IDL cache and a mix of index/unindexed attrs in a query

[Quanah Gibson-Mount <quanah@zimbra.com>]

I'm never 100% sure I understand how the idl cache works, but as I 
understand it, it caches the index keys of common searches, where the 
attributes are indexed.  Assuming my understanding is correct, my question 
has to do with how things behave when some of the attributes are indexed, 
and some aren't.  For example, assume:

a - indexed eq, a match only returns a single entry in the DB
b - unindexed, only has one possible value if present
c - unindexed, only has one possible value if present

A query of (&(a=x)(b=y)(c=z)) performs very quickly because the a=x filter 
is applied first, and locates the object, with the remaining pieces of the 
filter being applied to the entry that was found.  My question is, does 
this query end up in the IDL cache?

I played around with this somewhat, and I see no difference in search times 
between:

(a=x)
(&(a=x)(b=y))
(&(a=x)(by=y)(c=z))

In this usage case, then, is there really any benefit to indexing b & c?

--Quanah

--
Quanah Gibson-Mount
Principal Software Engineer
Zimbra, Inc
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