Re: Are left joins more efficient?

Dennis-- You might get a more authoritative answer from the mysql "general discussion" list at: http://lists.mysql.com --John On Monday 25 August 2003 12:59 pm, anachronism@mengelt.com wrote: > Hello, > > I program for a website that gets massive loads of > traffic. Optimisation has become an important issue > lately. > > At the moment, all queries on the website follow the same > format when joining tables: > SELECT * FROM table1,table2 WHERE table1.id=table2.id; > > My question is, would this format be more efficient? > SELECT * FROM table1 LEFT JOIN table2 ON > table1.id=table2.id; > > Over the last couple of years I have read and heard two > different answers. Years ago it was said that doing Left > Joins are faster and more efficient. But with recent > updates to MySQL I have read that both queries are broken > down and optimised the same way by MySQL. > > Any thoughts? I havn't come across any comparisons on the > web, so any answers would be appreciated. > > (couldn't find any mysql specific groups so i'm posting > in the next best thing!) > > Thanks > > -Dennis