pub fn call(name: &str, args: &[Cell]) -> Option<Result<Cell, String>>Expand description
A pg_catalog function, applied to the arguments a row produced.
None means this catalogue has no function of that name, and the caller refuses it by name
— the same rule as Rel::missing, and for the same reason: psql writes these calls into
queries it expects to work, so one that silently answered NULL would produce a \d that is
wrong rather than one that says what it could not do.
Every one of them is a constant or a lookup. There is nothing to compute because there is nothing behind them: no roles, no search path, no defaults, no ACLs.