Re: RAC for DSS queries

In article <adpvvs$1a8hu$1_at_ID-75577.news.dfncis.de>, "Dmitry" says...
>
>Hi,
>
>Can the Oracle Real Application Cluster (RAC) execute ONE large query at ALL
>nodes simultaneously? We are looking for a way to improve our decision
>support system. Currently, our 4 way system is 100% CPU busy when performing
>queries.
>
>
>Best regards, Dmitry
>--
>
>http://www.ispirer.com/products/ - Data migration tool for Oracle, IBM DB2,
>MS SQL Server, Sybase and MySQL.
>
>

Sure, provided the query is executed in parallel across instances. To do this for just this query, you could use a hint like this:

/*+ PARALLEL ( table [{ , integer | , DEFAULT) | , } [ , integer | , DEFAULT ] ] ) */

Direct cut from the doco:

The PARALLEL hint must use the table alias, if an alias is specified in the query. The hint can then take two values, separated by commas after the table name. The first value specifies the degree of parallelism for the given table, and the second value specifies how the table is to be split among the Oracle Real Application Clusters instances. Specifying DEFAULT or no value signifies that the query coordinator should examine the settings of the initialization parameters to determine the default degree of parallelism.

HTH. Additions and corrections welcome.

Pete

SELECT standard_disclaimer, witty_remark FROM company_requirements; Received on Fri Jun 07 2002 - 13:26:55 CDT