Large CRLs present a challenge both to issue and to validate.

RFC 3280 allows the partitioning of CRLs by "scope" (§5 - CRL and CRL Extensions Profile):

«[...]
Each CRL has a particular scope. The CRL scope is the set of
certificates that could appear on a given CRL. For example, the
scope could be "all certificates issued by CA X", "all CA
certificates issued by CA X", "all certificates issued by CA X that
have been revoked for reasons of key compromise and CA compromise",
or could be a set of certificates based on arbitrary local
information, such as "all certificates issued to the NIST employees
located in Boulder".
[...]»

A very nice and useful feature to deal with large CRLs would be to allow the definition of a such a scope by which certificate profile the certificate was issued under.
A matching between the Issuing CA and CDP, based on certificate profile must be done.

It is important to notice that a certificate can not move around partitions during its lifetime.