collation conversion normal?

Question

Hi, The following explain extended let me know that MySQL is internally doing a lot of collation conversion like latin1 and _utf8.

(`mydb`.`node`.`status` = _latin1'1') and (`mydb`.`node`.`type` = _utf8'usernode') 
and (`mydb`.`node`.`uid` = `mydb`.`users`.`uid`) 
and (`mydb`.`usernode_list`.`uid` = _latin1'65484')

Is it normal? Will this slow down the query?

Answer 1

I don't think this is a problem as such. The conversion is only happening on what appear to be literal values from your query, so they should only happen once and it shouldn't affect performance. (Why it is feeling the need to coerce what appear to be integer literals I have no idea.)

Perhaps your connection is using a different character set to the one used in the database? For sanity it's best to use the same character set for both the connection and all the data.