This article addresses the importance of TempDB, while also underlying its features which can be used for making performance Improvements starkly noticeable in TempDB.
TempDB is a global database resource which is accessible to every user who is connected to the SQL Server instance. Most operations within tempdb are unlogged, which enables transactions to easily roll back. A new tempdb is created every time a user starts his/her SQL Server, so that system is always starting with a fresh copy of the database. These temporary tables and their stored procedures are automatically dropped when the user disconnects with the system. Tempdb doesn’t allow backup or restoration operations so ensure to save their important documents.
Every Temporary table is stored in tempdb for the duration till the time the connection is dropped (and for global temp cases it stores the data which was entered by the last connection till it was dropped). Users can also (and it is also an ideal practice to follow) manually drop their table when they have finished using it by tagging it with the drop table statement, which helps them in identifying it in the future.
TempDB also comes in handy at miscellaneous occasions, when user’s server or connection drops without any notice. Most organizations follow these properties properly in order to protect their data from getting lost in case they encounter a corrupt mdf file. However, it also helps in saving your system memory by preventing temporary files from getting saved permanently on your computer.
Performance Improvements in TempDB
• There is a good chance that some Temporary tables along its variables might be cached completely. It is important to note that caching allows dropped operations to initiate and create a given number of temporary objects which execute quickly.
• By improving the latching protocol of an Allocation page users can reduce the number of updates latches which are being used in the system.
• Logging overhead of tempdb is also reduced. This will automatically reduce tempdb log files, disk input/output bandwidth consumption.
• Setup can add multiple tempdb files in a database during the installation of a new instance. Users can accomplish this task by using the new UI control for input in the section Configuration settings for database engine with a command line input /SQLTEMPDBFILECOUNT. Essentially this setup will insert as many as tempdb files since the CPU can count or just 8; the lower value will come to play.
• When there are several tempdb related data files in a system, all files auto grow together at the same time, with the equal amount based on the applied growth settings.
• Tempdb uses uniform extents for all allocations. Users won’t require Trace flag 1118 after making these changes.
Users can create temporary objects anytime in tempdb without taking the permission of the administrator. However, these Users will only be able to access their own object, unless of course they receive or get additional permissions. Thankfully it is possible for the user to revoke the connection permission to a tempdb from preventing a user from operating through tempdb, but this should be avoided as some routine operation might require the usage of tempdb
Victor Simon is a data recovery expert in DataNumen, Inc., which is the world leader in data recovery technologies, including access recovery and sql recovery software products. For more information visit www.datanumen.com