planner: fix wrong result when enabling dynamic mode in partition tab…

…le for tiflash (#37442) (#37454) close #37254
pingcap · Aug 31, 2022 · 473cae5 · 473cae5
1 parent 6c70b69
commit 473cae5
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Showing 2 changed files with 31 additions and 1 deletion.
diff --git a/executor/tiflash_test.go b/executor/tiflash_test.go
@@ -1086,3 +1086,23 @@ func (s *tiflashTestSuite) TestAggPushDownCountStar(c *C) {
 
 	tk.MustQuery("select count(*) from c, o where c.c_id=o.c_id").Check(testkit.Rows("5"))
 }
+
+func (s *tiflashTestSuite) TestTiflashEmptyDynamicPruneResult(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test;")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("CREATE TABLE `IDT_RP24833` (  `COL1` bigint(16) DEFAULT '15' COMMENT 'NUMERIC UNIQUE INDEX',\n  `COL2` varchar(20) DEFAULT NULL,\n  `COL4` datetime DEFAULT NULL,\n  `COL3` bigint(20) DEFAULT NULL,\n  `COL5` float DEFAULT NULL,\n  KEY `UK_COL1` (`COL1`) /*!80000 INVISIBLE */\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin\nPARTITION BY RANGE ((`COL1`-57))\n(PARTITION `P0` VALUES LESS THAN (-3503857335115112215),\n PARTITION `P1` VALUES LESS THAN (-2987877108151063747),\n PARTITION `P2` VALUES LESS THAN (-1981049919102122710),\n PARTITION `P3` VALUES LESS THAN (-1635802972727465681),\n PARTITION `P4` VALUES LESS THAN (1186020639986357714),\n PARTITION `P5` VALUES LESS THAN (1220018677454711359),\n PARTITION `PMX` VALUES LESS THAN (MAXVALUE));")
+	tk.MustExec("alter table IDT_RP24833 set tiflash replica 1")
+	tb := testGetTableByName(c, tk.Se, "test", "IDT_RP24833")
+	err := domain.GetDomain(tk.Se).DDL().UpdateTableReplicaInfo(tk.Se, tb.Meta().ID, true)
+	c.Assert(err, IsNil)
+
+	tk.MustExec("insert into IDT_RP24833 values(-8448770111093677011, \"郇鋺篤堯擈斥鍮啸赠璭饱磟朅闑傒聎疫ᛄ怖霃\", \"8781-05-02 04:23:03\", -27252736532807028, -1.34554e38);")
+	tk.MustExec("set @@tidb_partition_prune_mode = 'dynamic';")
+	tk.MustExec("set @@session.tidb_isolation_read_engines=\"tiflash\";")
+	tk.MustExec("set @@session.tidb_allow_mpp=ON;")
+	tk.MustExec("set @@session.tidb_enforce_mpp = on;")
+	tk.MustQuery("select /*+ read_from_storage(tiflash[t1]) */  * from IDT_RP24833 partition(p3, p4) t1 where t1. col1 between -8448770111093677011 and -8448770111093677011;").Check(testkit.Rows())
+	tk.MustQuery("select /*+ read_from_storage(tiflash[t2]) */  * from IDT_RP24833 partition(p2) t2 where t2. col1 <= -8448770111093677011;").Check(testkit.Rows())
+	tk.MustQuery("select /*+ read_from_storage(tiflash[t1, t2]) */  * from IDT_RP24833 partition(p3, p4) t1 join IDT_RP24833 partition(p2) t2 on t1.col1 = t2.col1 where t1. col1 between -8448770111093677011 and -8448770111093677011 and t2. col1 <= -8448770111093677011;").Check(testkit.Rows())
+}
diff --git a/planner/core/fragment.go b/planner/core/fragment.go
@@ -299,7 +299,17 @@ func partitionPruning(ctx sessionctx.Context, tbl table.PartitionedTable, conds
 		}
 	}
 	if len(ret) == 0 {
-		ret = []table.PhysicalTable{tbl.GetPartition(pi.Definitions[0].ID)}
+		// TiFlash cannot process an empty task correctly, so choose to leave it with some data to read.
+		if len(partitionNames) == 0 {
+			ret = []table.PhysicalTable{tbl.GetPartition(pi.Definitions[0].ID)}
+		} else {
+			for _, def := range pi.Definitions {
+				if def.Name.L == partitionNames[0].L {
+					ret = []table.PhysicalTable{tbl.GetPartition(def.ID)}
+					break
+				}
+			}
+		}
 	}
 	return ret, nil
 }