云数据库 GAUSSDB-session级事务下推及相关参数:示例

时间：2024-11-13 14:45:25

云数据库 GAUSSDB

示例

gaussdb=# SET log_min_messages = debug2;
gaussdb=# SET logging_module = 'on(opt_choice)';
gaussdb=# CREATE TABLE t1(a int ,b int);
gaussdb=# PREPARE x(int) AS SELECT * FROM t1;
gaussdb=# EXPLAIN EXECUTE x(10);
NOTICE:  [Choosing C/G/A Plan]: GPlan, reason: Using pbe optimization.
NOTICE:  [Choosing C/G/A Plan]: CPlan, reason: First 5 times using CPlan.
                    QUERY PLAN                    
--------------------------------------------------
 Data Node Scan  (cost=0.00..0.00 rows=0 width=0)
   Node/s: All datanodes
(2 rows)
gaussdb=# DEALLOCATE x;

gaussdb=# PREPARE x(int) AS SELECT * FROM t1;
gaussdb=# SET session_type=single_node;
gaussdb=# SET exec_target_node=datanode1;
gaussdb=# EXPLAIN EXECUTE x(10);
NOTICE:  [Choosing C/G/A Plan]: GPlan, reason: Using pbe optimization.
NOTICE:  [Choosing C/G/A Plan]: GPlan, reason: Using pbe optimization.
                    QUERY PLAN                    
--------------------------------------------------
 Data Node Scan  (cost=0.00..0.00 rows=0 width=0)
   Node/s: datanode1
(2 rows)
gaussdb=# DEALLOCATE x;
gaussdb=# DROP TABLE t1;