Ignore already fully compressed columnstore indexes

Author: sergiisyrovatchenko

Server/Query.cs

@@ -585,9 +585,9 @@ CROSS APPLY sys.dm_db_index_physical_stats(@DBID, i.ObjectID, i.IndexID, i.Parti
 FROM (
     SELECT IndexID          = [index_id]
          , PartitionNumber  = [partition_number]
-         , PagesCount       = SUM([size_in_bytes]) / 8192
+         , PagesCount       = ISNULL(SUM([size_in_bytes]), 0) / 8192
          , UnusedPagesCount = ISNULL(SUM(CASE WHEN [state] = 1 THEN [size_in_bytes] END), 0) / 8192
-         , Fragmentation    = CAST(ISNULL(SUM(CASE WHEN [state] = 1 THEN [size_in_bytes] END), 0) * 100. / SUM([size_in_bytes]) AS FLOAT)
+         , Fragmentation    = ISNULL(CAST(ISNULL(SUM(CASE WHEN [state] = 1 THEN [size_in_bytes] END), 0) * 100. / SUM([size_in_bytes]) AS FLOAT), 0)
     FROM sys.fn_column_store_row_groups(@ObjectID)
     GROUP BY [index_id]
            , [partition_number]

Server/QueryEngine.cs

@@ -469,7 +469,7 @@ public static void FindDublicateIndexes(List<Index> indexes) {
     }
 
     private static IndexOp CorrectIndexOp(IndexOp op, Index ix) {
-      if (op == IndexOp.NO_ACTION || op == IndexOp.IGNORE)
+      if (op == IndexOp.NO_ACTION || op == IndexOp.IGNORE || (ix.IsColumnstore && ix.Fragmentation == 0))
         return IndexOp.SKIP;
 
       if (ix.IndexType == IndexType.MISSING_INDEX)