executor: fix select wrong partition for hash partition table (#50430)

close #50427

pkg/planner/core/rule_partition_processor.go

@@ -181,30 +181,27 @@ func (s *partitionProcessor) getUsedHashPartitions(ctx sessionctx.Context,
 				}
 
 				var rangeScalar uint64
-				var offset int64
 				if mysql.HasUnsignedFlag(col.RetType.GetFlag()) {
 					// Avoid integer overflow
 					if uint64(posHigh) < uint64(posLow) {
 						rangeScalar = 0
 					} else {
 						rangeScalar = uint64(posHigh) - uint64(posLow)
-						offset = int64(uint64(posLow) % uint64(numPartitions))
 					}
 				} else {
 					// Avoid integer overflow
 					if posHigh < posLow {
 						rangeScalar = 0
 					} else {
 						rangeScalar = uint64(posHigh - posLow)
-						offset = posLow % int64(numPartitions)
 					}
 				}
 
 				// if range is less than the number of partitions, there will be unused partitions we can prune out.
 				if rangeScalar < uint64(numPartitions) && !highIsNull && !lowIsNull {
 					var i int64
 					for i = 0; i <= int64(rangeScalar); i++ {
-						idx := mathutil.Abs(offset+i) % int64(numPartitions)
+						idx := mathutil.Abs((posLow + i) % int64(numPartitions))
 						if len(partitionNames) > 0 && !s.findByName(partitionNames, pi.Definitions[idx].Name.L) {
 							continue
 						}

tests/integrationtest/r/executor/partition/issues.result

@@ -465,7 +465,7 @@ CREATE TABLE `t` (
 PRIMARY KEY (`col_51`) /*T![clustered_index] CLUSTERED */
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
 PARTITION BY HASH (`col_51`) PARTITIONS 5;
-insert into t values (9223372036854775807), (9223372036854775808), (9223372036854775809);
+insert into t values (9223372036854775807), (9223372036854775808), (9223372036854775809), (9223372036854775812), (9223372036854775813);
 analyze table t;
 desc SELECT * FROM `t` WHERE `t`.`col_51` BETWEEN 9223372036854775807 AND 9223372036854775808;
 id	estRows	task	access object	operator info
@@ -475,6 +475,14 @@ SELECT * FROM `t` WHERE `t`.`col_51` BETWEEN 9223372036854775807 AND 92233720368
 col_51
 9223372036854775807
 9223372036854775808
+explain select * from t where col_51 between 9223372036854775812 and 9223372036854775813;
+id	estRows	task	access object	operator info
+TableReader_6	2.00	root	partition:p3,p4	data:TableRangeScan_5
+└─TableRangeScan_5	2.00	cop[tikv]	table:t	range:[9223372036854775812,9223372036854775813], keep order:false
+select * from t where col_51 between 9223372036854775812 and 9223372036854775813;
+col_51
+9223372036854775812
+9223372036854775813
 drop table if exists t;
 CREATE TABLE `t` (
 `col_51` bigint(20) NOT NULL,
@@ -557,3 +565,11 @@ col_29
 -1
 0
 1
+explain select * from t where col_29 between -7 and -6;
+id	estRows	task	access object	operator info
+TableReader_7	1.00	root	partition:p0,p6	data:Selection_6
+└─Selection_6	1.00	cop[tikv]		ge(executor__partition__issues.t.col_29, -7), le(executor__partition__issues.t.col_29, -6)
+  └─TableFullScan_5	48.00	cop[tikv]	table:t	keep order:false
+select * from t where col_29 between -7 and -6;
+col_29
+-6

tests/integrationtest/t/executor/partition/issues.test

@@ -263,12 +263,16 @@ CREATE TABLE `t` (
   PRIMARY KEY (`col_51`) /*T![clustered_index] CLUSTERED */
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
 PARTITION BY HASH (`col_51`) PARTITIONS 5;
-insert into t values (9223372036854775807), (9223372036854775808), (9223372036854775809);
+insert into t values (9223372036854775807), (9223372036854775808), (9223372036854775809), (9223372036854775812), (9223372036854775813);
 analyze table t;
 desc SELECT * FROM `t` WHERE `t`.`col_51` BETWEEN 9223372036854775807 AND 9223372036854775808;
 --sorted_result
 SELECT * FROM `t` WHERE `t`.`col_51` BETWEEN 9223372036854775807 AND 9223372036854775808;
 
+explain select * from t where col_51 between 9223372036854775812 and 9223372036854775813;
+--sorted_result
+select * from t where col_51 between 9223372036854775812 and 9223372036854775813;
+
 drop table if exists t;
 CREATE TABLE `t` (
   `col_51` bigint(20) NOT NULL,
@@ -328,3 +332,8 @@ explain select * from t where col_29 between -2 and 1;
 --sorted_result
 select * from t where col_29 between -2 and 1;
 
+# TestIssue50427
+explain select * from t where col_29 between -7 and -6;
+--sorted_result
+select * from t where col_29 between -7 and -6;
+