Double colon (::) notation in SQL

Question

Have picked up someone\'s code and this is a part of a where clause, anyone know what the double colon indicates?

b.date_completed >  a.dc::date + INTERVA         


        

Answer 1

It is probably a cast, converting a.dc to type date.

IBM Informix Dynamic Server (IDS) would work that way - but the INTERVAL notation at the end is not valid for IDS, so presumably this is in fact another DBMS (probably PostgreSQL).