A table variable can be created at the beginning of a stored procedure and referenced throughout since everything declared within the stored procedure remains in scope throughout the lifetime of the stored procedure execution. Once a GO command is issued from Query Analyzer, the table variable is no longer in scope for any SQL statement issued afterwards. How to Use: INSERT INTO PolicyId, LastName PolicyId INT IDENTITY(1,1) PRIMARY KEY NOT NULL,Įxisting in memory for the duration of a single T-SQL batch, table variables are declared using syntax similar to local variable declaration. Global temporary tables are created using a double pound (#) sign and are visible across multiple connections and users and are automatically dropped when all SQL sessions stop referencing the global temporary table. Local temporary tables are created using a single pound (#) sign and are visible to a single connection and automatically dropped when that connection ends. There are 2 types of temporary tables, local and global. If you're tasked with ensuring SQL queries and stored procedures are highly optimized for performance then you should consider experimenting with temporary tables, table variables, and derived tables. If your goal as a developer is simply to provide an environment for the storage and retrieval of data, then utilizing physical tables will work just fine.
Aside from the physical tables that reside in a database, there are a several other types of tables that database developers should become intimately familiar with.
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