Is there a reason you can't share one $dbh for all children? (I think this is possible with Parallel::ForkManager.)
No, it is not possible.
Reason: Think of two childs, both want to make a query:
# Child 1:
SELECT * FROM foobar WHERE baz = 3
# Child 2:
SELECT grzbaka FROM baz WHERE foo = 5
Now, both send their queries at the same time. The db server might receive:
SELECT * FROSELECT grzbaka FROM baM foobar WHERE baz = 3z WHERE foo = 5
Of course, reality is more complex, this example is just meant as a simple explanation why one db connection used by many childs don't work (as expected).
BTW, if you do cooperative multitasking, like POE does, everything is ok -- there is only one process which sends data to the db server.
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