Indexálási

Indexálási refers to the process of creating an index for a database or a search engine. An index is a data structure that improves the speed of data retrieval operations on a database table or document collection. Without an index, a database must scan every row in a table to find the required information, which can be very slow for large datasets.

The most common type of index is a B-tree index. In a B-tree index, data is organized in a tree-like structure where each node contains a set of keys and pointers to child nodes. This structure allows for efficient searching, insertion, and deletion of data. Other types of indexes include hash indexes, which use a hash function to map keys to storage locations, and full-text indexes, which are designed for searching within text documents.

Creating an index involves analyzing the data and determining which columns or fields are frequently used in search queries or join operations. These fields are then added to the index. Maintaining indexes requires additional storage space and can slow down data modification operations, such as inserts, updates, and deletes, because the index must also be updated. Therefore, it is important to carefully consider which indexes to create and to balance the benefits of faster retrieval against the costs of maintenance.