[Info-ingres] Weird problem in Ingres 10

Thu May 17 13:43:49 UTC 2018

On Thu, 17 May 2018 13:24:56 +0000, Martin Bowes
<martin.bowes at ndph.ox.ac.uk> wrote:

>Hi Mark,
>
>That trace shows three successive update attempts each with a different message_id. The first one updates no rows the others update a single row.

Yes, but ... they all should update exactly one row.

>So can you do a:
>select count(*) from db_msg where message_id = ' 100055700000XDBW' and queue <> ' log_20150325' /* rowcount = 0 */

0 [This was 1 when the update first failed.  It was subsequently
updated succesfully].

>select count(*) from db_msg where message_id = ' 400055700000XDBW' and queue <> ' log_20150325' /* rowcount = 1 */

0

>select count(*) from db_msg where message_id = ' 500055700000XDBW' and queue <> ' log_20150325' /* rowcount = 1 */

0

>Marty
>
>-----Original Message-----
>From: Mark [mailto:i at dontgetlotsofspamanymore.net] 
>Sent: 17 May 2018 14:17
>To: info-ingres at lists.planetingres.org
>Subject: Re: [Info-ingres] Weird problem in Ingres 10
>
>On Thu, 17 May 2018 13:03:16 +0000, Martin Bowes
><martin.bowes at ndph.ox.ac.uk> wrote:
>
>>Sorry, my bad that should have been a line starting: SESSION BEGINS
>>
>>Can you send the update queries and parameters (if any) from the good and bad cases. Those won't show any private data, so it should be cool.
>
>Cheers.  I have emailed you the logs.
>
>>Marty
>>
>>-----Original Message-----
>>From: Mark [mailto:i at dontgetlotsofspamanymore.net] 
>>Sent: 17 May 2018 13:51
>>To: info-ingres at lists.planetingres.org
>>Subject: Re: [Info-ingres] Weird problem in Ingres 10
>>
>>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
>>>>>>> 
>>>>>>> -- 
>>>>>>> <insert witty sig here>
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