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最新推荐文章于 2025-07-16 07:00:00 发布

最新推荐文章于 2025-07-16 07:00:00 发布 · 212 阅读

本文通过具体的SQL查询案例，展示了如何分析和优化数据库表't_bme_subscriberrela'的性能。涉及了索引使用情况、表统计信息及空间使用情况等方面的内容。

select index_name,degree,num_rows,distinct_keys from user_indexes where lower(table_name)='t_bme_subscriberrela'

select a.num_rows,a.chain_cnt,a.blocks, round(a.num_rows*a.avg_row_len*1.1/1024/8-a.blocks) sp from user_tables a where lower(table_name)='t_bme_subscriberrela'

SELECT segment_name, bytes / 1024 / 8 jk
FROM user_segments
WHERE lower(segment_name) = 't_bme_subscriberrela'
    OR segment_name IN
       (SELECT index_name
          FROM user_indexes
         WHERE lower(table_name) = 't_bme_subscriberrela')

EXEC dbms_stats.gather_table_stats(ownname       => null,
                                      tabname          => 't_bme_subscriberrela',
                                estimate_percent => dbms_stats.AUTO_SAMPLE_SIZE);