How do SQLite indexes work?

How does SQLite indexing work?

Whenever you create an index, SQLite creates a B-tree structure to hold the index data. The index contains data from the columns that you specify in the index and the corresponding rowid value. This helps SQLite quickly locate the row based on the values of the indexed columns.

Are primary keys automatically indexed SQLite?

An INTEGER PRIMARY KEY becomes the actual key used in the B-tree that stores your table. So no index is required for efficient operation. You should always omit indexes on PRIMARY KEY columns, regardless of the type. The best case for an index on a PRIMARY KEY is that it will be a no-op.

When should indexes be avoided SQLite?

Indexes should not be used on columns that return a high percentage of data rows when used as a filter condition in a query's WHERE clause. For instance, you would not have an entry for the word "the" or "and" in the index of a book.

What is SQLite auto index?

The INDEXED BY phrase forces the SQLite query planner to use a particular named index on a DELETE, SELECT, or UPDATE statement. The INDEXED BY phrase is an SQLite extension and is not portable to other SQL database engines.