# Information Integration (academic year 2014/2015)

This is one of the sections of the course Elective in Software and Services. The lectures of this section will be held in March-May 2015.

**For whom is this course.**This 3 credits course is actually one of the sections of the course http://www.dis.uniroma1.it/~santucci/Elective%20in%20Software%20and%20Se... for the students of the Master in Computer Engineering (School of Engineering) of Sapienza Università di Roma.

**Prerequisites.**A good knowledge of the fundamentals of Programming Structures, Programming Languages, Databases (SQL, relational data model, Entity-Relationship data model, conceptual and logical database design) and Database systems, as well as a basic knowledge of Mathematical Logic is required.

**Course goals.**Information integration is the problem of combining data residing at different sources, and providing the user with a unified view of these data. The problem of designing information integration systems is important in current real world applications, and is characterized by a number of issues that are interesting from both a theoretical and a practical point of view. In the last years, there has been a huge amount of research work on data integration, and a precise, clear picture of a systematic approach to such problem is now available. This section will present an overview of the research work carried out in the area of data integration, with emphasis on the theoretical results that are relevant for the development of information integration solutions. Special attention will be devoted to the following aspects: architectures for information integration, modeling an information integration application, ontology-based data access and integration, processing queries in information integration, data exchange, and reasoning on queries.

**News****January 4, 2016**The exam of the March/April 2016 session will be held on April 5, 2016 at 4pm.**May 26, 2015**The rules for the exam and the dates of the exams have been posted in this page (see below).

**Topics covered**- Architectures for information integration
- Distributed data management
- Data federation
- Data exchange and data warehousing
- ETL (Extraction, Transformation and Loading), data cleaning and data reconciliation
- Data integration
- Ontology-based data integration

**Teaching material**- Before the beginning of the lectures, students are invited to (re)study the basic notions of propositional and first-order logic. For this purpose, students may use the material they used in previous courses, or have a look at:
- Introduction to propositional logic (paper)
- Introduction to first-order logic (paper)
- FOL and conjunctive queries (from the material of "Metodi Formali per il Software e i Servizi", by Giuseppe De Giacomo)

- Before the beginning of the lectures, students are invited to (re)study the basic notions of propositional and first-order logic. For this purpose, students may use the material they used in previous courses, or have a look at:
**Slides**The lecture notes can be downloaded from the course page in Moodle

**Exams**The following are the rules for the exam. There are three possibilities for the exam:

- Study a tool for data integration or data federation, or data exchange, and then make a presentation (in English), where the characteristics of the tool are described, the position of the tool in the spectrum of information integration principles illustrated in the course, is discussed, and a demo of the tool is presented. For a picture of the available tools for data integration, the student should search on the web. Here is an incomplete list of possible tools: Karma, IBM Infosphere, Oracle data integrator, CloverETL, Pentaho, TEIID, Talend, Jitterbit, Adeptia, Open Refine etc.
- Choose a set of data sources with data relevant for a certain phenomenon (for example, data taken from open data published on-line, or data taken from a database or from an xls file known by the student), and develop a data integration or data exchange application using such data sources (and using any tool selected by the student). This work can be carried out in a group of at most two students.
- Study a paper on information integration, and then discuss the paper in a 15 minutes presentation (in English), again, including a part for positioning the work in the context of the spectrum of the principles illustrated in the course. Here is a (non exhaustive) list of papers that can be considered (use Google to find the papers and download them):
- 1. Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini, Moshe Y. Vardi.
*Rewriting of Regular Expressions and Regular Path Queries*. In J. Comput. Syst. Sci. 64(3):443-465, 2002 - 2. Alon Y. Levy, Alberto O. Mendelzon, Yehoshua Sagiv, Divesh Srivastava.
*Answering Queries Using Views*. PODS 1995: 95-104 - 3. Rachel Pottinger, Alon Halevy.
*MiniCon: A scalable algorithm for answering queries using views*.The VLDB Journal” The International Journal on Very Large Data Bases, Volume 10, Issue 2-3 (September 2001) - 4. Oliver M. Duschka, Michael R. Genesereth, Alon Y. Levy.
*Recursive Query Plans for Data Integration*. J. Log. Program. 43(1): 49-73 (2000) - 5. Philippe Adjiman, Philippe Chatalic, Francois Goasdou, Marie-Christine Rousset, Laurent Simon.
*Distributed Reasoning in a Peer-to-Peer Setting: Application to the Semantic Web.*Journal of Artificial Intelligence Research (JAIR) 25: 269-314 (2006) - 6. Xin Luna Dong, Alon Y. Halevy, Cong Yu.
*Data integration with uncertainty*. VLDB J. 18(2): 469-500 (2009) - 7. Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wang Chiew Tan.
*Composing schema mappings: Second-order dependencies to the rescue*. ACM Trans. Database Syst. 30(4): 994-1055 (2005) - 8. Andrea Calì, Domenico Lembo, Riccardo Rosati.
*On the decidability and complexity of query answering over inconsistent and incomplete databases*. PODS 2003: 260-271 - 9. Jens Bleiholder, Felix Naumann.
*Data fusion*. ACM Comput. Surv. 41(1): (2008) - 10. Marcelo Arenas, Leopoldo E. Bertossi, Jan Chomicki.
*Consistent Query Answers in Inconsistent Databases*. PODS 1999: 68-79 - 11. George Konstantinidis, José Luis Ambite.
*Scalable query rewriting: a graph-based approach*, SIGMOD '11 Proceedings of the 2011 international conference on Management of data. - 12. Hector Gonzalez, Alon Y. Halevy, Christian S. Jensen, Anno Langen, Jayant Madhavan, Rebecca Shapley, Warren Shen, Jonathan Goldberg-Kidon.
*Google fusion tables: web-centered data management and collaboration*. SIGMOD Conference 2010: 1061-1066 - 13. Mary Roth, Wang-Chiew Tan: Data Integration and Data Exchange: It's Really About Time. CIDR 2013
- 14. Bogdan Alexe, Balder ten Cate, Phokion G. Kolaitis, Wang Chiew Tan: Characterizing schema mappings via data examples. ACM Trans. Database Syst. 36(4): 23 (2011)
- 15. Anastasios Kementsietsidis, Marcelo Arenas, Renée J. Miller: Mapping Data in Peer-to-Peer Systems: Semantics and Algorithmic Issues. SIGMOD Conference 2003: 325-336

