Should I use temp table or table variable?

As far as performance is concerned table variables are useful with small amounts of data (like only a few rows). Otherwise a SQL Server temp table is useful when sifting through large amounts of data. So for most scripts you will most likely see the use of a SQL Server temp table as opposed to a table variable.

What is the difference between a temp table and a table variable?

A Temp table is easy to create and back up data. Table variable involves the effort when you usually create the normal tables. Table variable will store in the physical memory for some of the data, then later when the size increases it will be moved to the tempdb. …

Is temp table faster than table variable?

Whereas, a Temporary table (#temp) is created in the tempdb database. So table variable is faster then temporary table. ⇒ Temporary tables are allowed CREATE INDEXes whereas, Table variables aren’t allowed CREATE INDEX instead they can have index by using Primary Key or Unique Constraint.

When would you use a temp table?

The best time to use temporary tables are when you need to store information within SQL server for use over a number of SQL transactions. Like a normal table, you’ll create it, interact with it (insert/update/delete) and when you are done, you’ll drop it.

What is the difference between common table expression CTE vs temp table?

This biggest difference is that a CTE can only be used in the current query scope whereas a temporary table or table variable can exist for the entire duration of the session allowing you to perform many different DML operations against them.

Why do we use temp table in SQL?

A temporary table exist solely for storing data within a session. The best time to use temporary tables are when you need to store information within SQL server for use over a number of SQL transactions. If you create a temporary table in one session and log out, it will not be there when you log back in.

Are temp tables faster?

The reason, temp tables are faster in loading data as they are created in the tempdb and the logging works very differently for temp tables. All the data modifications are not logged in the log file the way they are logged in the regular table, hence the operation with the Temp tables are faster.

What is the advantage of using a temporary table instead of a heap table?

They use indexes which make them faster. Temporary table : The temporary tables could be very useful in some cases to keep temporary data. Temporary table is that they will be deleted when the current client session terminates.

Which is better cursor or temp table?

So if you can use set-based operations to fill and use your temporary tables, I would prefer that method over cursors every time. Temp tables can be fine or bad depending on the data amount and what you are doing with them. They are not generally a replacement for a cursor.

When to use temp table vs table variable?

Otherwise a SQL Server temp table is useful when sifting through large amounts of data. So for most scripts you will most likely see the use of a SQL Server temp table as opposed to a table variable. Not to say that one is more useful than the other, it’s just you have to choose the right tool for the job.

Where are table variables located in the database?

Many believe that table variables exist only in memory, but that is simply not true. They reside in the tempdb database much like local SQL Server temp tables. Also like local SQL temp tables, table variables are accessible only within the session that created them.

Where are temp tables created in SQL Server?

SQL temp tables are created in the tempdb database. A local SQL Server temp table is only visible to the current session. It cannot be seen or used by processes or queries outside of the session it is declared in.

Why does the table variable outperform the temporary table?

When deleting rows based on the primary key the table variable outperforms the temporary table. As with the SQL Profiler results of the INSERT statement this is probably due to the fact that an extra index has to be updated.