Ralf Haferkamp writes:
Am Donnerstag 11 Dezember 2008 16:39:24 schrieb Andrzej Jan Taramina:
That makes no sense. Checking to see if there are entries that depend on the schema before attempting the delete and declining the delete if there are such entries makes sense.
But is very time consuming and resource intensive. E.g. checking for the presence of an AttributeType requires a full scan of the database if that AttributeType is not indexed, I think.
An index would be insufficient for such a check, because a schema element can be part of an attribute value. The DN and "Name and Optional UID" syntaxes contain attribute types. Guide/Enhanced Guide contain object classes (as does objectClass itself of course). OID contains either.
The schema attributes themselves must be checked, and inheritance. Also configuration, both config known to slapd like access control and that known to modules like the attributes restricted by the "unique" overlay.
Or much of the latter could be dropped, in favor of a reference count or garbage collection. But either way, modules must provide a way to ask them if they are using a schema element.
A blanket refusal to do such a delete is inappropriate, IMO.
But the safest option we can currently offer, IMO.
Could add a "trust me, I know what I'm doing" control. slapd only accepts potentially fatal cn=config changes if that control is set.