[teiid-users] [teiid-dev] query plan changes

[Ken Johnson]

Steven Hawkins wrote:
> Yes the defaults are both off.  The SET command is scoped to the session and currently has the same affect as changing the connection or datasource properties.  Using NOEXEC is the same as Sybase and SQLServer, which also use the EXEC syntax for calling procedures.  We can of course make it whatever we want.
>   
I'm fine with NOEXEC particularly given the precedent.
> ----- Original Message -----
> From: "Ken Johnson" <kejohnso at redhat.com>
> To: "Steven Hawkins" <shawkins at redhat.com>
> Cc: "teiid-users" <teiid-users at lists.jboss.org>, "teiid-dev" <teiid-dev at lists.jboss.org>, "teiid-designer-dev" <teiid-designer-dev at lists.jboss.org>
> Sent: Tuesday, April 6, 2010 2:10:59 PM GMT -06:00 US/Canada Central
> Subject: Re: [teiid-dev] query plan changes
>
> Steven Hawkins wrote:
>   
>> Hello all,
>>
>> Currently we have OPTION SHOWPLAN PLANONLY DEBUG to control planning and execution.  The drawbacks are that this introduces three reserved words (SHOWPLAN, PLANONLY, DEBUG) and it's only applicable to the top level user query.
>>
>> The proposed replacement makes use of https://jira.jboss.org/jira/browse/TEIID-906, which added basic support for a set statement:
>>
>> SET SHOWPLAN [ON|DEBUG|OFF]
>> SET NOEXEC [ON|OFF] - general replacement for PLANONLY, will not execute the command if ON
>>   
>>     
> This seems a reasonable way to reduce the keywords and allow repetitive 
> executions without having to modify the query syntax each time.  How are 
> these commands scoped, per session?  It would be cool if these could be 
> used to enable plan output for a query coming from an application where 
> the user cannot easily change the query itself.  Presumably defaults 
> would be SHOWPLAN=OFF and NOEXEC=OFF.
>
> Given that EXEC is a reserved word for executing a procedure, do you 
> think NOEXEC might cause confusion (users thinking it's the negative 
> form of EXEC)?
>
>   
>> I would also like to remove most of the logic surrounding the org.teiid.client.plan.PlanNode class.  The visitors, display helpers, etc.  Since we don't publish a meaningful schema for the xml form(s) or document the property keys we might as well assume that we're the primary consumers and forgo the flexibility.  
>>   
>>     
> Don't know about this one.  Hard to foresee how users might consume the 
> query plan XML in the future. 
>
>   
>> Any thoughts?  
>>
>> Steve
>>
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>>   
>>     
>
>
>   


-- 
Ken Johnson
Sr. Product Manager
JBoss Middleware Business Unit
Red Hat, Inc
978.392.3917
ken.johnson at redhat.com