Hi I am newbie so this problem may be too simple to be asked.please help me if any new thing to be added in following: I want to use user defined data type in User_Type(n) way.... I created data type IndChar The c functions are: /* Definaton of Data Type) */ typedef struct IndChar { int32 len; char c_in_str[1]; }IndChar; then i defined input & output functions. Input: Datum indcharin(PG_FUNCTION_ARGS); Output: Datum indcharout(PG_FUNCTION_ARGS); then i created a function of the same name(i.e. IndChar) as Datum indchar(PG_FUNCTION_ARGS);//for applying indchar(n) form i.e.fixed length and i created it using: create function indchar(IndChar, integer) returns IndChar language C as 'Path for indchar.so file' immutable strict; after these i created data type using: create type indchar (input = indcharin, output = indcharout, internallength = variable, storage = extended); the type is created... when i use it in Creating Table: create table temp (name IndChar(20)); it gives error at character '( '..... please tell me why it is giving such error... if some steps needed to alter or add tell me... thanx in advance Vinay jain ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match