Keynote speech at Symposium on Emerging Trends in Database Technologies (ETDT), Pune Institute of Engineering and Technology, October 2004.

1. Trends in Graph Data Management and Mining Srinath Srinivasa IIIT Bangalore [email_address]

2. No data is an island…

4. Graph Data A graph G = (V,E) is a collection of nodes (vertices) and edges. A graph represents a “relationship structure” among different data elements. A graph database is a collection of different graphs representing different relationship structures.

5. Graph database versus Relational database A relational database maintains different instances of the same relationship structure (represented by its ER schema) A graph database maintains different relationship structures

11. Storing Graph Data Attributed Relational Graphs (ARGs) A B C D p q r s t r D A p C A t D B s C B q B A

13. Storing Graph Data A B C D p q r s t Maximum walks: A r D t B s C p A q B

15. Storing Graph Data Linear DFS Tree: (Example: Glide http://www.cs.nyu.edu/cs/faculty/shasha/papers/graphgrep/ ) A B C D p q r s t A%1 /p/ C /s/ B%1q /t/ D%1r

17. Storing Graph Data XML with IDREFS: A B C D <node id=“A”, adj=“C D”> <node id=“B”> <node id=“C”> </node> <node id=“D”> </node> </node> </node>

21. Structural Indexes GraphGrep (Guigno and Shasha 2002) Two index files: “ Fingerprint” file holding label-paths “ Path” file holding id-paths … paths from length 1 up to a maximum l p

22. Structural Indexes GraphGrep (Guigno and Shasha 2002) A B A D 1 2 3 4 G1 Database Fingerprint file 0 2 ABA 1 2 AAB 0 1 BD 1 1 AD 1 2 AB 0 2 AA G2 G1 Path

23. Structural Indexes GraphGrep (Guigno and Shasha 2002) A B A D 1 2 3 4 G1 Database Paths file {1-2-3, 3-2-1} ABA {1-3-2, 3-1-2} AAB {2-4} BD {1-4} AD {1-2, 3-2} AB {1-3, 3-1} AA G1 Path

25. Structural Indexes Hierarchical Conceptual Clusters (SUBDUE) (Jonyer, Cook, Holder 2001) Database Graph 1 Graph 2 Concept 1 Concept 2 Rest of Graph 1 Rest of Graph 2 Concept 1.1

36. gSpan A B A D p q r p 0 1 2 3 Sequence: (0,1,A,q,B)(1,2,B,r,A)(2,0,A,p,A)(1,3,B,p,A) Since a graph has many DFS trees, consider only the DFS tree which yields sequence with the least lexicographic value.

39. FBT A B C A B A C B Length-1 Walks AB, AB, BC, AC AB, AB, BC, AC

40. FBT A B C A B A C B Length-2 Walks ABA , ABC, BCA, BAC, ABA, ACB ABC, ACB, BCA, BAC, BAB , BAC

48. Thank You! For more interaction, contact me at [email_address]