Purpose

Provide the MySQL server with position/offset information for last-read row.

Synopsis

Description

This is the position method.

position() is called after each call to rnd_next() if the data needs to be ordered. You can do something like the following to store the position: my_store_ptr(ref, ref_length, current_position);

The server uses ref to store data. ref_length in the above case is the size needed to store current_position. ref is just a byte array that the server will maintain. If you are using offsets to mark rows, then current_position should be the offset. If it is a primary key like in BDB, then it needs to be a primary key.

Called from filesort.cc, sql_select.cc, sql_delete.cc and sql_update.cc.

Parameters

Return Values

This function has no return values.

Usage

Return offset or retrieval key information for last row.