tcl-tdbc

[Tcl-tdbc] $resultset close

[Patrick D. <pat...@ac...>]

In the documentation we have the following:

 

$resultset close

The close object command deletes the result set and frees any associated
system resources.

 

If you do not close the result set each time, does tdbc automatically clean
up the system resources on the subsequent prepare / execute? In other words,
besides being good practice is it required?

 

Thanks

 

Patrick Dunnigan

Email: pat...@ac...

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<file:///C:\Documents%20and%20Settings\pdunnigan\Application%20Data\Microsof
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Re: [Tcl-tdbc] $resultset close

[Kevin K. <kk...@ny...>]

Patrick Dunnigan wrote:
> In the documentation we have the following:
> 
>  
> 
> /$resultset/ *close*
> 
> The *close* object command deletes the result set and frees any 
> associated system resources.
> 
>  
> 
> If you do not close the result set each time, does tdbc automatically 
> clean up the system resources on the subsequent prepare / execute? In 
> other words, besides being good practice is it required?

Yes, it's required.  You can have as many prepared statements per
connection as you please, and as many result sets per statement as
you please.  Close them when you're done with them.

-- 
73 de ke9tv/2, Kevin

Re: [Tcl-tdbc] $resultset close

[Patrick D. <pat...@ac...>]

Are there any resources wasted if I do the following:

set sql "update mytable set column1 = 'ABC123'"
set result [[$conn prepare $sql] execute]


and don't call $result close?

In other words, for update / insert / etc. statements do we have to call
$results close. 

Presently I am only calling $results close on select statements. However
some of these processes run for days, even weeks or months on end so I don't
want to cause a memory leak or whatever. 

Thanks,


Patrick Dunnigan

Email: pat...@ac...

Visit us at www.activecompliance.com

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to which it is addressed, and may contain information that is confidential.
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-----Original Message-----
From: Kevin Kenny [mailto:kk...@ny...] 
Sent: Wednesday, February 18, 2009 12:39 AM
To: pat...@ac...
Cc: tcl...@li...
Subject: Re: [Tcl-tdbc] $resultset close

Yes, it's required.  You can have as many prepared statements per
connection as you please, and as many result sets per statement as
you please.  Close them when you're done with them.

-- 
73 de ke9tv/2, Kevin

Re: [Tcl-tdbc] $resultset close

[Kevin K. <kk...@ny...>]

Patrick Dunnigan wrote:
> Are there any resources wasted if I do the following:
> 
> set sql "update mytable set column1 = 'ABC123'"
> set result [[$conn prepare $sql] execute]
> 
> 
> and don't call $result close?
> 
> In other words, for update / insert / etc. statements do we have to call
> $results close. 
> 
> Presently I am only calling $results close on select statements. However
> some of these processes run for days, even weeks or months on end so I don't
> want to cause a memory leak or whatever. 

Yes, all result sets, even ones of zero rows, must be closed.
For INSERT, UPDATE and DELETE statements, I've taken to writing:

     $conn allrows {UPDATE mytable SET column1 = :input}

because that makes a list of the zero rows of the result set and
returns that empty list, cleaning up the prepared statement and
the result set.

I also tend to prepare my statements once in program initialization
(or on demand) and keep them around. At least if there's a likelihood
that I'll be using them more than once.

-- 
73 de ke9tv/2, Kevin