- 1. Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini, Moshe Y. Vardi.

In all the above three cases, once the student has chosen the topic, (s)he should send an email message to prof. Lenzerini with the description of the topic, and wait for confirmation, or a request to change the topic, if the topic (tool, paper, or use case) is already taken. Also once the student has decided on the date for the exam, (s)he should send an email message to prof. Lenzerini with the indication of the date. Here are the dates for March/April 2016 (the exam will be held in the office of Prof. Lenzerini), which is only for "fuori corso" students:

- April 5, 2016 at 4pm

**Schedule of exams**:- First exam: June 2015
- Second exam: July 2015
- Third exam: September 2015
- First special session: October 2015
- Fourth exam: January 2016
- Fifth exam: February 2016
- Second special session: April 2016

**Lectures**- When: during the period (March - May, 2015),
- Where: via Ariosto 25, Roma
- Schedule (lecture will be on Thursday, with the addition of Wednesday only in some of the weeks):

**Week****Wednesday (8:30am - 10:00am)**

classroom B2

**Thursday (8:30am -10:00am)**

classroom A2

**01 (Mar 2)**Lectures 1,2

- Introduction to information integration

- Propositional logic: syntax and semanticsLectures 3,4

- Propositional logics: algorithms for logical implication and satisfiability**02 (Mar 9)**Lectures 5,6

- First-order logic: syntax and semanticsLectures 7,8

- The relationship between First-order logic and databases**03 (Mar 16)**-------- Lectures 9,10

- Logic for expressing integrity constraints**04 (Mar 23)**-------- Lectures 11,12

- Types of information integration systems**05 (Mar 30)**Lectures 13,14

- Logical formalization of information integration systems-------- **06 (Apr 6)**-------- -------- **07 (Apr 13)**Lectures 15,16

- Types of mapping assertions: GAVLectures 17,18

- Types of mapping assertions: LAV**08 (Apr 20)**Lectures 19,20

- Algorithms for query answering in GAV without axioms-------- **09 (Apr 27)**Lectures 21,22

- Algorithms for data exchange in LAV without axioms-------- **10 (May 4)**-------- Lectures 23,24

- Algorithms for query answering in LAV without axioms**11 (May 11)**Lectures 25,26 (at 9am)

- Algorithms for query answering with axiomsLectures 27,28 (at 9am)

- Ontology-based data integration**12 (May 18)**

**Past editions**-
**Office hours.**Tuesday, 5:00 pm, at the Dipartimento di Informatica e Sistemistica "Antonio Ruberti",

via Ariosto 25, Roma, second floor, room B203 (if available), or room B217 (otherwise) -- please, look at the last

minute news for the next office hours