Shashi K. Gadia
 

 

   Office: 203 Atanasoff
   Phone: (515) 451-4454
   Email: gadia@iastate.edu
   Department FAX: (515) 294-0258
 

   Vita: SKG-Vita.pdf

 

Research Interests

Non-atomic values in databases: XML where values are subtrees and parametric data where values are functions from parametric spaces consisting of points having one or more dimensions.
 
We have studied database models, query languages, incomplete information, query optimization in temporal, spatial and multilevel security databases. As ongoing efforts we have build prototypes for storage of large XML documents and geotemporal datasets in study of agriculture. We have also developed CyDIW (Cyclone Database Implementation Workbench), a workbench for using and implementing multiple databases from a central GUI. It can be used by undergraduate and graduate students, instructors, database prototype developers, and project managers. CyDIW provides various services such as page based storage if needed, benchmarking, and helps develop experiments that can be repeated in future.

Research Statement

In databases query languages are algebraic; for users queries are natural and easy to write and optimization is left to the system. Traditionally this framework is only available for atomic values. Our major interest is in extending this framework to non-atomic values. As non-atomic values can be complex in structure and arbitrarily large in size, one faces difficulties ranging from development of models and query languages to storage, implementation, and optimization. There are two major categories of non-atomic values: nested and semistructured values on one hand and parametric values that have underlying dimensions, such as space, time, and beliefs, on the other.

The nested and semistructured values of databases have been absorbed into the data model offered by XML and its associated query language XQuery. The reason of success of XML is that it is not tied to a linear arrangement of atomic values rather it offers a tree-based recursive model for information where values are sub-trees. XML is destined to become ubiquitous as it is found to be highly conducive to user data and metadata and various layers in a computer system ranging from hardware support, memory organization, secondary storage, to layers of software system architecture their specifications and interfacing. XML and efforts leading to it are not our creation; our participation is in enabling XML itself. There are multiple approaches to storage of XML; we too are developing easily deployable and efficient support for storage, access, and navigation of terabyte range XML documents. A full realization of this technology is a long-term exercise requiring efforts ranging from building support for XML-navigation in hardware, low level software-based navigation, and XQuery.

Parametric values are functions from one or multidimensional space of points. Although XML seems to absorb so many forms of data it is inherently non-conducive for modeling the behavior of parametric values to be linguistically satisfactory to users. We have given a methodology for natural unification of temporal, spatial, and belief dimensions. Our work, starting from scratch, involves a wide range of activities: development of models, query languages, dealing with incomplete information, pattern matching query optimization, access methods, implementation, and user interfaces. It is interesting to note that even though XML does not mimic linguistics of the concept of dimension, it can serve as a physical layer for parametric data that is extraordinarily easier to use for system building than any storage technology existing today. Our implementation of prototypes of parametric data is made possible due to the usage of our own XML-based storage technology at physical level.

Linguistically, XML and parametric values are mutually independent of each other; neither can absorb the other. Their understanding and deployment in computer systems will continue to grow for many decades to come. The linguistic advantages offered by our approach to parametric data are unsurpassed in temporal, spatial, and multilevel security database literatures.

Currently our focus is on the following projects.

1. Building technology to enable XML by providing support for it in hardware (CPU) and continue to use XML for system building.

2. A parametric database prototype for NC94 build in collaboration with our colleagues in meteorology and atmospheric sciences. NC94 is an important geotemporal dataset, consisting of climate, soil, and agricultural yield covering the north-central region of the United States during 1970 to 2000. The objective of this highly refined dataset developed by agriculturists, is to help build scientific models for study of agriculture and its relationship to natural phenomenon such as climate and spread of rust (crop-based soil diseases). The prototype will make NC94 more accessible to societal users ranging from farmers to policy makers.

3. A parametric model and query language for multilevel security database that would benefit privacy and confidentiality when information is shared in environments such as medical care and intelligence.

