Very interesting. seems to me like the view might be a bit corrupt then...
not sure...
I think Markus would know more about that

On Sun, Sep 18, 2011 at 11:09 PM, Michal Hruby <email address hidden> wrote:

> And concluding:
>
> SELECT subj_id, max(timestamp) AS timestamp
>   FROM event_view
>    WHERE (((subj_uri = 'application://gedit.desktop')
>           OR (subj_uri = 'application://devhelp.desktop')
>           OR (subj_uri = 'application://google-chrome.desktop') OR ...
>   GROUP BY subj_id;
>
> executes in 20seconds here.
>
> On the other hand:
> SELECT subj_id, max(timestamp) FROM event_view WHERE subj_id IN
>   (SELECT id
>      FROM uri
>      WHERE (((value = 'application://gedit.desktop')
>              OR (value = 'application://devhelp.desktop')
>              OR (value = 'application://google-chrome.desktop') OR ...)
>   GROUP BY subj_id;
>
> executes immediately. Of course results are equivalent.
>
> --
> You received this bug notification because you are subscribed to The
> Zeitgeist Project.
> https://bugs.launchpad.net/bugs/844877
>
> Title:
>  Query execution slow
>
> Status in Zeitgeist Framework:
>  New
>
> Bug description:
>  Synapse is using various not-so-complex find_events queries to display
>  recent activities, and it seems that especially a query for "All"
>  category is taking much longer than any other query (~750ms with a DB
>  with 200k events).
>
>  Here's the output from zg with the debug_sql extension:
>
>  [DEBUG - root] # parameters: {'event_templates':
> [Event([dbus.Array([dbus.String(u''), '1315492708863', dbus.String(u''),
> dbus.String(u''), dbus.String(u''), ''], signature=dbus.Signature('s')),
> [Subject([dbus.String(u''), dbus.String(u''), dbus.String(u''),
> dbus.String(u''), dbus.String(u''), dbus.String(u''), dbus.String(u''),
> dbus.String(u'')]), Subject([dbus.String(u''), dbus.String(u'!
> http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Folder'),
> dbus.String(u''), dbus.String(u''), dbus.String(u''), dbus.String(u''),
> dbus.String(u''), dbus.String(u'')]), Subject([dbus.String(u''),
> dbus.String(u'!
> http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Software'),
> dbus.String(u''), dbus.String(u''), dbus.String(u''), dbus.String(u''),
> dbus.String(u''), dbus.String(u'')])], dbus.Array([],
> signature=dbus.Signature('y'))])],
>   'max_events': dbus.UInt32(96L),
>   'order': dbus.UInt32(2L),
>   'return_mode': 1,
>   'self': <_zeitgeist.engine.main.ZeitgeistEngine instance at 0x1b66248>,
>   'sender': ':1.3604',
>   'storage_state': dbus.UInt32(2L),
>   'time_range': [1300977508860, 9223372036854775807]}
>
>  [DEBUG - root] # database size: {'actor': 129,
>   'event': 192746,
>   'interpretation': 68,
>   'manifestation': 27,
>   'mimetype': 353,
>   'uri': 60265}
>  [DEBUG - root] # BEGIN SQL QUERY #
>  no pretty sql: SELECT id FROM event_view
>                                NATURAL JOIN (
>                                        SELECT subj_id,
>                                                max(timestamp) AS timestamp
>
>                                        FROM event_view  WHERE (+timestamp
> >= ? AND ((NOT (subj_interpretation = ?) AND NOT (subj_interpretation = ? OR
> subj_interpretation = ? OR subj_interpretation = ?))))
>                                        GROUP BY subj_id)
>                                GROUP BY subj_id
>                                ORDER BY  timestamp DESC
>                                 LIMIT 96 : [1300977508860, 45, 46, 47, 43]
>  took 0.712120s
>  # END SQL QUERY
>  [DEBUG - zeitgeist.engine] Found 96 events IDs in 0.723284s
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/zeitgeist/+bug/844877/+subscriptions
>