Re: Simple performance improvement Re: m:n relations mapping...

[Jakob Braeuchi]

hi andy, oliver,

the patch is checked in.

olli please have a look at the method _storeCollections_ when time 
permits, i think it needs refactoring.

jakob

Andy Malakov wrote:

Thanks. 

In my case eliminating extra SELECT and DELETE for MtoNImplementor (as described below) made batch inserts 5 times faster.

----- Original Message ----- 
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Tuesday, November 04, 2003 5:06 AM
Subject: RE: Simple performance improvement Re: m:n relations mapping...



Hello Andy,

I will have a look at it when I have time.

Please post messages like this to the OJB
users' or developers' list.
Thank you,
Olli
-----Original Message-----
From: Andy Malakov [mailto:[EMAIL PROTECTED]
Sent: Friday, October 31, 2003 9:57 PM
To: [EMAIL PROTECTED]
Subject: Re: Simple performance improvement Re: m:n relations mapping...
Excellent.

Now how about going one step further and eliminating extra SELECT ? :-)))

We do not need to retrieve link table entries in case of new objects.

Class: org.apache.ojb.broker.core.PersistenceBrokerImpl:
Method: storeCollections(Object obj, Vector vecCds, boolean insert)
Line: 789
Now:
...
if (cds.isMtoNRelation())
{
   currentMtoNKeys = getMtoNImplementor(cds, obj);
   // delete unused m:n implementors
   if (!insert)
   {
     deleteMtoNImplementor(cds, obj, (Collection)col, currentMtoNKeys);
   }
}
Better:

...
if (cds.isMtoNRelation())
{
   if (insert) {
        currentMtoNKeys = java.util.Collections.EMPTY_LIST; // assume no
link table entries exist for new objects
   } else {
        currentMtoNKeys = getMtoNImplementor(cds, obj);
        // delete unused m:n implementors
        deleteMtoNImplementor (cds, obj, (Collection) col,
currentMtoNKeys);
   }
}
....
I tested it with P6SPY - the above fix makes extra SELECTs disappear.
This two fixes make batch inserts of complex object work faster :-)
Thanks a lot for you product,
Andy




----- Original Message ----- 
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, October 31, 2003 4:41 AM
Subject: RE: Simple performance improvement Re: m:n relations mapping...



Hello,


-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
I am uncertain whether we should fix it because it does
mean a (very minor) change of behaviour.  I tend to 'yes'.
I have just committed a fix.

Olli

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