Commit 4fd3b1cf authored by unknown's avatar unknown
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Corrected fragmentation calculation to take into account that LQH creates "2... 

Corrected fragmentation calculation to take into account that LQH creates "2 fragments per fragment" in 4.1 and 5.0
+added some comments to ndb fragmentation calulation
parent 18dcc5dd

sql/ha_ndbcluster.cc

+10 −5
Original line number Diff line number Diff line
@@ -3513,18 +3513,23 @@ static void ndb_set_fragmentation(NDBTAB &tab, TABLE *form, uint pk_length) 
  uint no_fragments;

  {

#if MYSQL_VERSION_ID >= 50000

    uint acc_row_size= 25+2;

    uint acc_row_size= 25 + /*safety margin*/ 2;

#else

    uint acc_row_size= pk_length*4;

    /* add acc overhead */

    if (pk_length <= 8)

      acc_row_size+= 25+2;  /* main page will set the limit */

    else

      acc_row_size+= 4+4;   /* overflow page will set the limit */

    if (pk_length <= 8)  /* main page will set the limit */

      acc_row_size+= 25 + /*safety margin*/ 2;

    else                /* overflow page will set the limit */

      acc_row_size+= 4 + /*safety margin*/ 4;

#endif

    ulonglong acc_fragment_size= 512*1024*1024;

    ulonglong max_rows= form->max_rows;

#if MYSQL_VERSION_ID >= 50100

    no_fragments= ((max_rows*acc_row_size)/acc_fragment_size+1

		   +1/*correct rounding*/)/2;

#else

    no_fragments= (max_rows*acc_row_size)/acc_fragment_size+1;

#endif

  }

  {

    uint no_nodes= g_ndb_cluster_connection->no_db_nodes();