The constant is BDB_IDL_LOGN in back-bdb/idl.h. Incrementing it by 1 will double the range of an index slot before it loses precision. It will also double the amount of memory used by all of the indexing functions. I think you can safely double the current value without overrunning the default thread stack size. But if you go even higher you'll probably need to increase it.
The current value for LDAP_PVT_THREAD_STACK_SIZE is (1 * 1024 * 1024 * sizeof(void *))
(4MB on a 32 bit machine, 8MB on 64 bit machine).
If you need to raise it I would suggest adding e.g. XDEF=-DLDAP_PVT_THREAD_STACK_SIZE=16777216 to your make invocation and recompiling libldap_r with this new value.
Hello,
I'm very happy! I've say thanks to all who helped me - especially Howard and Quanah. I changed the BDB_IDL_LOGN up to 17 and now the slapd is running very fast. The time for the search now is more then 100 times faster. Additionally, my hard disk isn't stressed anymore because of using shared memory (shm_key).
Kindly regards
Steeg