The mi_key_opclass_strat() accessor function

The mi_key_opclass_strat() function retrieves the name of an operator-class strategy function.

Syntax

mi_string* mi_key_opclass_strat(MI_AM_KEY_DESC *keyDesc,
   mi_integer keyNum,
   mi_integer strategyNum)

keyDesc: Points to the key descriptor.
keyNum: Specifies the column number of a key in a composite-key index or 0 for a single-key index.
strategyNum: Identifies the strategy function.

Usage

Each call to mi_key_opclass_strat() returns the name of one strategy function for one key column.

The strategyNum value for the first support function is 0. To determine the number of strategy functions that mi_key_opclass_strat() can return for a particular key column, call mi_key_opclass_nstrat(). To determine the maximum keyNum value, first call mi_key_nkeys().

The mi_key_opclass_strat() returns strategy function names in the order that the CREATE OPCLASS statement names them.

To obtain the name of a strategy function in a WHERE clause, the access method can call the mi_qual_funcname() access function instead of mi_key_opclass_strat().

Return values

The string contains the strategy function name.

A NULL-valued pointer indicates that the function arguments contain an invalid value for either keyNum or strategyNum.