < > lukasz.wro...@motorolasolutions.com> wrote: > >> >> For whatever reason there is also no data in pg_stat* tables. >> > > You can also turn on tracking (for statistics views) by enabling > statistics collection in the config > http://www.postgresql.org/docs/current/static/runtime-config-statistics.html > > *Will J. Dunn* > *willjdunn.com <http://willjdunn.com>* > > On Tue, Jun 30, 2015 at 8:57 AM, Lukasz Wrobel < > lukasz.wro...@motorolasolutions.com> wrote: > >> Hello. >> >> I have multiple problems with my database, the biggest of which is how to >> find out what is actually wrong. >> >> First of all I have a 9.3 postgres database that is running for about a >> month. Right now the queries on that database are running very slowly >> (select with a simple "where" on a non-indexed column on a table with about >> 5000 records takes 1,5s, a complicated hibernate select with 7 joins on >> tables of about 5000 records takes about 15s, insert or update on a table >> with 35000 records takes up to 20 mins). >> >> The tables and indexes on those tables are bloated to the point where >> this query: https://wiki.postgresql.org/wiki/Show_database_bloat shows >> wasted bytes in hundreds of MB. >> >> For whatever reason there is also no data in pg_stat* tables. >> >> So due to the long query times, there are multiple errors in my >> application logs like "No free connection available" or "Could not >> synchronize database state with session", or "Failed to rollback >> transaction" and the application fails to start in the required time. >> >> The only thing that helps fix the situation seems to be vacuum full of >> the entire database. Regular vacuum doesn't even lower the dead tuples >> count (which appear by the thousands during application launching). Reindex >> of all the indexes in the database didn't help as well. All autovacuum >> parameters are default. >> >> There doesn't seem to be any issues with disk space, memory or CPU, as >> neither of those is even 50% used (as per df and top). >> >> Is there any good tool that will monitor the queries and generate a >> report with useful information on what might be the problem? I tried >> pg_badger, but all I got were specific queries and their times, but the >> long query times are just one of the symptoms of what's wrong with the >> database, not the cause. >> >> Perhaps I'm missing some indexes on the tables (creating them on the >> columns on which the where clause was used in the long queries seemed to >> halve their times). Also how can I monitor my transactions and if they are >> closed properly? >> >> I will be grateful for any help and if you need more details I can >> provide them if possible. >> >> Best regards. >> Lukasz >> > >
