关于统计中表字段索引所搜集的相关信息有那些....[@more@]
Statistics generated include the following:
n
Table statistics
– Number of
rows
– Number of
blocks
– Average row length
n
Column statistics
– Number of
distinct values (NDV) in column
– Number of
nulls in column
– Data distribution (histogram)
n
Index statistics
– Number of
leaf blocks
– Levels
– Clustering factor
n
System statistics
– I/O
performance and utilization
– CPU
performance and utilization
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/8128313/viewspace-911827/ ，如需转载，请注明出处，否则将追究法律责任。
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