big delete, big performance drop

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

I had stuffed my directory with a bunch of test data that I've now cleaned out
with a massive ldapdelete (killing 1 million entries).  I noticed two things
today:

1) The id2entry.bdb database didn't change in size, remaining at 1.2GB.  After a
slapcat/delete everything/slapadd, that file's 4.3MB.
2) Search performance was terrible, taking about 8 seconds to pull down the
remaining ~300 objects in the directory.  After a slapcat/delete
everything/slapadd, things are back to normal and performing as they were before. 
Relatively speaking, the directory performed much better before the delete, only
taking about a minute to ldapsearch every entry in it.

Here's my DB_CONFIG:

set_cachesize           3 0 1
set_lg_regionmax        262144
set_lg_bsize            2097152
set_lg_dir              /usr/local/var/openldap-data
set_tmp_dir             /tmp
set_flags       DB_LOG_AUTOREMOVE

(The box has 8GB of RAM.  In my slapd.conf, cachesize = 50000 and
idlcachesize=20000.)

Is there anything in general that could cause this behavior that I could look for?
 I don't plan on doing these wholesale add/delete ops all the time, but it
wouldn't be uncommon in the future to have to delete, say, 60,000 objects to pull
a semester of students, for example.

Thanks,
  John



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