Types of Indexes

There are different types of indexes that can be created on tables in a database, all of which serve the same goal—to improve database performance by expediting data retrieval. This hour discusses single-column indexes, composite indexes, and unique indexes.

Note

Indexes can be created during table creation in some implementations. Most implementations accommodate a command, aside from the CREATE TABLE command, used to create indexes. You must check your particular implementation for the exact syntax for the command, if any, that is available to create an index.

Single-Column Indexes

Indexing on a single column of a table is the simplest and most common manifestation of an index. Obviously, a single-column index is one that ...

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