ne 23. 11. 2025 v 1:45 odesílatel Tom Lane <tgl@sss.pgh.pa.us> napsal:
Paul A Jungwirth <pj@illuminatedcomputing.com> writes: > The reason for supporting more than SQL functions is to let you > construct the query dynamically, e.g. with user-supplied table/column > names, or to only include some expensive filters if needed. This would > be great for building functions that implement temporal > outer/semi/antijoin. Another use-case I personally have, which I think > is quite common, is building "parameterized views" for permissions > checks, e.g. visible_sales(user). In that case we may only need to > include certain joins if the user belongs to certain roles (e.g. a > third-party sales rep).
I went through this again, and committed it with a bunch of mostly-cosmetic changes. In particular, it seemed like talking about inlining "set-returning functions" is no longer really on-point, since this mechanism is perfectly capable of inlining non-SRFs. (The reason we haven't done that for SQL functions is mainly that we didn't feel like doing the analysis necessary to prove that a SELECT will return exactly one row, which would be necessary to maintain semantic equivalence for a non-SRF after inlining. The easy cases of that, such as "SELECT expression", are already sufficiently handled by regular inlining.)
So after some thought I renamed inline_set_returning_function to inline_function_in_from, and made a bunch of other changes in names and comments to line up with that.
Thanks for working on this! I know it's been a long slog.
I checked this patch, and I think so using the body of the function foo_from_bar is very confusing.
If I understand this patch and functionality, then the function is never executed (when the support function has support for SupportRequestInlineInFrom).
+CREATE FUNCTION test_inline_in_from_support_func(internal) + RETURNS internal + AS :'regresslib', 'test_inline_in_from_support_func' + LANGUAGE C STRICT; +CREATE FUNCTION foo_from_bar(colname TEXT, tablename TEXT, filter TEXT) +RETURNS SETOF TEXT +LANGUAGE plpgsql +AS $function$ +DECLARE + sql TEXT; +BEGIN + sql := format('SELECT %I::text FROM %I', colname, tablename); + IF filter IS NOT NULL THEN + sql := CONCAT(sql, format(' WHERE %I::text = $1', colname)); + END IF; + RETURN QUERY EXECUTE sql USING filter; +END; +$function$ STABLE;
More correct form should be
BEGIN
RAISE EXCEPTION 'halt - should not be executed directly';
