Table locking during a load operation

The dbload -k option overrides the default table lock mode during the load operation. The -k option instructs dbload to lock the tables in exclusive mode rather than shared mode.

If you do not specify the -k option, the tables specified in the command file are locked in shared mode. When tables are locked in shared mode, the database server still must acquire exclusive row or page locks when it inserts rows into the table.

When you specify the -k option, the database server places an exclusive lock on the entire table. The -k option increases performance for large loads because the database server does not need to acquire exclusive locks on rows or pages as it inserts rows during the load operation.

If you do not specify the -r option, the tables specified in the command file are locked during loading so that other users cannot update data in the table. Table locking reduces the number of locks needed during the load but reduces concurrency. If you are planning to load a large number of rows, use table locking and load during nonpeak hours.