zeitgeist team mailing list archive

[Markus Korn <thekorn@xxxxxx>]

** Changed in: zeitgeist
     Assignee: (unassigned) => Markus Korn (thekorn)

** Changed in: zeitgeist
       Status: New => In Progress

-- 
ZeitgeistEngine.__init__(): statement to get last row id is not using the index
https://bugs.launchpad.net/bugs/641100
You received this bug notification because you are a member of Zeitgeist
Framework Team, which is subscribed to Zeitgeist Framework.

Status in Zeitgeist Framework: In Progress

Bug description:
The attached script is  creating a log with ~49k events.
In the constructor of ZeitgeistEngine we need to search for the minimum and maximum event id. In the script I'm doing two different ways of getting these values:

Our current query:
SELECT MIN(id), MAX(id) FROM event
-> this is not using the event index, and takes about 0.096 secunds for me

do the same in two queries:
SELECT MIN(id) FROM event    +    SELECT MAX(id) FROM event
-> both queries are using the index, and together they take about 0.003 for me

I suggest changing the one query into two to get some speedups.