Special thanks to Rich for his reviews and comments. I introduced slapi_modify_internal_set_pb_ext to pass Slapi_DN which reduces the unnecessary Slapi_DN generation and DN normalization. (The attached patch is gzip'ed.) Thanks, --noriko Reduce the number of DN normalization . Adding SLAPI_TARGET_SDN as well as its macros, SLAPI_SEARCH_TARGET_ SDN SLAPI_ADD_TARGET_SDN, SLAPI_MODIFY_TARGET_SDN, etc. . Adding SLAPI_MODRDN_NEWSUPERIOR_SDN. . SLAPI_TARGET_DN and SLAPI_MODRDN_NEWSUPERIOR are kept for the back- ward compatibility. But they are marked as deprecated. They are pointing dn in SLAPI_TARGET_SDN and SLAPI_MODRDN_NEWSUPERIOR_SDN, respectively. . slapi_pblock_set(.., SLAPI_TARGET_DN/SLAPI_MODRDN_NEWSUPERIOR, dn) takes dn string and reset Slapi_DN to SLAPI_TARGET_SDN/SLAPI_MODRDN_ NEWSUPERIOR_SDN. . slapi_pblock_get(.., SLAPI_TARGET_DN/SLAPI_MODRDN_NEWSUPERIOR, &dn) retrieves dn out of SLAPI_TARGET_SDN/SLAPI_MODRDN_NEWSUPERIOR_SDN. . Replacing slapi_dn_normalization_ext call with generating Slapi_DN APIs (e.g., slapi_sdn_new_dn_...) as much as possible and stash it in pblock using SLAPI_TARGET_SDN. . When a normalized DN string is needed, get it using slapi_sdn_get_[n]dn from the stashed Slapi_DN. . Introduced a new field to Slapi_DN. "udn" for the original DN; "dn" is a normalized DN; "ndn" is a case- ignored normalized DN. Taking advantage of the knowledge of the stage of the DN, call the most efficient DN creating API (e.g., slapi_sdn_new_dn_... vs. slapi_sdn_new_normdn_... vs. slapi_sdn_new_ndn_...) Others . Replacing inefficient array assignment with memset (acl.c) and memcpy (idl_common.c). . Fixing invalid memory access in LASDnsBuild (lib/libaccess/lasdns.cpp). . Fixing compiler warnings.