GiST (Generalized Search Tree)

• A GiST index is a template indexing structure that allows domain experts to adhere to an interface and index custom data types.
• Must implement the following methods- consistent, union, compress, decompress, penalty, picksplit, same.
• Writes to GiST indexes lock the whole index. Writes to btree indexes only lock the affected index page.
• Knowledge of C is required to write custom GiST indexes.