Comments on: SQL command Leaving File open

By: tomliotta

tomliotta — Sun, 22 Jan 2012 06:35:31 +0000

Needed to add CONFLICT(*RQSRLS) to the ALCOBJ command of those files so that it would “hard close” those files. Then our CL could…

This is a very valuable item to post back here. It will be potentially useful to many others.

Thanks for remembering to come back and adding the update.

Tom

By: beanbaggs

beanbaggs — Fri, 20 Jan 2012 14:02:55 +0000

It ended up being “pseudo-closes” that IBM puts on files when using SQL to help with speed. Needed to add CONFLICT(*RQSRLS) to the ALCOBJ command of those files so that it would “hard close” those files. Then our CL could ALCOBJ the files. Looks like most commands will “hard close” pseudo-closes”, but ALCOBJ does not, and that is why the CONFLICT(*RQSRLS) was added to ALCOBJ.

By: The Most-Watched IT Questions: November 15, 2011 - ITKE Community Blog

The Most-Watched IT Questions: November 15, 2011 - ITKE Community Blog — Tue, 15 Nov 2011 13:25:00 +0000

[...] BeanBaggs is running into some file closing operations on AS/400, but members help him figure out what’s going [...]

By: beanbaggs

beanbaggs — Tue, 08 Nov 2011 19:10:38 +0000

We are not manually opening the Table adapter, so he figured the garbage clean up should take care of the close, but apparently not. Tried to use the .Dispose and that didn’t work either, so the VB person is going to try to close the Table Adapter connection manually and see what that does.

By: tomliotta

tomliotta — Fri, 04 Nov 2011 21:59:30 +0000

Sorry if this answer is too simplistic…

Not simplistic at all. The obvious answer is often the best one. It’s easy to forget to ask “Was the connection actually closed?”

Tom

By: tomliotta

tomliotta — Fri, 04 Nov 2011 21:56:30 +0000

I only see the LazyClose associated with the ODBC connection not an OLE DB one.

I also don’t see one anywhere, which makes me wonder how/if an OLE DB client can have any control.

But the default for ODBC should be ‘Off’ anyway in current releases.

Do you know if you have a QAQQINI file that controls options? The OPEN_CURSOR_CLOSE_COUNT and OPEN_CURSOR_THRESHOLD options can control pseudo-opens/closes.

Tom

By: beanbaggs

beanbaggs — Fri, 04 Nov 2011 19:23:29 +0000

Searching online I only see the LazyClose associated with the ODBC connection not an OLE DB one. I will ask him when he gets back to look for that and what DoneThat posted. Will post results.

By: tomliotta

tomliotta — Fri, 04 Nov 2011 19:22:25 +0000

Note that the database servers may choose not to close open files in order to avoid having to do full opens and full closes for every connection. The “lazy close” attribute of a connection is one way of giving permission to only do what’s called “pseudo-opens” and “pseudo-closes”.

Holding files open for later transactions can make significant improvement in performance. (Also note that this is perhaps more important for sites that may have hundreds or thousands of QZDASOINIT jobs with active connections at once, handling a thousand transactions or more per second.)

Tom

By: donethat

donethat — Fri, 04 Nov 2011 16:35:42 +0000

Sorry if this answer is too simplistic but I close everything after each task (VBA)…

‘ Close the AS400 connection and clean up.

Set cmdAS400Command = Nothing
Set conAS400System = Nothing

If I had to open another workbook then…

‘ Close the Excel connection and clean up.

Set cmExcelCommand = Nothing
Set cnExcelWorkbook = Nothing

With 10 – 20 regular users, AS400 does not have any files left open. Also, no noticeable delay upon reopening to do the next task.

Gary

By: tomliotta

tomliotta — Thu, 03 Nov 2011 22:28:22 +0000

I don’t have an environment at the moment to look at the settings specific for IBMDA400, but have your developer look for a LazyClose option. Whichever way it is set — Yes/No or On/Off or checked/unchecked — try setting it the opposite way.

Post back with results.

Tom