Specifies the algorithm used during a delete in a WD index.
0 – 3
0: The delete method is selected by the cost model. Cost model only selects either mid or large method for deletion.
1: Forces small method for deletion. Small method is useful when the number of rows being deleted is a very small percentage of the total number of rows in the table. Small delete can randomly access the index, causing cache thrashing with large datasets.
2: Forces large method for deletion. This algorithm scans the entire index searching for rows to delete. Large method is useful when the number of rows being deleted is a high percentage of the total number of rows in the table.
3: Forces mid method for deletion. Mid method is a variation of the small method that accesses the index in order and is generally faster than the small method.
DBA permissions are not required to set this option. Can be set temporary, for an individual connection, or for the PUBLIC group. Takes effect immediately.
Rows deleted
Index size
Width of index data type
Cardinality of index data
Available temporary cache
Machine related I/O and CPU characteristics
Available CPUs and threads