statistics: add GC for mysql.column_stats_usage (#29183)

pingcap · Oct 29, 2021 · c0024d7 · c0024d7
1 parent 6a62f9d
commit c0024d7
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Showing 2 changed files with 29 additions and 0 deletions.
diff --git a/statistics/handle/gc.go b/statistics/handle/gc.go
@@ -176,6 +176,12 @@ func (h *Handle) deleteHistStatsFromKV(physicalID int64, histID int64, isIndex i
 	if _, err := exec.ExecuteInternal(ctx, "delete from mysql.stats_fm_sketch where table_id = %? and hist_id = %? and is_index = %?", physicalID, histID, isIndex); err != nil {
 		return err
 	}
+	if isIndex == 0 {
+		// delete the record in mysql.column_stats_usage
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.column_stats_usage where table_id = %? and column_id = %?", physicalID, histID); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
@@ -221,6 +227,9 @@ func (h *Handle) DeleteTableStatsFromKV(statsIDs []int64) (err error) {
 		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_fm_sketch where table_id = %?", statsID); err != nil {
 			return err
 		}
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.column_stats_usage where table_id = %?", statsID); err != nil {
+			return err
+		}
 	}
 	return nil
 }

diff --git a/statistics/handle/gc_test.go b/statistics/handle/gc_test.go
@@ -134,3 +134,23 @@ func (s *testStatsSuite) TestGCExtendedStats(c *C) {
 	c.Assert(h.GCStats(s.do.InfoSchema(), ddlLease), IsNil)
 	testKit.MustQuery("select name, type, column_ids, stats, status from mysql.stats_extended").Sort().Check(testkit.Rows())
 }
+
+func (s *testStatsSuite) TestGCColumnStatsUsage(c *C) {
+	defer cleanEnv(c, s.store, s.do)
+	testKit := testkit.NewTestKit(c, s.store)
+	testKit.MustExec("use test")
+	testKit.MustExec("create table t(a int, b int, c int)")
+	testKit.MustExec("insert into t values (1,1,1),(2,2,2),(3,3,3)")
+	testKit.MustExec("analyze table t")
+	testKit.MustQuery("select count(*) from mysql.column_stats_usage").Check(testkit.Rows("3"))
+	testKit.MustExec("alter table t drop column a")
+	testKit.MustQuery("select count(*) from mysql.column_stats_usage").Check(testkit.Rows("3"))
+	h := s.do.StatsHandle()
+	ddlLease := time.Duration(0)
+	c.Assert(h.GCStats(s.do.InfoSchema(), ddlLease), IsNil)
+	testKit.MustQuery("select count(*) from mysql.column_stats_usage").Check(testkit.Rows("2"))
+	testKit.MustExec("drop table t")
+	testKit.MustQuery("select count(*) from mysql.column_stats_usage").Check(testkit.Rows("2"))
+	c.Assert(h.GCStats(s.do.InfoSchema(), ddlLease), IsNil)
+	testKit.MustQuery("select count(*) from mysql.column_stats_usage").Check(testkit.Rows("0"))
+}