I found in the Debuger cid (RecordSet)

Still working with FieldSchema, in the Debuger, I found an entry called cid.

What the hell this can be ?

To see that, run the application with a Break point set after rs = db.FieldSchema(MyTable),
then click in rs and read. You will get:

From the Language Reference: FieldSchema typically returns a RecordSet with these columns: ColumnName: A String that is the Name of the column. FieldType: An Integer that describes the type of the column (refer to the table below). IsPrimary: A Boolean that indicates if the column is part of the Primary Key. NotNull: A Boolean that indicates if the column can be set to NULL. Length: An Integer that describes the length of the field (for some text fields) or the precision of numeric data (for some numeric fields).

CID=column Identifier… not something you really need to care about