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Re: How to rebuild unusable index in parallel?

From: Jaap W. van Dijk <j.w.vandijk.removethis_at_hetnet.nl>
Date: Fri, 24 Dec 2004 19:36:16 +0100
Message-ID: <baoos09qrno4dhh0kcd4cn61o7j33fd0qe@4ax.com>


On Wed, 22 Dec 2004 23:46:31 +0100, "Access" <idmwarpzone_NOSPAM__at_yahoo.com> wrote:

>
>"Jaap W. van Dijk" <j.w.vandijk.removethis_at_hetnet.nl> wrote in message
>news:8mejs0ta0ca60ohk2lt011r6kmhf9l5pt4_at_4ax.com...
>> On Wed, 22 Dec 2004 16:55:31 +0100, "Access"
>> <idmwarpzone_NOSPAM__at_yahoo.com> wrote:
>>
>> >
>> >"Jaap W. van Dijk" <j.w.vandijk.removethis_at_hetnet.nl> wrote in message
>> >news:8jfis01ctg6jlit3qs69qrsfhv653nr57s_at_4ax.com...
>> >> Hi,
>> >>
>> >> In Oracle 9.2.0.4 on Solaris I have a table with degree DEFAULT and an
>> >> UNUSABLE bitmap index defined on the table, also with degree DEFAULT.
>> >> Parallel ddl has been enabled for the session.
>> >>
>> >> If I do a count on the table which requires a full table scan, the
>> >> table is being read in parallel. If I execute
>> >>
>> >> alter index so_and_so rebuild;
>> >>
>> >> the table is being read noparallel. Why, and how can I force reading
>> >> in parallel?
>> >>
>> >> Jaap.
>> >
>> >Alter index ... rebuild parallel ?
>> >
>> >
>> I don't think this will do the job, because the SQL Reference on the
>> 'ALTER INDEX' statement states:
>>
>> "parallel_clause
>> Use the PARALLEL clause to change the default degree of parallelism
>> for queries and DML on the index."
>>
>> If I am interpreting this correctly this clause changes the
>> degree-property of the index which will change behaviour of
>> *subsequent* DML and queries on the index and not the DDL-statement
>> 'alter index ... rebuild'. But as I mentioned before the index already
>> has degree DEFAULT.
>>
>> But if nobody comes up with another solution I will try this anyway:
>> docs don't always speak the truth.
>>
>> Jaap.
>
>If you do : "alter index ... rebuild parallel", it will rebuild the index in
>parallel + it will change the degree of the index to "parallel". So you
>could do "alter index ... noparallel" after the rebuild to reset the degree
>value.
>
>Matthias
>

Thanks Matthias, I tried it and it worked.

Still agree with myself though that it doesn't work as documented.

Happy Holidays,
Jaap. Received on Fri Dec 24 2004 - 12:36:16 CST

Original text of this message

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