A temporary table is a special type of table that is automatically deleted when it is no longer used. Temporary tables have many of the same characteristics as permanent tables and are typically used as work tables that contain intermediate results.
You designate a table as temporary in SQL Server by prefacing the table name with a single pound sign (
#) or two pound signs (
##). Temporary tables are created in
tempdb; if a temporary table is not explicitly dropped, it is dropped when the session that created it ends or the stored procedure it was created in finishes execution.
If a table name is prefaced with a single pound sign (for example,
#table1), it is a private temporary table, available only to the session that ...