Examples for changing table scheme from MAL/C

Hello Developers,

I need some help to understand monetdb kernel/sql structure.

Please, provide example code/paper or link for follow situation: I have a table (SQL), and I want to change structure of it (add/drop/rename/order column). I know, I can do it with SQL, but I need to view examples in MAL or C.

I want to write function like this:

int add_column(str schemaName, str tableName, str newColumnName) { // return 1 if column successfully created }

Before posting this message I saw the source code of SQL kernel and found some functions like sys_drop_column, mvc_create_column and others. But, I don't know how to execute these functions from my own user defined C/MAL function.