Record Indexing

FIX messages are stored in a hierarchy of records, and cross-referenced using index columns.

Index columns have a long type, and are located at the end of the stream.

Records in the main stream have only one index. Child records have two indexes, the first of which must have the same value as the parent record. Descendant records at the next level have three indexes, the first two of which must have the same value as their parent record, and so on.