Sequential Database

A sequence represents a collection of itemsets (or transactions) in a particular order. A sequence database is a collection of sequences and their sequence identifiers. An example of a geo-referenced transactional database is as follows:

Rules to create a sequence database:

• Items in an itemset have to be seperated by a tab space.

• Itemsets in a sequence are seperated using ‘-1’ as a seperator.

• Each sequence is represented as a line

• The sequence identifier, sid, is not needed to create a sequence database.

Format of a sequence:

>>> item1<sep>item2<sep>...<sep>itemA : item1<sep>item2<sep>...<sep>itemB : item1<sep>item2<sep>...<sep>itemC

Example:

>>> a b c d : a d e : a e f
    a b c : b d e : c d e
    a e f : c
    a e f : a c d : c e

• Sequential Frequent Pattern mining

• Geo-referenced Frequent Sequence Pattern mining