Use a table delete strategy to specify whether to compare data before deleting it and to select options for accessing tables.
Refer to the following table for information about the delete options and their potential results.
| Database | PK Index | Compare Never for table? | Actions or Delete File? | Key Lookup Limit | Delete processing with default Access Method | Expected result | Risks, Warnings, and Comments |
|---|---|---|---|---|---|---|---|
| DB2®, Oracle, or Teradata1 | non-unique index | Yes | No | N/A | Array delete used | All rows deleted | Additional rows with same PK can be deleted. |
| DB2, Oracle, or Teradata1 | non-unique index | Yes | Yes | N/A | Cursor controlled individual Primary Key delete | All rows deleted | Wrong rows with same PK can be deleted. |
| NOT DB2, Oracle, or Teradata | non-unique index | Yes | No | >1 | Multiple key delete | All rows deleted | Additional rows with same PK can be deleted. |
| NOT DB2, Oracle, or Teradata | non-unique index | Yes | No | =1 | Individual Primary Key delete – NOT cursor controlled | Only first row in the duplicate Primary Key table is deleted; other rows with the same PK marked "Not Found". | Additional rows with same PK can be deleted. |
| NOT DB2, Oracle, or Teradata | non-unique index | Yes | Yes | N/A | Cursor controlled individual Primary Key delete | All rows deleted | Wrong rows with the same PK can be deleted. |
| All databases | no index | Yes | Yes | N/A | Cursor controlled delete using table scans | All rows deleted | Wrong rows with the same PK can be deleted. |
| All databases | no index | Yes | No | N/A | Individual Primary Key delete–NOT cursor controlled | Only first row in the duplicate Primary Key table is deleted; other rows with the same PK marked "Not Found". | Additional rows with the same PK can be deleted. |