[Info-ingres] Weird problem in Ingres 10

[Mark]

On Tue, 15 May 2018 16:41:17 +0100, Mark
<i at dontgetlotsofspamanymore.net> wrote:

>We have C code using embedded SQL to access Ingres databases.  The
>relevant code has been working for a long time.  Recently we have
>experienced occasions where the first time an INSERT or UPDATE
>statement is executed the data is not inserted or updated, but no
>errors are reported.  Subsequent cases where the same code is excuted
>work fine.  This problem has only occurred on Ingres 10 databases on
>Linux and the same code with Ingres 9 works fine.

Again, thanks to all who replied to this post :-)

The problems are now solved with the help of Actian Tech support.

For anyone who is interested the solutions were:

- For the update: Change the following parameter in config.dat:
ii.<host>.dbms.*.system_lock_level:      default

Apparently it was set to mvcc by default which seemed to cause the
update statement to see an out of date version of the table.

- For the insert: There was a second table in the same transaction
with the incorrect schema and prevented the insert working in the
first table.

Correcting the schema fixed the problem.

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