Den 2013-09-19 19:07 skrev Leyne, Sean såhär:
>
> > >I do expect more than on PLAN dues to the derived table and the union,
> > >but there seems to be a comma missing before the PLAN on line 05 at 
> least.
> > >
> > >I don't really need to understand the plan, but I wanted to bring it up
> > >in case there's a bug that needs to be fixed...
> >
> > Hi Kjell, I doubt this is an error. The place you think a comma is 
> missing, is
> > where your UNION is. I must admit that I've never before really noticed
> > whether or not there is a comma in the plan with union, but when I try
>
> Adding to Set's typically excellent comments, I would suggest that you 
> look at using Common Table Expression (CTE) for your FE Företag inner 
> join.
>
> The reason that the PLAN is showing a NATURAL access for FE Företag is 
> because the SELECT from Företag is not getting the JOIN criteria, 
> using a CTE would change that.
>

Strangely enough I SET's reply hasen't shown up in my inbox, and yes I 
did check the spam/garbage folder. Anyway, I know separate subplans are 
enumerated without comma, but it seems odd, then, that it doesn't prefix 
*all* subplans with "PLAN". Shouldn't it appear like this?

01_PLAN SORT (
02___JOIN (
03_____JOIN (
04_______(
05_________PLAN FE Företag NATURAL
06_________PLAN JOIN (
07___________FE BIADR NATURAL,
08___________FE BI INDEX (IX_PK_Befattningsinnehav),
09___________FE BEF INDEX (IX_PK_Befattning)
10_________)
11_______),
12_______F INDEX (IX_PK_Företag),
13_______E INDEX (IX_PK_Epostadress),
14_______STATUS INDEX (IX_PK_Företagsstatus)
15_____),
16_____JURFORM INDEX (IX_PK_JuridiskForm),
17_____BVSTATUS INDEX (IX_PK_BVstatus)
18___)
19_)

The lines 05-10 is the plan returned if only the derived table part is 
executed alone (minus the FE prefixes for the table aliases of course). 
Putting a paranthesis around that subplan makes sense, and makes the 
wrapping join contain a correctly comma separated list of "items". 
Without the paranthesis it's not clear that line 05 and lines 06-10 are 
subplans that are unioned, and then joined.

At the least, it seems incorrect that line 05 is missing the "PLAN" prefix.

Regards,
Kjell

-- 
--------------------------------------
Kjell Rilbe
DataDIA AB
E-post: [email protected]
Telefon: 08-761 06 55
Mobil: 0733-44 24 64




------------------------------------

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Visit http://www.firebirdsql.org and click the Resources item
on the main (top) menu.  Try Knowledgebase and FAQ links !

Also search the knowledgebases at http://www.ibphoenix.com 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/firebird-support/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/firebird-support/join
    (Yahoo! ID required)

<*> To change settings via email:
    [email protected] 
    [email protected]

<*> To unsubscribe from this group, send an email to:
    [email protected]

<*> Your use of Yahoo! Groups is subject to:
    http://info.yahoo.com/legal/us/yahoo/utos/terms/

Reply via email to