I have large "fact" table, in which there are much ids (that are in fact
"foreign keys" but as long as I use MyISAM engine them are not
technically). So when I try to join another table (that contains text
descriptions for each id from one of "fact" columns, so it has two
fields (id (PK) and name)) in my query, it chooses strange execution
plan.
When I do simple join, it uses my second table as first, scanning it and
joining records from "fact" table by their "foreign" key.
If I do straight join or left outer join it makes full scan of second
table, ignorig its pk ("use key(primary)" doesn't help).
I guess, standart execution plan for all such cases must be scan of
first table joining all other description tables by their PKs.Forgot to say that query fetches all data from "fact" table, grouping by some columns. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
