Index Condition Pushdown 将Index Filter 从 Server 层 Push Down 到了引擎层,减少了因回表产生的磁盘 I/O,提高了 SQL 执行效率 参考 Index Condition Pushdown Optimization[2]Index Condition Pushdown[3] 原文:juejin.cn/post/74128619 作者:青石路 [1] juejin.cn/post/74117457 juejin.cn/post/74117457 [2]...
[2]https://dev.mysql.com/doc/refman/5.7/en/index-condition-pushdown-optimization.html: https://dev.mysql.com/doc/refman/5.7/en/index-condition-pushdown-optimization.html [3]https://mariadb.com/kb/en/index-condition-pushdown/: https://mariadb.com/kb/en/index-condition-pushdown/ ...
Index Condition Pushdown optimization is used for therange,ref,eq_ref, andref_or_nullaccess methods when there is a need to access full table rows(ICP是为需要使用range,ref,eq_ref和ref_or_null方法访问全表数据优化的).另外MariaDB也针对索引下推做了一个优化,Batched Key Access. This strategy c...
(出自 https://dev.mysql.com/doc/refman/8.0/en/index-condition-pushdown-optimization.html) 先说“下推”这个概念,是相对Server层和引擎层(也就是Innodb引擎)而言的,“索引下推”指的是Server层把where条件下推到innodb去执行。 这里还有一个背景知识,对于where条件会分为两类:通常用到聚簇索引或者二级索引的...
To understand how this optimization works, first consider how an index scan proceeds when Index Condition Pushdown is not used: Get the next row, first by reading the index tuple, and then by using the index tuple to locate and read the full table row. ...
Index Condition Pushdown optimization isused for therange,ref,eq_ref, andref_or_nullaccess methodswhen there is a need to access full table rows. This strategy can be used forInnoDBandMyISAMtables. (Note that index condition pushdown isnot supported with partitioned tables in MySQL 5.6; this...
Index Condition Pushdown is an optimization that is applied for access methods that access table data through indexes: range, ref, eq_ref, ref_or_null, and Batched Key Access. The idea is to check part of the WHERE condition that refers to index fields (we call it Pushed Index Condition...
8.2.1.5 Index Condition Pushdown Optimization Index Condition Pushdown (ICP) is an optimization for the case where MySQL retrieves rows from a table using an index. Without ICP, the storage engine traverses the index to locate rows in the base table and returns them to the MySQL server which...
有点小激动-Index Condition Pushdown Optimization 今天有点激动,因为在5.6的官方文档中看到Index Condition Pushdown Optimization,简称ICP,这意味着什么,意味着mysql的优化器能够像oracle的优化器那样对索引列进行过滤,而不是像以前版本中只能使用前缀索引来过滤满足查询条件的行;...
To understand how this optimization works, first consider how an index scan proceeds when Index Condition Pushdown is not used: Get the next row, first by reading the index tuple, and then by using the index tuple to locate and read the full table row. Test the part of the WHERE con...