Dudás József <dj1999@xxxxxxxxxxx> writes: > Yes! You are right! Now must me find out how to convert char* to numeric datum > and double to numeric datum and numeric datum to double :) If you have a char* you can usually call a types input function which is usally "type_in" or "typein" like: DirectFunctionCall1(type_in, str). However in the case of numeric you need to pass a couple extra parameters: DirectFunctionCall3(numeric_in, str, 0, -1 + VARHDRSZ) To convert to a float8 datum you would use DirectFunctionCall1(numeric_float,num). To convert from a Postgres float8 datum to an actual double you can just call the macros DatumGetFloat8 and Float8GetDatum. This makes your code depend on the internal representation of float8 as a C double but it's better than the alternative. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com