Re: IOT secondary index creation can't use parallel (30hours)
- From: Eagle Fan <eagle.f@xxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Wed, 18 Jan 2012 21:27:49 +0800
At first, I suspect it's related to overflow segment, but seems it's not.
I created same small IOT tables on both databases and run the secondary
index creation sql again.
On 10203 database, it used parallel index fast scan read but on 11202
database, it still used single thread db file sequential read.
Thanks.
On Wed, Jan 18, 2012 at 9:22 PM, Eagle Fan <eagle.f@xxxxxxxxx> wrote:
> Hi:
>
> I created IOT secondary index using parallel 4 online option on two
> databases. One database is 10203 version and another one is 11202 version.
>
> On 10203 version, the SQL finished in 20 minutes, but on 11202 version, it
> used 30 hours. The two databases have same table/index structure and both
> of them are about 100GB.
>
> On 10203 database, it used PK index fast full scan with parallel 4 as
> expected. But on 11202 database, it didn't use parallel index fast full
> scan, it used single thread db file sequential read on PK index. That's why
> it took 30 hours.
>
> I don't know why on 11202 version, the secondary IOT index creation used
> less effecient db file sequential read instead of index fast full scan.
>
> Is there any way to make it faster?
>
> The SQL is like this:
>
> CREATE INDEX T_IDX2 ON T (
> a,b,c)tablespace index01 parallel 4 ONLINE;
>
> Thanks in advance.
>
> --
> Eagle Fan
>
--
Eagle Fan (www.dbafan.com)
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