statistics: batch insert topn and bucket when saving table stats (#35326)
statistics: batch insert topn and bucket when saving table stats (#35326)

ref pingcap/tidb#35142
ngaut/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb,kyle-wang/tidb,kyle-wang/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb,ngaut/tidb,kyle-wang/tidb,kyle-wang/tidb,ngaut/tidb,pingcap/tidb,kyle-wang/tidb,kyle-wang/tidb,pingcap/tidb