【TUNE_ORACLE】查看每个列的选择性和基数SQL参考

实验环境

搭建平台：VMware Workstation

OS：RHEL 6.10

Grid&DB：Oracle 11.2.0.4 SQL参考select a.column_name,       b.num_rows,       a.num_distinct cardinality,       round(a.num_distinct / b.num_rows * 100, 2) selectivity,       a.histogram,       a.num_buckets  from dba_tab_col_statistics a, dba_tables b where a.owner = b.owner   and a.table_name = b.table_name   and a.owner = 'xxx'  --用户名   and a.table_name = 'xxx';  --表名