SQL> SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); PLAN_TABLE_OUTPUT --- Plan hash value: 1456425992 --- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ---
=# explain select o.o_c_id,i.apd from test_outer o,test_inner i where o.o_id=i.o_id and o.o_w_id=29 and o.o_c_id=1831 and i.o_id<3000;< span=""> QUERY PLAN --- Nested Loop (cost=1000.00..180434.51 rows=2 width=8) Join Filter: (o.o_id = i.o_id) -> Seq ...
Plan的子节点通过Plan的lefttree和righttree指针连接,构成计划树 执行时,Planstate用于记录各节点的执行状态,estate中的es_tupleTable在节点间传递元组。 Excutor输入QueryDesc,包含plannedstmt树形结构;执行前用plannedstmt初始化节点状态树planstate,同时初始化全局状态信息estate。然后执行planstate根节点的函数指针,进入根...
这个参数默认被设置为TEXT。 statement,你想查看其执行计划的任何SELECT、INSERT、UPDATE、DELETE、VALUES、EXECUTE、DECLARE、CREATE TABLE AS或者CREATE MATERIALIZED VIEW AS语句。 常用组合 一般查询 --在不需要真正执行sql时,需把analyze去掉 explain analyze select … ; 查询缓存及详细信息 --在不需要真正执行sql时...
statement,你想查看其执行计划的任何SELECT、INSERT、UPDATE、DELETE、VALUES、EXECUTE、DECLARE、CREATE TABLE AS或者CREATE MATERIALIZED VIEW AS语句。 常用组合 一般查询 代码语言:javascript 代码运行次数:0 运行 AI代码解释 --在不需要真正执行sql时,需把analyze去掉 ...
kms=# show pg_hint_plan.enable_hint_table; pg_hint_plan.enable_hint_table --- off (1 row) kms=# set pg_hint_plan.enable_hint_table=on; SET Time: 0.287 ms kms=# show pg_hint_plan.enable_hint_table; pg_hint_plan.enable_hint_table --- on (1 row) Time: 0.252 ms 设置好了...
postgres=*# explainselectcount(*)frombmscantestwherea>1;QUERY PLAN---Finalize Aggregate(cost=1968.35..1968.36rows=1width=8)->Gather(cost=1568.33..1968.34rows=4width=8)Workers Planned:4->Partial Aggregate(cost=1568.33..1568.34rows=1width=8)->Parallel Seq Scanonbmscantest(cost=0.00..1547.50rows...
set debug_print_plan = off; set debug_pretty_print = on; --例如 explain (analyze,verbose,timing,costs,buffers) select count(*),relkind from pg_class group by relkind order by count(*) desc limit 1; 1. 2. 3. 4. 5. 6.
Plan Width: 1040 1. 2. 3. 4. 5. 6. 7. 8. 9. 输出的执行计划是xml格式 komalog=# explain (format xml) select * from users; <explain xmlns="http://www.postgresql.org/2009/explain">+ <Query> + <Plan> + <Node-Type>Seq Scan</Node-Type> + ...
PREPARE plan_name [ (data_type [, ...] ) ] AS statementREINDEX重建索引。REINDEX { DATABASE | TABLE | INDEX } name [ FORCE ]RELEASE SAVEPOINT删除一个前面定义的保存点。RELEASE [ SAVEPOINT ] savepoint_nameRESET把一个运行时参数值恢复为默认值。