Re: substring index oddity

["John Madden" <jmadden@ivytech.edu>]

> No. Nothing about LDBM has any relevance to back-bdb.

Good to hear. :)

> As already noted, by default a substring term must have at least 4
> characters in order for indexing to have any effect.

> subinitial and subfinal default to a minimum of two characters, so this
> search didn't use the index either.

Good.  More testing shows much better results in light of that info and I can
probably live with that design.  However, I'm still seeing a bad case:

uid=test2222* : 28 seconds
# numEntries: 111
uid=test22222* : 28 seconds
# numEntries: 11

Bad, even though there are more than 4 chars in the string.  Yet:

uid=test*2222 : 0.007 seconds
# numEntries: 100
uid=*est222* : 0.048s
# numEntries: 1111

Quite good.


John




-- 
John Madden
UNIX Systems Engineer
Ivy Tech Community College of Indiana
jmadden@ivytech.edu