# 查看查询执行计划 OceanBase 的 SQL 引擎支持执行计划解析和缓存技术，可以通过分析查询语句的执行计划来分析查询性能。执行计划查看的语法格式如下： ~~~ explain [extended] query_statment ; ~~~ **示例：查看查询执行计划** ~~~ obclient> EXPLAIN select count(*) from stok \G *************************** 1. row *************************** Query Plan: ======================================================== |ID|OPERATOR |NAME |EST. ROWS|COST | -------------------------------------------------------- |0 |SCALAR GROUP BY | |1 |600337| |1 | PX COORDINATOR | |1 |485729| |2 | EXCHANGE OUT DISTR |:EX10000|1 |485729| |3 | MERGE GROUP BY | |1 |485729| |4 | PX PARTITION ITERATOR| |600000 |371122| |5 | TABLE SCAN |stok |600000 |371122| ======================================================== Outputs & filters: ------------------------------------- 0 - output([T_FUN_COUNT_SUM(T_FUN_COUNT(*))]), filter(nil), group(nil), agg_func([T_FUN_COUNT_SUM(T_FUN_COUNT(*))]) 1 - output([T_FUN_COUNT(*)]), filter(nil) 2 - output([T_FUN_COUNT(*)]), filter(nil), dop=1 3 - output([T_FUN_COUNT(*)]), filter(nil), group(nil), agg_func([T_FUN_COUNT(*)]) 4 - output([stok.s_i_id]), filter(nil) 5 - output([stok.s_i_id]), filter(nil), access([stok.s_i_id]), partitions(p[0-5]) ~~~