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关于Oracle 11g 统计信息的收集

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关于Oracle 11g 统计信息的收集 1.对于 ANALYZE 请不要再使用compute 、estimate 选项,他们已经被废弃了。 此外analyze 搜集的统

关于Oracle 11g 统计信息的收集

1.对于 ANALYZE 请不要再使用compute 、estimate 选项,他们已经被废弃了。

此外analyze 搜集的统计信息不能被cost-based optimizer优化器所使用,只能在以下情形使用:

for statistics collection not related to the cost-based optimizer, such

as:

■ To use the  VALIDATE  or  LIST  CHAINED  ROWS clauses

■ To collect information on freelist blocks

must use the ANALYZE statement to collect statistics

unrelated to the optimizer, such as em pty blocks, average space, and so forth.

2.DBMS_STATS

可以并行的搜集统计信息,,为分区对象搜集全局的统计信息。而cbo实际上只使用

dbms_stats搜集的统计信息。

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