Subject Re: Memory usage and long running transactions
Author joaquin_ifa
--- In, Pavel Menshchikov
<developer@l...> wrote:
> Hello Joaquin,
> j> I have seen in some documents that long running transactions may
> j> create performance problems and high VM usage. The statistics of
> j> dbs seems ok (small diference between oldest tr and oldest
> j> However in some parts of our UI we show a grid showing data and
> j> transaction used is active for the time that window is open. I
> j> seen that IB 7.1 has an option for
> j> long-running-read-only-transactions
> j> that do not impact on performance. Is this available in Firebird
1.5 ?
> j> What parameters should be used ? (I use FIB and Firebird 1.5...).
> With FIB you specify two transactions for datasets: "ordinary"
> transaction (which may be writing as well, but, AFAIK, is used for
> reading data), and a separate "writing" transaction. So, you
> those transactions too: make long-lasting reading transaction with
> parameters
> read
> read_committed
> rec_version
> nowait
> and short-lasting writing transaction
> write
> concurrency
> nowait
> --
> Best regards,
> Pavel Menshchikov

Ok, thanks for the information.

I now use the transaction that feeds the grid with the read parameter.
Of course we use all other transaction as needed in small time slots.

Is this the same option as the "new" read-only transaction in IB 7.1 ?
They say that they have a special read-only transaction that does not
impact on performance. Don't understand exactly the mecanism of the
transactions but it seems that with their special read-only
transactions there is no need for lots of internal management and that
results in better performance.