What are the differences between various index types in databases?

What are the differences between various index types in databases?

There are several types of indexes in databases, including B-tree, hash, and bitmap indexes. B-tree indexes are great for range queries, while hash indexes are efficient for equality comparisons. Bitmap indexes are useful for columns with a limited number of distinct values.

Can you explain when to use a B-tree index over a hash index?

Sure! Use a B-tree index when you need to perform range queries or when the data is frequently updated. Hash indexes are best for equality searches where the data is static.

What about bitmap indexes? When should I use them?

Bitmap indexes are ideal for columns with low cardinality, meaning they have a small number of distinct values. They're particularly useful in data warehousing scenarios where complex queries are common.

Are there any downsides to using bitmap indexes?

Yes, bitmap indexes can consume a lot of space and may not perform well with high cardinality columns or frequent updates, as they need to be rebuilt.