Justin Clift writes:
> Lee Kindness wrote:
> > WITH ON_DUPLICATE = CONTINUE|TERMINATE (or similar)
> I would suggest :
> WITH ON_DUPLICATE = IGNORE|TERMINATE
> purely for easier understanding, given there is no present standard nor
> other databases' syntax to conform to.
Personally I don't see the need, and think that 'COPY FROM' could well
just go with the new semantics...
Onto an implementation issue - _bt_check_unique() returns a
TransactionId, my plans were to return NullTransactionId on a
duplicate key but naturally this is used in the success
scenario. Looking in backend/transam/transam.c I see:
TransactionId NullTransactionId = (TransactionId) 0;
TransactionId AmiTransactionId = (TransactionId) 512;
TransactionId FirstTransactionId = (TransactionId) 514;
From this I'd gather <514 can be used as magic-values/constants, So
would I be safe doing:
TransactionId XXXXTransactionId = (TransactionId) 1;
and return XXXXTransactionId from _bt_check_unique() back to
_bt_do_insert()? Naturally XXXX is something meaningful. I presume all
I need to know is if 'xwait' in _bt_check_unique() is ever '1'...
Lee Kindness, Senior Software Engineer
Concept Systems Limited.
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