Hello, Roman,

> Hi,

>> If I correctly understood, it may be better to disable autocommit.

> In general - yes.

>> So, when I'm querying a huge datbase with a SELECT statement that
>> returns hundred of thousand rows, when to do the commit? Between
>> each row retrivial and after a heuristic and prefined number (10,
>> 100, 1000...)? What is the best practice?

> Why do you need to do commit at all? For read-only selects you do not
> need to do commits. Firebird is an RDBMS with optimistic concurrency,
> this means that readers do not block writers. So, as long as you do
> not modify the row you will not get any lock conflict there.

But you need to have transaction that is explicitly read-committed and
isc_tpb_read - read-only (in this case transaction is started as pre-committed
and may not be committed without impact on the engine) ! Otherwise you are
going to inhibit garbage collection and may loose performance.



Nickolay Samofatov