Change cfs_fragmentation function

knizhnik · knizhnik · commit 7ab0ef5e5c0f · 2016-11-24T18:11:01.000+03:00
diff --git a/doc/src/sgml/cfs.sgml b/doc/src/sgml/cfs.sgml
@@ -308,7 +308,7 @@
        As it was mentioned before, CFS always appends updated blocks to the end of the compressed file. So physical size of the file
        can be greater than used size in this file. I.e. CFS file is fragmented and defragmentation is periodically performed by CFS
        garbage collector. <varname>cfs_fragmentation(relation)</varname> functions returns average fragmentation of relation files.
-       It is calculated as rum of physical sizes of the files divided by sum of used size of the files. 
+       It is calculated as sum of physical sizes of the files minus sum of used size of the files divided by sum of physical sizes of the files. 
      </para>
  
      <para>
diff --git a/src/backend/storage/file/cfs.c b/src/backend/storage/file/cfs.c
@@ -1064,7 +1064,7 @@ Datum cfs_fragmentation(PG_FUNCTION_ARGS)
 		pfree(map_path);
 		relation_close(rel, AccessShareLock);
 	}
-	PG_RETURN_FLOAT8((double)physSize/usedSize);
+	PG_RETURN_FLOAT8((double)(physSize - usedSize)/physSize);
 }
 
 Datum cfs_gc_activity_processed_bytes(PG_FUNCTION_ARGS)

Original file line number	Diff line number	Diff line change
`@@ -1064,7 +1064,7 @@ Datum cfs_fragmentation(PG_FUNCTION_ARGS)`
`1064`	`1064`	`pfree(map_path);`
`1065`	`1065`	`relation_close(rel, AccessShareLock);`
`1066`	`1066`	`}`
`1067`		`- PG_RETURN_FLOAT8((double)physSize/usedSize);`
	`1067`	`+ PG_RETURN_FLOAT8((double)(physSize - usedSize)/physSize);`
`1068`	`1068`	`}`
`1069`	`1069`
`1070`	`1070`	`Datum cfs_gc_activity_processed_bytes(PG_FUNCTION_ARGS)`