Re: parallel execution on partitioned tables (was: Oracle 9.2.0.5 "10046" Tracing ...)

From: Tanel Põder <tanel.poder.003_at_mail.ee>
Date: Tue, 3 Aug 2004 21:20:43 +0300
Message-ID: <035801c47986$96dbeaf0$9c969fd9@porgand>

> I guess it also works that if your index is parallel but the table not
> partitioned then the query will serialize. Though, I have seen parallel
fast
> full index scans on non-partitioned tables. Would this also be because of

Yep, fast full index scans and bitmap fast full index scans can easily be parallelized on non-partitioned indexes (it's not important whether the table itself is partitioned or not, index properties are)

> the indexes created in parallel? Figures with oracle there is always a
> tradeoff. Create indexes in parallel saves a massive amount of time but
then
> you have to alter them noparallel.

You can rebuild your indexes with parallel and alter them back to noparallel afterwards:

SQL> create index i on t(a) parallel;

Index created.

SQL> select degree from user_indexes where index_name = 'I';

DEGREE

DEFAULT 1 row selected.

SQL> alter index i rebuild parallel 2;

Index altered.

SQL> select degree from user_indexes where index_name = 'I';

DEGREE

1 row selected.

SQL> alter index i rebuild noparallel;

Index altered.

SQL> select degree from user_indexes where index_name = 'I';

DEGREE

1 row selected.

Tanel.

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Received on Tue Aug 03 2004 - 13:16:35 CDT