William Dunn <dunn...@gmail.com> writes:

> Sorry I meant to say, "To track transactions that have been left idle but not 
> committed or rolled back you would..."
> Typo


foodb/postgres
=# \d pg_stat_activity|pg_prepared_xacts
        View "pg_catalog.pg_prepared_xacts"
   Column    |           Type           | Modifiers 
-------------+--------------------------+-----------
 transaction | xid                      | 
 gid         | text                     | 
 prepared    | timestamp with time zone | 
 owner       | name                     | 
 database    | name                     | 

           View "pg_catalog.pg_stat_activity"
      Column      |           Type           | Modifiers 
------------------+--------------------------+-----------
 datid            | oid                      | 
 datname          | name                     | 
 pid              | integer                  | 
 usesysid         | oid                      | 
 usename          | name                     | 
 application_name | text                     | 
 client_addr      | inet                     | 
 client_hostname  | text                     | 
 client_port      | integer                  | 
 backend_start    | timestamp with time zone | 
 xact_start       | timestamp with time zone | 
 query_start      | timestamp with time zone | 
 state_change     | timestamp with time zone | 
 waiting          | boolean                  | 
 state            | text                     | 
 query            | text                     | 

foodb/postgres
=# 


>
> Will J. Dunn
> willjdunn.com
>
> On Tue, Jun 30, 2015 at 4:33 PM, William Dunn <dunn...@gmail.com> wrote:
>
>     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
>    
>     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
>        
>         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
>

-- 
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consult...@comcast.net
p: 312.241.7800


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