CALL name ( [ argument ] [, ...] )
If the procedure has any output parameters, then a result row will be returned, containing the values of those parameters.
The name (optionally schema-qualified) of the procedure.
An argument expression for the procedure call.
Arguments can include parameter names, using the syntax name => value. This works the same as in ordinary function calls; see Section 4.3 for details.
Arguments must be supplied for all procedure parameters that lack defaults, including OUT parameters. However, arguments matching OUT parameters are not evaluated, so it's customary to just write NULL for them. (Writing something else for an OUT parameter might cause compatibility problems with future PostgreSQL versions.)
To call a function (not a procedure), use SELECT instead.
If CALL is executed in a transaction block, then the called procedure cannot execute transaction control statements. Transaction control statements are only allowed if CALL is executed in its own transaction.
PL/pgSQL handles output parameters in CALL commands differently; see Section 43.6.3.