My English is not perfect, surely :>)
I'v mentioned "other conception", because necessity of deadlock daemon, for instance. In _my_ point of view it is up to developer to manage that deadlocks, sql machines behave in more standard way and they do it without additional effort. Aditionally, I know table-locking and row-locking in sql, but no page-locking.
Ad "shared memory" - if you have two sepparated processes, using BerkeleyDB, there is no easy chance to share some memory with loaded data between those processes. Oppositely, when you have two sepparate processes using two connections into sql database, the sql machine can use shared memory to satisfy both connections (querying the same, of course).

In reply to Re^4: Perl Hash vs BerkeleyDB vs MySQL by pajout
in thread Perl's Hash vs BerkeleyDB vs MySQL by monkfan

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