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Problem Solutions

  




 

 

15.17.18. position

Purpose

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

Synopsis

virtual void position ( record);  
const byte *  record ;

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

  • record

Return Values

This function has no return values.

Usage

Return offset or retrieval key information for last row.


 
 
  Published under the terms of the GNU General Public License Design by Interspire