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ORACLE9.2里面创建全文索引--(3)

原创 Linux操作系统 作者:bpmfhu 时间:2019-06-20 15:00:07 0 删除 编辑
全文索引的维护

全文索引的维护主要有2个部分的工作:

1.同步:

BEGIN
ctx_ddl.sync_index('CNDYBK.CIDX_IMAGE_TITLE' , '50M');
END;
/

2.优化:

BEGIN
ctx_ddl.optimize_index('CNDYBK.CIDX_STORY_TITLE', 'FULL');
END;
/

注意的是,itpub的网友并不建议对全文索引的表,进行analyze.

我查了一下otn的文档,里面有这么一段话:

  There is no benefit to having cost-based-optimization of those queries because the  rule-based query plan is ALWAYS optimal.  The Cost Based Optimizer  can only slow them down.    As for the Text (Domain) index, in our example the BOOKS_INDEX index.  A context index that has been ANALYZED will participate in cost-based optimization.  A context index that has not been ANALYZED cannot provide selectivity and cost estimates, so it will do rule-based optimization.  Thus, ANALYZING the domain index can change the behavior and performance of the context index.  Whether or not it is "required" is up to your application. 

  So:  ANALYZE the domain index if you want to.  Do NOT ANALYZE the underlying DR$ tables respective DR# tables.

来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/4096/viewspace-52482/,如需转载,请注明出处,否则将追究法律责任。

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