Truncating a large database failed

Question

if (0 != dbp->truncate(dbp, NULL, &countp, 0)){
out_string(c, "ERROR");
}else{
out_string(c, "OK");
If only a few records in database, it works. But when millions of records, it fails.
Is there a need to set following three parameters?
DB_ENV->set_lk_max_lockers     Set maximum number of lockers
DB_ENV->set_lk_max_locks     Set maximum number of locks
DB_ENV->set_lk_max_objects     Set maximum number of lock objects
Regards
Steve Chu

Answer 1

Hi Steve,
It's highly likely that you haven't configured the locking subsystem properly. Locking is involved indeed when truncating a database that is part of an environment with the locking subsystem initialized. For each database page a lock is needed; so if you know the size of your database and the page size you can estimate how many locks you will need (you can also use the "db_stat" utility to find out this information). The default values for the maximum number of locks, lockers and lock objects is 1000, which may be insufficient in the context of your large database.
Information on how to configure the locking subsystem is here:
http://you've-db/db/ref/lock/max.html
Also, I would suggest testing the value returned by DB->truncate() and printing out the eventual error using the error reporting means you'e configured.
Regards,
Andrei