File & Storage Cabinets

Database tuning describes a group of activities used to optimize and homogenize the performance of a database. more...

Home
Bedding
Furniture
Bedroom Furniture
Children's Furniture
Dining Room Furniture
Kitchen Furniture
Living Room, General...
Office
Bookcases
Computer Armoires
Computer Desks
File & Storage Cabinets
Office Chairs
Office Furniture Sets
Other Office Furniture
Traditional Desks
Home Decor
Miscellaneous
Patio & Grilling

It usually overlaps with query tuning, but refers to configuration of the database files, the database management system (DBMS), and the operating system and hardware the DBMS runs on.

The goal is to maximize use of system resources to perform work as efficiently and rapidly as possible. Most systems are designed to manage work efficiently, but it is possible to greatly improve performance by customizing settings and the configuration for the database and the DBMS being tuned.

I/O tuning

I/O tuning is placing database transaction logs, files associated with temporary work spaces, and table and index file storage to optimize and balance reads and writes against these files. I/O is generally the most expensive operation in database work, and is typically the first bottleneck in database performance encountered.

Hardware and software configuration of disk subsystems are examined: RAID levels and configuration, block and stripe size allocation, and the configuration of disks, controller cards, storage cabinets, and external storage systems such as a SAN. Transaction logs and temporary spaces are heavy consumers of I/O, and affect performance for all users of the database. Placing them appropriately is crucial.

Frequently joined tables and indexes are placed so that as they are requested from file storage, they can be retrieved in parallel from separate disks simultaneously. Frequently accessed tables and indexes are placed on separate disks to balance I/O and prevent read queuing.

DBMS tuning

DBMS tuning refers to tuning of the DBMS and the configuration of the memory and processing resources of the computer running the DBMS. This is typically done through configuring the DBMS, but the resources involved are shared with the host system.

Tuning the DBMS can involve setting the recovery interval (time needed to restore the state of data to a particular point in time), assigning parallelism (the breaking up of work from a single query into tasks assigned to different processing resources), and network protocols used to communicate with database consumers.

Memory is allocated for data, execution plans, procedure cache, and work space. It is much faster to access data in memory than data on storage, so maintaining a sizable cache of data makes activities perform faster. The same consideration is given to work space. Caching execution plans and procedures means that they are reused instead of recompiled when needed. It is important to take as much memory as possible, while leaving enough for other processes and the OS to use without excessive paging of memory to storage.

Read more at Wikipedia.org