In what situations can the size of index data exceed the size of the table itself in a database?

The size of index data can exceed the size of the table itself in the following situations:

• A large number of indexes: if many indexes are created on the table, each one takes up additional space.
• Indexes on large or multi-column fields: for example, indexes on long strings, text fields, or composite indexes with multiple columns.
• High cardinality and fragmentation: when indexes contain many unique values and are inefficiently packed.
• Use of full-text or spatial indexes, which can be large.

For example, if a table contains a small number of rows but has several complex indexes, the total size of the indexes can exceed the size of the table data.