In reality, you better off manipulating the MyISAM tables via SQL. However, if you really are that adventurous about low-level reads of MyISAM tables, I have a crazy suggestion for you !!!
The old MySQL book used as reference to MySQL 3.23/4.0 describes manipulating a MyISAM table with an API that reminds me so much of manipulating DBF files via the DBASE/Clipper/FoxPro programming language. The book is called "MySQL Reference Manual" (ISBN 0-596-00265-3 ,Published June 2002) http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=0-596-00265-3 It was Chapter 6, pages 512,513 Section 6.4.2 HANDLER Syntax. This same information appears at the following URLs: http://dev.mysql.com/doc/refman/5.5/en/handler.html http://download.oracle.com/docs/cd/E17952_01/refman-5.0-en/handler.html Keep mind that this is a read-only MyISAM API. No low-level writes are available with that API. If you need to edit the MyISAM table structure, you should definitely used ALTER TABLE. However, if you really are that adventurous about table structure manipulation of MyISAM tables, I have a crazy suggestion for you !!! A more recent book, called "High Performance MySQL, Second Edition" (ISBN 0-0596-10171-8, Published June 2008) http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=0-596-10171-8 has a section "Speeding up ALTER TABLE" on Pages 146-149 on how to doctor the .MYI file to add new columns and the "gotchas" in doing it that way. If you want to writes and updated to column data in a MyISAM table, I have no crazy suggestions except one : Download the C source code for the MyISAM storage engine, study it, and have fun with it. If you just need faster write performance on MyISAM tables, use one or both of the following: 1) INSERT DELAYED for a single row (be prepared to suffer up to one second of data loss in the event of a crash) 2) LOAD DATA INFILE for bulk loading of data (please set bulk_insert_buffer_size to something like 512M) 3) More suggestions at http://kevin.vanzonneveld.net/techblog/article/improve_mysql_insert_performance/ I hope these ramblings of mine helped. Please write back to the MySQL Lists and let us all know what you tried and if it worked. Have a good day !!! Rolando A. Edwards MySQL DBA (SCMDBA) 155 Avenue of the Americas, Fifth Floor New York, NY 10013 212-625-5307 (Work) 201-660-3221 (Cell) AIM & Skype : RolandoLogicWorx redwa...@logicworks.net http://www.linkedin.com/in/rolandoedwards -----Original Message----- From: Adarsh Sharma [mailto:adarsh.sha...@orkash.com] Sent: Sunday, January 09, 2011 11:14 PM To: mysql@lists.mysql.com Subject: Reading .MYD file of Mysql Tables Dear all, I am facing a issue which should be resolved by editing .MYD file of a Table. I know there are 3 files foe a MyISAM table in Mysql but i want to read and edit some changes in .MYD file. If it is possible , Can anyone PLease tell me the way to do this. Thanks & Regards Adarsh Sharma -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=redwa...@logicworks.net -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
