[Zeitgeist] [Bug 691167] Re: The payload is sometimes mentioned as string and sometimes as array of bytes
** Changed in: zeitgeist Milestone: 0.7.0 = None -- You received this bug notification because you are a member of Zeitgeist Framework Team, which is subscribed to Zeitgeist Framework. https://bugs.launchpad.net/bugs/691167 Title: The payload is sometimes mentioned as string and sometimes as array of bytes Status in Zeitgeist Framework: In Progress Bug description: In the event serialization format, the third array is array of bytes or ay as dbus signature. When an event enters an extension, it looks like Event([dbus.Array([u'', u'1292500628312', u'', u'', u'application://foo.desktop'], signature=dbus.Signature('s')), [Subject([u'', u'', u'', u'', u'', u'', u''])], dbus.Array([], signature=dbus.Signature('y'))]) which implies that payload is array of bytes Now look at _zeitgeist/engine/datamodel.py at line 58 where you get the line popo.append(str(ev[2])) Really so when you do str() on dbus.Array([], signature=dbus.Signature('y')) you get dbus.Array([], signature=dbus.Signature('y')) instead of the contents of bytes converted to string Now when you call Event.get_plain on Event([dbus.Array([u'', u'1292500628312', u'', u'', u'application://foo.desktop'], signature=dbus.Signature('s')), [Subject([u'', u'', u'', u'', u'', u'', u''])], dbus.Array([], signature=dbus.Signature('y'))]) you get [[u'', u'1292500628312', u'', u'', u'application://foo.desktop'], [[u'', u'', u'', u'', u'', u'', u'']], dbus.Array([], signature=dbus.Signature('y'))] Not what you expect ___ Mailing list: https://launchpad.net/~zeitgeist Post to : zeitgeist@lists.launchpad.net Unsubscribe : https://launchpad.net/~zeitgeist More help : https://help.launchpad.net/ListHelp
[Zeitgeist] [Bug 632363] Re: Slow queries: SQL indexes not used
** Changed in: zeitgeist Milestone: 0.7.0 = None -- You received this bug notification because you are a member of Zeitgeist Framework Team, which is subscribed to Zeitgeist Framework. https://bugs.launchpad.net/bugs/632363 Title: Slow queries: SQL indexes not used Status in Zeitgeist Framework: Confirmed Bug description: THE PROBLEM: I am seeing query times around 200ms (and 150ms with my latest performance tweak in trunk), which surprised me as quite slow since my queries where quite simple. I had expected times around 1-2ms. Reading up on the sqlite documentation I see that the queries we generate are pretty far from optimized in an sqlite world [1]. The case is that when ever you use an OR sqlite will no longer use an index. Thus this query is NOT using the indexes: SELECT * FROM event WHERE interpretation=1 OR interpretation=2 But if we rewrite it using IN instead the indexes will be used: SELECT * FROM event WHERE interpretation IN (1, 2) This also explains the case where Michal where seeing tremendously slow query times when searching for a big range of mimetypes. Looking in _zeitgeist.engine.sql.WhereClause.add_text_condition() I am also pretty sure we are not using the indexes for prefix queries (eg file://home/*). THE SOLUTION I *definitely* don't think we should panic and feverishly start rewriting our query compilation. Here's what I propose: 1) Implement an envvar ZEITGEIST_DEBUG_QUERY_PLANS which will spit out all our SQL calls and the query plans for each of our calls. The query plan will tell us how the db is queried and which indexes are used if any. The query plan is obtained by prefixing the SQL statement with EXPLAIN QUERY PLAN. 2) Collect some useful intelligence with this new tool, and generally learn more about how we can optimize sqlite queries. A big question here is how the event_view VIEW impacts the query plan. 3) Write a new template - SQL compilation engine that generates SQL optimized for sqlite. We can actually be quite clever about grouping our OR statements into IN clauses - but it will be tricky to get right. NOTE: That this doesn't imply any change in the public API or event template system. That would be the wrong solution imho. Our current API is nice and simple by my standards. Let's keep it that way. [1]: See fx the section Using Indexes To Speed Searching in http://www.sqlite.org/vdbe.html ___ Mailing list: https://launchpad.net/~zeitgeist Post to : zeitgeist@lists.launchpad.net Unsubscribe : https://launchpad.net/~zeitgeist More help : https://help.launchpad.net/ListHelp
[Zeitgeist] [Bug 686732] Re: add cache to get events
** Changed in: zeitgeist Status: In Progress = Fix Committed -- You received this bug notification because you are a member of Zeitgeist Framework Team, which is subscribed to Zeitgeist Framework. https://bugs.launchpad.net/bugs/686732 Title: add cache to get events Status in Zeitgeist Framework: Fix Committed Bug description: Sometimes the same events get requested by several different apps. having a cache for the get_events cache can cut off some time, and enhance performance. ___ Mailing list: https://launchpad.net/~zeitgeist Post to : zeitgeist@lists.launchpad.net Unsubscribe : https://launchpad.net/~zeitgeist More help : https://help.launchpad.net/ListHelp