Expression Index
Introduction Expression Index is an extremely powerful feature of PostgreSQL, which can be used for any data type (such as text, numbers, time, arrays and more) as long as the result of the expression returns a Deterministic value You can use Expression Index for all index types ( B-Tree , Hash , GIN , GiST and more) as long as the expression you write in the CREATE INDEX command returns a data type that the Index type supports for processing The nature of Expression Index is that instead of indexing on the original column value, Postgres precomputes the result of the function or expression as soon as you INSERT/UPDATE and saves the result directly into the Index file Characteristics After creating an Expression Index, when using a query, you must write it exactly like the expression in the Index, otherwise the index will not work Every time a row of data is modified, Postgres must run that function or expression to get the result to create the Index. Therefore, avoid using function...