Re: tune between query/join
- From: David Fitzjarrell <oratune@xxxxxxxxx>
- To: "ax.mount@xxxxxxxxx" <ax.mount@xxxxxxxxx>
- Date: Fri, 21 Oct 2011 08:41:03 -0700 (PDT)
How can you even hope to relate what's in tmp_account with the data in account
and make any sense of it? I hate to say this but if this is how he models
processes you are much better off with him gone. It appears you need someone
who can actually create a usable process model and schema and start this
process over. We are in the midst of a major data migration where I am
employed but our process model makes sense and correctly maps data from one
system to another
because the proper relationships exist.
I can't see how you can undertake this migration when the schema is absent the
necessary relations.
David Fitzjarrell
From: amonte <ax.mount@xxxxxxxxx>
To: David Fitzjarrell <oratune@xxxxxxxxx>
Cc: Oracle-L Group <oracle-l@xxxxxxxxxxxxx>
Sent: Friday, October 21, 2011 7:09 AM
Subject: Re: tune between query/join
unfortunatey there arent any common columns, this is a pity really
this is a data migration process and the guy who modelled this left the
company :-(
and yes, it reads million of rows even the entire tables are cached, I dont
think this would work even with exadata
let me get some test data...
2011/10/21 David Fitzjarrell <oratune@xxxxxxxxx>
> That would be a merge join cartesian, not what you want, really as it
> returs 1,200,000,000,000 rows with at most 8,000,000 rows of actually
> useful results (the result set should be somewhere between 1 and 8,000,000
> depending upon how many rows in account match rows in tmp_account). There
> must be some common column between the two tables to effect a proper join.
> If not then this query is useless and is simply consuming resources better
> used for more productive queries.
>
> Please provide create table statements for both tables and some sample
> data.
>
> David Fitzjarrell
>
>
> *From:* amonte <ax.mount@xxxxxxxxx>
> *To:* Oracle-L Group <oracle-l@xxxxxxxxxxxxx>
> *Sent:* Thursday, October 20, 2011 10:41 PM
> *Subject:* tune between query/join
>
> Hello everyone
> I am running a query which looks like following (running in 10.2.0.4):
>
> select a.account_number, a.id, b.*
> from account a, tmp_account b
> where b.amount between a.lowest_amount and a.highest_amount
>
> account has 8000000 rows and tmp_account 150000, the execution plan shows
> merge sort join as expected, this query takes around 5 hours to run, is
> there anyway to improve this?
>
>
> Alex
>
>
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
>
>
--
//www.freelists.org/webpage/oracle-l
--
//www.freelists.org/webpage/oracle-l
Other related posts:
