Database index

A database index is a data structure used to quickly locate records within a database. It is an ordered list of keys that purpose to decrease the number of data entries examined when searching a database for a specific record. A well-defined index can drastically reduce the time to search a database and increase its scalability.

When a query is made to a database, a search for the indexed term(s) is performed and the index is used to locate the requested records at lightning speed compared to a database scan, making database indexing useful for large tables that need to be queried repeatedly. Indexing is used on database columns that are frequently searched and/or updated.

Database indexing can be static or dynamic. Static indexes are based on data stored in the database and must be manually created or dropped, while dynamic indexes are automatically updated depending on the data stored in the database.

Creating a database index requires a series of steps, including selecting an appropriate index type and a set of columns, and optimizing the index for faster search results. Additionally, database index maintenance is necessary to ensure the index is up-to-date and does not limit the scalability of the database.

Indexes are an essential component of database design, and help ensure that the database is optimized and performs efficiently. Improper indexing can lead to poor query performance and load on the system. Indexes should be used when adding or querying large amounts of data on a regular basis, in order to:

• Improve query performance
• Prevent lock contention
• Reduce disk and memory usage
• Eliminate unnecessary data
• Optimize data access

A database index is a powerful tool for increasing the speed and performance of a database query, reducing response times when searching large databases. Properly implemented, it can provide faster access to the data desired by the user.