Return all entries in Client without modify 'sizelimit' of slapd.conf

[Phillip <phuang@plasmon.cn>]

Hello,All,

In slad.conf file of OpenLDAP, the "sizelimit" directive specifies the
number of entries to return to a search request. "-1" means unlimited.
My case is, I have 20000 entries on the LDAP server, if use the default
sizelimit setting, 500, how to return all the 20000 entries by issuing
"ldapsearch -x" in client machine? 

I tried to split 20000 entries to pages by filter, and I'm troubled
because I do not know which attribute would be the best choose, and I
found the search filter operators,(>=, <=) compare the attribute based
on their strings, not number, for example, 20 >= 1200.

Please give me some advices.

Thanks and Regards,
Phillip.