[DNM]: *: debug flaky import test

pkg/statistics/handle/bootstrap.go

@@ -162,6 +162,9 @@ func (*Handle) initStatsHistograms4ChunkLite(cache statstypes.StatsCache, iter *
 				table.LastAnalyzeVersion = max(table.LastAnalyzeVersion, row.GetUint64(4))
 			}
 		} else {
+			statslogutil.StatsLogger().Info("stat cache map insert col 2",
+				zap.Int64("tableID", table.PhysicalID),
+				zap.Int64("colID", id))
 			table.ColAndIdxExistenceMap.InsertCol(id, statsVer != statistics.Version0 || ndv > 0 || nullCount > 0)
 			if statsVer != statistics.Version0 {
 				// The LastAnalyzeVersion is added by ALTER table so its value might be 0.
@@ -267,6 +270,9 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 				StatsVer:   statsVer,
 			}
 			table.SetCol(hist.ID, col)
+			statslogutil.StatsLogger().Info("stat cache map insert col 3",
+				zap.Int64("tableID", table.PhysicalID),
+				zap.Int64("colID", colInfo.ID))
 			table.ColAndIdxExistenceMap.InsertCol(colInfo.ID, statsVer != statistics.Version0 || ndv > 0 || nullCount > 0)
 			if statsVer != statistics.Version0 {
 				// The LastAnalyzeVersion is added by ALTER table so its value might be 0.

pkg/statistics/handle/cache/statscache.go

@@ -328,6 +328,9 @@ func (s *StatsCacheImpl) Get(tableID int64) (*statistics.Table, bool) {
 
 // Put puts this table stats into the cache.
 func (s *StatsCacheImpl) Put(id int64, t *statistics.Table) {
+	statslogutil.StatsLogger().Info("stat cache put",
+		zap.Int64("tableID", id),
+		zap.Int("column number", t.ColNum()))
 	s.Load().put(id, t)
 }
 

pkg/statistics/handle/storage/read.go

@@ -400,6 +400,9 @@ func columnStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *stati
 		if histID != colInfo.ID {
 			continue
 		}
+		statslogutil.StatsLogger().Info("stat cache map insert col 4",
+			zap.Int64("tableID", table.PhysicalID),
+			zap.Int64("colID", histID))
 		table.ColAndIdxExistenceMap.InsertCol(histID, statsVer != statistics.Version0 || distinct > 0 || nullCount > 0)
 		// All the objects in the table shares the same stats version.
 		// Update here.

pkg/statistics/handle/syncload/stats_syncload.go

@@ -594,13 +594,19 @@ func (s *statsSyncLoad) updateCachedItem(item model.TableItemID, colHist *statis
 
 		// If the column is analyzed we refresh the map for the possible change.
 		if colHist.StatsAvailable() {
+			statslogutil.StatsLogger().Info("stat cache map insert col 5",
+				zap.Int64("tableID", tbl.PhysicalID),
+				zap.Int64("colID", item.ID))
 			tbl.ColAndIdxExistenceMap.InsertCol(item.ID, true)
 		}
 		// All the objects shares the same stats version. Update it here.
 		if colHist.StatsVer != statistics.Version0 {
 			tbl.StatsVer = statistics.Version0
 		}
 		// we have to refresh the map for the possible change to ensure that the map information is not missing.
+		statslogutil.StatsLogger().Info("stat cache map insert col 6",
+			zap.Int64("tableID", tbl.PhysicalID),
+			zap.Int64("colID", item.ID))
 		tbl.ColAndIdxExistenceMap.InsertCol(item.ID, colHist.StatsAvailable())
 	} else if item.IsIndex && idxHist != nil {
 		index := tbl.GetIdx(item.ID)

pkg/statistics/table.go

@@ -25,9 +25,11 @@ import (
 	"github.com/pingcap/tidb/pkg/meta/model"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
 	"github.com/pingcap/tidb/pkg/planner/planctx"
+	statslogutil "github.com/pingcap/tidb/pkg/statistics/handle/logutil"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/ranger"
 	"go.uber.org/atomic"
+	"go.uber.org/zap"
 )
 
 const (
@@ -1096,6 +1098,9 @@ func PseudoTable(tblInfo *model.TableInfo, allowTriggerLoading bool, allowFillHi
 		// We would not collect stats for the hidden column and we won't use the hidden column to estimate.
 		// Thus we don't create pseudo stats for it.
 		if col.State == model.StatePublic && !col.Hidden {
+			statslogutil.StatsLogger().Info("stat cache map insert col 1",
+				zap.Int64("tableID", tblInfo.ID),
+				zap.Int64("colID", col.ID))
 			t.ColAndIdxExistenceMap.InsertCol(col.ID, false)
 			if allowFillHistMeta {
 				t.columns[col.ID] = &Column{