As you've seen in the steps above, the optimizer selects the optimal access plan based on available statistics.
您可以从以上步骤看到,这个优化器基于可用的统计信息选择了最优的存取计划。
Accurate index information and statistics are fundamental to cost-based decisions in the query optimizer.
准确的索引信息和统计信息是查询优化器中基于成本的决策的基础。
The optimizer calculates its cardinality estimate — that is, the estimated number of rows returned by the query — based on the statistics available.
优化器根据可用的统计信息计算基数的估计值,即预计查询返回的行数。
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