Shared row locks?

The 7.2 Server concepts guide asserts that row locks are always exclusive (top of page 10-11).

However, I have seen the lock monitor show a session waiting of a lock of type TX and mode S, i.e. a *shared* row lock.

The session is question was blocked in foreign key processing while deleting a master row. The only reference to the row was from a detail row which had been inserted but not yet committed. The master row delete was apparently waiting for a shared row lock on the uncommitted detail record.

Does anyone know where I can find out more about shared row locks? Is it possible to request one explicitly?

I am using server version 7.2.3.0.0 under Solaris 2.4.

Charles Jardine - University of Cambridge (UK) Computing Service Received on Thu Dec 12 1996 - 00:00:00 CST