Re: Correlated update

From: Gerard H. Pille <ghp_at_skynet.be>
Date: Sun, 05 Dec 2010 12:50:53 +0100
Message-ID: <4cfb7c2f$0$14263$ba620e4c_at_news.skynet.be>

bob123 schreef:
>>> Try posting the plan. The distinct perhaps means a full table scan
>>> of ...icld for each row of ...formitems. Would you happen to have any
>>> indices? Does your cpu go nuts? Does statspack have something to say
>>> about what is going on in that time period?
>>>
>>
> I update all the table T_SUBJECTVISITFORMITEMS
> maybe I can avoid this with a CTAS ?
>
> below the plan:
> Plan
> UPDATE STATEMENT ALL_ROWS Cost: 39,539 Bytes: 68,254,407 Cardinality:
> 2,527,941
> 5 UPDATE SYSTEM.T_SUBJECTVISITFORMITEMS
> 1 TABLE ACCESS FULL TABLE SYSTEM.T_SUBJECTVISITFORMITEMS Cost: 39,539
> Bytes: 68,254,407 Cardinality: 2,527,941
> 4 HASH UNIQUE Cost: 3 Bytes: 27 Cardinality: 1
> 3 TABLE ACCESS BY INDEX ROWID TABLE SYSTEM.T_ITEMFIRSTDATA_STATUS_ICLD
> Cost: 2 Bytes: 27 Cardinality: 1
> 2 INDEX RANGE SCAN INDEX SYSTEM.T_ITEMFIRSTDATA_STATUS Cost: 1
> Cardinality: 1
>
>

Wow, my mistake, Oracle does create indexes on its own. Received on Sun Dec 05 2010 - 05:50:53 CST