The mi_tab_setniorows() accessor function
The mi_tab_setniorows() function indicates that the access method can handle more than one row per call and the number of rows for which the database server should allocate memory.
Syntax
mi_integer mi_tab_setniorows(MI_AM_TABLE_DESC *tableDesc,
mi_integer nrows)- tableDesc
- Points to the index descriptor.
- nrows
- Specifies the maximum number of rows that am_getnext or am_insert processes.
Usage
The access method must call this function in either am_open or am_beginscan. Multiple calls to mi_tab_setniorows() during the execution of a single statement causes an exception to be raised.
A
secondary access method can set up a multiple-row area in shared memory
for use in one or both of the following purpose functions:
- The database server can place multiple entries in shared memory that the am_insert purpose function retrieves and writes to disk.
- The am_getnext purpose function can fetch multiple rows into shared memory in response to a query.
Return values
The integer indicates the actual number of rows for which the database server allocates memory. Currently, the return value equals nrows. A zero or negative return value indicates an error.