AntDB 数据库分布式功能-FQS增强7

distinctClause 且 distinctClause 里面没有分布列

# 测试用表和数据请参加附录
# 单节点（绑定变量的)：distinctClause且distinctClause里面没有分布列的
antdb=# prepare s_distinct_single(int) as SELECT distinct province FROM fqs_window_test WHERE id = $1;
PREPARE
antdb=# EXPLAIN (verbose) execute s_distinct_single(1);
                                              QUERY PLAN
------------------------------------------------------------------------------------------------------
 Data Node Scan on "__REMOTE_FQS_QUERY__"  (cost=0.00..0.00 rows=0 width=0)
   Output: fqs_window_test.province
   Node expr: $1
   Remote query: SELECT DISTINCT province FROM public.fqs_window_test fqs_window_test WHERE (id = $1)
(4 rows)


# 单节点（静态常量的)：distinctClause且distinctClause里面没有分布列的
antdb=# EXPLAIN (verbose) SELECT distinct province FROM fqs_window_test WHERE id = 1;
                                             QUERY PLAN
-----------------------------------------------------------------------------------------------------
 Data Node Scan on "__REMOTE_FQS_QUERY__"  (cost=0.00..0.00 rows=0 width=0)
   Output: fqs_window_test.province
   Node/s: DN2
   Remote query: SELECT DISTINCT province FROM public.fqs_window_test fqs_window_test WHERE (id = 1)
(4 rows)
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普通子查询

# 测试用表和数据请参加附录
# 带动态参数的普通子查询
antdb=# prepare s_common_subquery(int) as SELECT * FROM (SELECT * FROM fqs_window_test WHERE id = $1) a;
PREPARE
antdb=# EXPLAIN (verbose) execute s_common_subquery(2);
                                                                                                QUERY PLAN

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------
 Data Node Scan on "__REMOTE_FQS_QUERY__"  (cost=0.00..0.00 rows=0 width=0)
   Output: a.id, a.province, a.city
   Node expr: $1
   Remote query: SELECT id, province, city FROM (SELECT fqs_window_test.id, fqs_window_test.province, fqs_window_test.city FROM public.fqs_window_test fqs_window_test WHERE (fqs_window_tes
t.id = $1)) a
(4 rows)


# 带静态常量的普通子查询
antdb=# EXPLAIN (verbose) SELECT * FROM (SELECT * FROM fqs_window_test WHERE id = 2) a;
                                                                                               QUERY PLAN

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------
 Data Node Scan on "__REMOTE_FQS_QUERY__"  (cost=0.00..0.00 rows=0 width=0)
   Output: a.id, a.province, a.city
   Node/s: DN1
   Remote query: SELECT id, province, city FROM (SELECT fqs_window_test.id, fqs_window_test.province, fqs_window_test.city FROM public.fqs_window_test fqs_window_test WHERE (fqs_window_tes
t.id = 2)) a
(4 rows)
复制