What are the different types of indexes in SQL?

What are the different types of indexes in SQL?

In SQL, the main types of indexes are: B-tree indexes, bitmap indexes, unique indexes, and full-text indexes. Would you like to know more about any specific type?

Can you explain B-tree indexes?

B-tree indexes are the most common type of index in SQL. They maintain a balanced tree structure, allowing for efficient data retrieval. They are particularly useful for range queries.

What about bitmap indexes?

Bitmap indexes are used for columns with a low cardinality, meaning they have a limited number of distinct values. They use bitmaps to represent the presence of values, making them efficient for certain types of queries.

Are unique indexes different from regular indexes?

Yes, unique indexes ensure that all values in the indexed column are distinct. This is often used to enforce primary key constraints.

How do full-text indexes work?

Full-text indexes allow for efficient searching of text data. They enable complex queries like searching for words or phrases within large text fields.