Hi all: I'm trying to create a functional index into column position of token table (see below). I want to make something like: CREATE INDEX token_position_func ON token (position+1); but I get: test=# CREATE INDEX token_position_func test-# ON token (position+1); ERROR: syntax error at or near "+" LINE 2: ON token (position+1); I read that I can do "ON function(column)" but, is there a built-in function in PostgreSQL to do what I want (add one to the value) or have i to build one to make this simple calculation? CREATE TABLE doc( id INT, editorial VARCHAR, CONSTRAINT doc_pk PRIMARY KEY (id) ); CREATE TABLE token ( id INT, id_doc INT, token VARCHAR, position INT, CONSTRAINT foreign_doc FOREIGN KEY (id_do) REFERENCES doc (identificador) ); Regards, Mario Barcala