UDR with ESQL/C questions

Jonathan Leffler wrote (it' only the last part): >(2) ESQL/C programs talk to the database over a connection. Trying > to embed an ESQL/C routine inside the database in a UDR therefore > doesn't work because your trying to use the client-side connection > code on the server-side of the database system. There are distinct > rules about what you can put into a UDR -- you'll need to read the > docs, the same as I need to read them. You're likely to use the > mi_* family of routines. I read the 'User Defined Routines' Document (V9.1) wich pointed me (for external routines) to the 'DataBlade API Programmers Manual' (V9.12). In there it says the ESQLC - header files are included to support ESQL/C as well as the mi_* routines. I thought this means using ESQL/C in UDR's should be possible. If I can not use ESQL/C in UDR's what does this mean ? Another question of mine is the difference between the mi_open function for establishing connections to the database server and the connection needed for ESQL/C routines ? Thanks Ilona