Subject Re: [firebird-support] Problem with "Unsuccessful execution caused by a system error that precludes successful execution of subsequent statements"
Author Harriv
The application is done with Delphi XE 2using UIB library for Firebird connection. Running on Windows 7, 64bit, Firebird 2.5.3 SuperServer. Application is still 32 bit however.

On Fri, Oct 10, 2014 at 1:53 PM, Mark Rotteveel mark@... [firebird-support] <> wrote:

On Fri, 10 Oct 2014 12:43:42 +0300, "Harriv harriv@...
[firebird-support]" <> wrote:
> My application generates following errors occasionally:
> Error writing data to the connection.
> Unsuccessful execution caused by a system error that precludes
> execution of subsequent statements
> GDS Code: 335544727 Error Code: 407
> And:
> GDS Code: 335544726 Error Code: 406
> And sometimes:
> GDS Code: 335544332 Error Code: 12
> These come from simple select -statement, which is executed pretty often
> (every few seconds).
> What could cause this problem? According to error code list this e
> connection problem, but Firebird log doesn't show extra disconnects.
> Is this caused by the client side or does this come from server? Can
> root cause be in another application accessing the database or is it the
> same application where the error occurs? The system has about 5 active
> applications accessing the database all the time.
> Is there any way to debug this from server side?
> Earlier I had similar problems when using same connection from multiple
> threads, but that should be fixed.

335544726=Error reading data from the connection.
335544727=Error writing data to the connection.

These are usually thrown for network related errors, which are normally
only client-side AFAIK. Without more information (eg platform, connection
library, etc) it is hard to provide more help.

335544332=invalid transaction handle (expecting explicit transaction

Means that you (or the access component) are handling transactions
incorrectly. Make sure that you don't concurrently use **the same**
connection from **multiple** threads.

None of these error have to do with concurrent access by other
applications or other connections.