public int getSize() {
      //facilitate testing only. In production we won't use tableSizeMap at all.
      if (tableSizeMap != null) {
        String tblKey = CacheUtils.buildTableKey(this.t.getCatName(), this.t.getDbName(), this.t.getTableName());
        if (tableSizeMap.containsKey(tblKey)) {
          return tableSizeMap.get(tblKey);
        }
      }
      if (sizeEstimators == null) {
        return 0;
      }
      int membersSize = 0;
      for(MemberName mn : MemberName.values()) {
        membersSize += this.memberObjectsSize[mn.ordinal()];
      }
      return otherSize + membersSize;
    }
this flag is used to validate/invalidate cached constraints snapshot.
All table constraints are update successfully either via updater thread or
while create_table_with_constraint api then it is set to true else
false and redirect all the call to raw metastore.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/cache/SharedCache.java