Subject Re: [firebird-support] Synchronisation between two processes
Author Bryan Cole
Post date 2014-07-13T07:36:18Z
I'm not Sure what isolation level I'm using. Whatever is default I expect. I'm using an ORM and python interface. I will need to dig into this a little deeper. However, my transaction do not overlap, so I don't expect the isolation level to matter.

Regarding using the embedded interface from more than one process: I thought this was ok for firebird versions 2.5 and later. The docs indicate full SMP operation is supported using direct file access. If I'm mistaken then this might be the root of my problem. 

Thanks
BC


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-------- Original message --------
From: "Ann Harrison aharrison@... [firebird-support]" <firebird-support@yahoogroups.com>
Date: 12/07/2014 14:46 (GMT+00:00)
To: firebird-support@yahoogroups.com
Subject: Re: [firebird-support] Synchronisation between two processes


 

Sorry, from my phone, sobad formatting and terse.  What transaction isolation mode(s) are you using?  Ordinarily direct file access is limited to one process. What version of Firebird?

Ann

On Jul 11, 2014, at 10:31 AM, "Bryan Cole bryan.cole@... [firebird-support]" <firebird-support@yahoogroups.com> wrote:

Hi,

I have two client processes (on uptodate linux host) accessing a firebird database using the direct-file-access method (libfbembed.so). Most of the time, when a write transaction is committed in one process the data is visible in the second process more-or-less immediately. Sometimes (apparently depending on the order of DB access, size of the table and phase of the moon), it takes much much longer (>14 seconds) for changes to show up in the second process. Is there a method to ensure that the results of a transaction are immediately available to other processes?

I'm using firebird-2.5.2, superclassic server on linux (Fedora20). All DB writes/reads are within the context of a transaction.

Thanks,

BC

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