[Zope-CMF] Optimizing catalog queries

[Seb Bacon]

Gitte Wange wrote:
>>You should always see an improvement using DateIndexes or
>>DateRangeIndexes over FieldIndexes.  Don't forget to change effective,
>>expires, modified etc into DateRangeIndexes too.
> 
> 
> They should be DateRangeIndexes ?

Sorry, DateIndexes.

>>DateRangeIndex is for things which should be between two dates, e.g.
>>time 'A' where 'effective' < 'A' < 'expires'; google for examples.
> 
> I have googled and found a lot of hits but nothing that really explained it - 
> will try again.

for an index 'isEffective' you might put a 'start' field of 'effective' 
and an 'end' field of 'expires'.  You then don't need to do the 'range' 
stuff in your isEffective=DateTime() query.  However, in your case you 
probably want to keep individual 'effective' and 'expires' indexes for 
backwards compatibility or other application-specific reasons.  These 
should be DateIndexes.

In fact I've never used DateRangeIndexes like this so someone else may 
correct me, but this is my understanding.

Seb