By using the nomenclature #localtable or ##globaltable SQL Server knows to create a table in TempDB. If you use a local temp table, it is only available for your current session.

I need to select some data (surprise) from several tables in a linked database which is running SQL Server 2000.Now the resulting data set will be about 10,000 records taken from ~ 8 tables.I can ...

Both examples are relevant to both DBs. The first example is what I'm trying to do: combine the contents of two tables using a subquery. This works fine in SQL Server but not in MySQL.