create index parted_minmax1i on parted_minmax1 (a, b);
insert into parted_minmax values (1,'12345');
explain (costs off) select min(a), max(a) from parted_minmax where b = '12345';
- QUERY PLAN
--------------------------------------------------------------------------------------------------------
+ QUERY PLAN
+-------------------------------------------------------------------------------------------------------------------
Result
InitPlan 1 (returns $0)
-> Limit
- -> Merge Append
- Sort Key: parted_minmax1.a
- -> Index Only Scan using parted_minmax1i on parted_minmax1
- Index Cond: ((a IS NOT NULL) AND (b = '12345'::text))
+ -> Remote Subquery Scan on all (datanode_1,datanode_2)
+ -> Limit
+ -> Merge Append
+ Sort Key: parted_minmax1.a
+ -> Index Only Scan using parted_minmax1i on parted_minmax1
+ Index Cond: ((a IS NOT NULL) AND (b = '12345'::text))
InitPlan 2 (returns $1)
-> Limit
- -> Merge Append
- Sort Key: parted_minmax1_1.a DESC
- -> Index Only Scan Backward using parted_minmax1i on parted_minmax1 parted_minmax1_1
- Index Cond: ((a IS NOT NULL) AND (b = '12345'::text))
-(13 rows)
+ -> Remote Subquery Scan on all (datanode_1,datanode_2)
+ -> Limit
+ -> Merge Append
+ Sort Key: parted_minmax1_1.a DESC
+ -> Index Only Scan Backward using parted_minmax1i on parted_minmax1 parted_minmax1_1
+ Index Cond: ((a IS NOT NULL) AND (b = '12345'::text))
+(17 rows)
select min(a), max(a) from parted_minmax where b = '12345';
min | max