From: ANIL YADAV Date: December 16 2009 4:11pm Subject: Re: MySQL index performance List-Archive: http://lists.mysql.com/innodb/12 Message-Id: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=00163630f9255f311a047adac276 --00163630f9255f311a047adac276 Content-Type: text/plain; charset=ISO-8859-1 Hello If we delete a index from a table, It will not increarse the select performance , Surely it will increase perfoemance for insert ,delete and Update. Also u will gain some space on disk also. Craete index but it must be useful some where, Don't make unnecesarry Index. Thanks & Regards ----------------------------- ANIL YADAV +91-9871047883 LinkedIn:-http://www.linkedin.com/in/anilyadav --------------------------------------------------------- "We judge ourselves by what we feel capable of doing, while others judge us by what we have already done." ---------------------------------------------------------- On Tue, Dec 15, 2009 at 4:59 PM, Antoine Noal wrote: > Hi > > I want to optimize my MySQL schema in order to increase performance of my > application. And I see several points that could be corrected but I am not > sure what would be the impacts and benefits. > > One example, MySQL Workbench create indexes for all foreign keys even on > many-to-many relationship table causing index duplication. > > Example : > table1 and table2 are linked by table3. > Table3 fields will look like this : > > table1_id > table2_id > > and indexes as follow : > PRIMARY(table1_id, table2_id) > FK_table1(table1_id) > FK_table2(table2_id) > > FK_table1 is not necessary. > > If I drop this index, when will I see benefits ? Only on inserts ? > I will certainly win few disk space too, but will it increase select > performance ? > > Of course, the storage engine used id InnoDB. > > Thank you for your help and sorry for my english. > --00163630f9255f311a047adac276--