Key descriptor
The key descriptor, or MI_AM_KEY_DESC structure, identifies the keys and operator class for an index.
The following functions extract information from the key
descriptor.
| Accessor function | Return value |
|---|---|
| mi_key_funcid() | The routine identifier of the UDR that determines the value of a specified key in a functional index |
| mi_key_nkeys() | The number of columns in an index key |
| mi_key_opclass(), mi_key_opclass_name() | The identifier or name of the operator class for a specified column of the index key |
| mi_key_opclass_strat() | The name of one strategy function Typically, an access method calls the mi_qual_funcid() function to obtain the routine identifier and does not use mi_key_opclass_strat(). |
| mi_key_opclass_nsupt() | The number of support functions |
| mi_key_opclass_supt() | The name of one support function For an example of how to use the function names to execute the function, see Obtaining the routine identifier. |