[Info-ingres] Weird problem in Ingres 10

Thu May 17 12:51:20 UTC 2018

On Thu, 17 May 2018 12:35:38 +0000, Martin Bowes
<martin.bowes at ndph.ox.ac.uk> wrote:

>Going out on a limb here...
>
>Are we sure the two sessions are working on the same table owned by the same user in the same database as each other?

I am only using a single session for this.

>In the sc930 trace file can you find the connection information immediately prior to the update code. You are looking for a line like:
>BEG 27/03/2018 13:26:07.598545, Database: iidbdb, User: ingres

There's nothing like this in the trace files.

>You could also check your database and see if there are any duplicates of the table with the query:
>Select table_owner from iitables where table_name='YOURTABLE';
>
>Do that for each table involved in the update.

Only 1 row (& only 1 table in the update).

>Marty
>
>-----Original Message-----
>From: Mark [mailto:i at dontgetlotsofspamanymore.net] 
>Sent: 17 May 2018 13:21
>To: info-ingres at lists.planetingres.org
>Subject: Re: [Info-ingres] Weird problem in Ingres 10
>
>On Thu, 17 May 2018 12:06:48 +0000, Martin Bowes
><martin.bowes at ndph.ox.ac.uk> wrote:
>
>>No error code and with a rowcount of zero means the update is successful, but had no work to do.
>>
>>I presume there is a where clause in the update and that it looks OK.
>
>There is a where clause and it does match a record so there is "work
>to do".
>
>>Can you compare the code which worked and the code which didn't work for discrepancies?
>
>Yes.  They are exactly the same!  And it only fails the first time it
>is executed, all other times work fine.
>
>>Marty
>>
>>-----Original Message-----
>>From: Mark [mailto:i at dontgetlotsofspamanymore.net] 
>>Sent: 17 May 2018 12:57
>>To: info-ingres at lists.planetingres.org
>>Subject: Re: [Info-ingres] Weird problem in Ingres 10
>>
>>On Thu, 17 May 2018 11:21:37 +0000, Martin Bowes
>><martin.bowes at ndph.ox.ac.uk> wrote:
>>
>>>Twice...
>>>
>>>Once where it updates the data and once where it puts it back the way it was?
>>
>>No.  The data is the same for each.
>>
>>>What do the Rowcount figures say on each statement?
>>
>>0.
>>
>>>Marty
>>>
>>>-----Original Message-----
>>>From: Mark [mailto:i at dontgetlotsofspamanymore.net] 
>>>Sent: 17 May 2018 12:12
>>>To: info-ingres at lists.planetingres.org
>>>Subject: Re: [Info-ingres] Weird problem in Ingres 10
>>>
>>>On Wed, 16 May 2018 12:40:48 -0400, Karl and Betty Schendel
>>><schendel at kbcomputer.com> wrote:
>>>
>>>>SC930 tracing is server wide and runs until you stop it with set notrace sc930.
>>>>So you can connect to any database, do the set trace record '/some/ingres-writable/dir'
>>>>and the set trace point sc930, go to the trace record directory you gave it and
>>>>ensure that there's at least something there (should be one or more sessNNNNN files),
>>>>and then you can run your esql program until the fault happens.
>>>>
>>>>You don't actually need to put the sc930 into the esql program unless you want to
>>>>do it that way.
>>>>
>>>>Once you capture what you need to capture, set notrace point sc930 turns it off.
>>>>
>>>>You'll need the trace point privilege, simplest is to do it as the installation owner
>>>>(user ingres, traditionally).
>>>
>>>Thanks again.  We now have traces but they don't help me.  The traces
>>>include the SQL statement and the data but, pretty much, nothing else.
>>>
>>>The only notable thing I observed is that the data is traced twice for
>>>the failed transaction and only once for the successful ones.
>>>
>>>There are no error messages.
>>>
>>>>Karl
>>>>
>>>>> On May 16, 2018, at 11:12 AM, Mark <i at dontgetlotsofspamanymore.net> wrote:
>>>>> 
>>>>> On Wed, 16 May 2018 12:11:08 +0000, Martin Bowes
>>>>> <martin.bowes at ndph.ox.ac.uk> wrote:
>>>>> 
>>>>>> Just to expand on Karl's sc930...You may already know this...
>>>>>> 
>>>>>> To turn it on, make a recording directory...mkdir /full/path/to/directory'
>>>>>> 
>>>>>> And then...
>>>>>> sql iidbdb << SQL_END
>>>>>> set trace record '/full/path/to/directory';
>>>>>> set trace point sc930 1;
>>>>>> \p\g
>>>>>> \q
>>>>>> SQL_END
>>>>> 
>>>>> Do I need to run this on the server account?  I have implemented it
>>>>> currently in the embedded SQL of my program.
>>>>> 
>>>>>> FYI. The digit after the sc930 indicates a tracing level, 1 should be sufficient.
>>>>>> 
>>>>>> Run the errant query.
>>>>>> 
>>>>>> And turn off the sc930.
>>>>>> sql iidbdb << SQL_END
>>>>>> set trace point sc930 0;
>>>>>> \p\g
>>>>>> \q
>>>>>> SQL_END
>>>>>> 
>>>>>> You can now access the recording directory and start scanning the files for any sign of life from your query.
>>>>>> 
>>>>>> Marty
>>>>>> 
>>>>>> -----Original Message-----
>>>>>> From: Karl and Betty Schendel [mailto:schendel at kbcomputer.com] 
>>>>>> Sent: 16 May 2018 12:54
>>>>>> To: Ingres and related product discussion forum
>>>>>> Subject: Re: [Info-ingres] Weird problem in Ingres 10
>>>>>> 
>>>>>> On May 16, 2018, at 7:44 AM, Mark <i at dontgetlotsofspamanymore.net> wrote:
>>>>>>> 
>>>>>>> On Tue, 15 May 2018 12:27:09 -0400, Karl and Betty Schendel
>>>>>>> <schendel at kbcomputer.com> wrote:
>>>>>>> 
>>>>>>>> It's certainly not something I have heard of or seen before.  Do you have any rules
>>>>>>>> defined on the relevant tables?  Try enabling LOG_TRACE if the problem is
>>>>>>>> sufficiently predictable, or do a logdump after the problem occurs if it's not;
>>>>>>>> the idea being to try to see whether you actually got any PUT (insert) or
>>>>>>>> REP (replace) log records that were then rolled back, or whether the insert / update
>>>>>>>> was never executed at all.
>>>>>>> 
>>>>>>> After enabling log_trace all I got was:
>>>>>>> 
>>>>>>>   LOG: SAVEPOINT   Size written/reserved:      0/     0  Flags:
>>>>>>> -------------------------------------------------------------------
>>>>>> 
>>>>>> So the insert/update isn't ever being executed.  Either it's failing with some sort of
>>>>>> silent error, which would seem odd, or it's not reaching the backend at all, or
>>>>>> it's being pre-empted by a before rule.  I think the next step would be to enable
>>>>>> sc930 tracing and see if the backend is getting the insert-update, and what
>>>>>> end-of-query status it's recording.  There should be KB articles on enabling
>>>>>> SC930 tracing.
>>>>>> 
>>>>>> Karl
>>>>>> 
>>>>>> _______________________________________________
>>>>>> Info-ingres mailing list
>>>>>> Info-ingres at lists.planetingres.org
>>>>>> http://lists.planetingres.org/mailman/listinfo/info-ingres
>>>>> 
>>>>> -- 
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