New ASFLAG.SBR flag: AF_ISAMNODUPERRS (&h8000) modifies the behavior of the ISAM-A CREATE'RECORD statement. Normally, if the record already exists (and duplicates not allowed), it returns Basic error 208 (attempt to add duplicate key). With the AF_ISAMNODUPERRS flag set, CREATE'RECORD will instead just return FSTAT=2 but no Basic error. The motivation is mainly to improve performance of certain specialized file build operations where you want to add a record if it doesn't exist but do nothing if the record does exist. Setting the flag allows the program to eliminate a FIND operation prior to each CREATE'RECORD, which may significantly increase the build speed.
