So I've got this transaction which tries to create records in a table
and gets
"violation of PRIMARY or UNIQUE KEY constrain"
There are, I believe, no records in the table /visible to the same
transaction/ with the same primary key, as the insertion code checks
first, and doesn't attempt to insert a record that's already there.
Now, I seem to recall seeing somewhere that actually a primary key (and
any other unique index?) is independent of transactions, so the following:
(1) Transaction A inserts record X
(2) Transaction B attempts to insert record X (having first checked that
it doesn't exist, which it doesn't as far as transaction B is concerned,
because transaction A hasn't committed yet)
results in the error.
Have I remembered this behaviour of primary keys correctly? Please could
someone remind me where the documentation is if so?
--
Tim Ward