4. We have also developed a style for database implementation. All systems (subsystems) are developed in a modular fashion to support a command line interface. A common GUI is being implemented that allows commands from different subsystems to be executed in a single batch. The GUI has a language of its own that allows string variables to hold queries, the corresponding expression tree, display the expression tree in our native XML format or as a graph. Queries can be executed inside nested loops with different system parameters and performance benchmarks can be logged in XML-based log files created by the user. The benchmark results can be queried to generate reports (hopefully even graphs). Starting from empty disks, the entire exercise of creating a storage, buffer manager, loading real datasets or creating synthetic data, running queries, collecting and reporting benchmarks can be done by at the click of a button making experiments completely repeatable. Depending upon the experiment they can run from seconds to weeks and months unattended. The GUI helps make the system architecture at large self documenting. It is suitable for research and development as well as database implementation course (Com S 562 at ISU). In addition, the GUI can also run SQL and XQuery queries making it suitable for elementary database course (Com S 363 at ISU). It leads to a smooth interpolation between instruction and research.

  Education

Undergrad from Birla Institute of Technology and Science, Pilani.
Ph.D.   University of Illinois   1977
 

Publications

Sugam Sharma, U S Tim, S Gadia, and J Wong. Does SNAP Eligibility have Racial or Ethnic Gradients: A Geospatial Social Exploratory. International Journal of Information and Communication Technology, Inderscience, Vol 6, pp 189-212, 2014.

Sugam Sharma, Gadia S,and Tim U S. SubVizCon: Subsetting through Visualization and Conversion in GIS to Assist Complex Queries on Large Spatio-Temporal Datasets. (Under Review in Journal of Visual Languages & Computing (JVLC), Elsevier), 2014.

Sugam Sharma, U S Tim, M Payton, H Cohly, S Gadia, S Karakala. Association Rule Based Spatio-temporal Scheme to Regulate Exercise Patterns to Curb the Increasing Obesity in United States. To appear in Applied Computing and Informatics, Elsevier, 2014.

Sugam Sharma, Johnny Wong, U Sunday Tim, Shashi K Gadia. Bidirectional Migration between Variability and Commonality in Product Line Engineering of Smart Homes. International Journal of Systems Assurance Engineering and Management (IJSAEM), Springer, 2013.

Sugam Sharma, Gadia S,and Tim U S . Parametric Data Model Integration to Handle Temporal Databases in Geographic Information System. Geo-spatial Information Science. Taylor & Francis, 2013.

Xinyuan Zhao and Shashi K. Gadia. A Lightweight Workbench for Database Benchmarking, Experimentation, and Implementation. IEEE Transactions on Knowledge and Data Engineering. VOL. 24, 2012, pp 1937-1949.

Sugam S,Tim U S, and Gadia S. AutoConViz: Towards Automating the Conversion & Visualization in Geographic Information System. (Springer Journal) - Geo-spatial Information Science,2012

Sugam Sharma and Shashi K. Gadia. Perl Status Reporter (SRr) on Spatio-temporal Data Mining. International Journal of Computer science and engineering Survey (IJCSES), July 2010.

Sugam Sharma, Shashi K. Gadia, Niranjan Kumar, Valliappan Narayan, and Xinyuan Zhao, Climate Analysis in Iowa using XML and Spatiotemporal Dataset-NC94. International Journal of Database Management Systems(IJDMS), September, 2010. [Invited]

Seo-Young Noh, Shashi K. Gadia: Benchmarking temporal database models with interval-based and temporal element-based timestamping. Journal of Systems and Software 81(11): 1931-1943 (2008).

Seo-Young Noh, Shashi K. Gadia, Shihe Ma: An XML-based methodology for parametric temporal database model implementation. Journal of Systems and Software 81(6): 929-948 (2008)

Seo-Young Noh and Shashi K. Gadia. A Comparison of Two Approaches to Utilizing XML in Parametric Databases for Temporal Data. Information and Software Technology, 2006, Vol 48, pp807-819.

Cheng, Tsz-Shing and Shashi K. Gadia. The Event Matching Language for Temporal Data. IEEE Transactions on Data and Knowledge Engineering. Vol 14, pp 1119-1125, 2002.

Shashi K. Gadia and Sunil S. Nair. Algebraic identities and query optimization in a parametric model for relational temporal databases. To appear in IEEE Transactions on Knowledge and Data Engineering. Vol 10(5), pp 793-807, 1998.

L. L. Miller, J. Leszczylowski, S. K. Gadia and P. Chan. Storage model for processing semantic exceptions. International Journal of Computer Systems, Sciences and Engineering, Vol 9, 1994, pp 195-204.

Shashi K. Gadia. A Homogeneous Relational Model and Query Languages for Temporal Databases. ACM Transactions on Database Systems, Vol. 14, 1988, pp 418-448.

Shashi K. Gadia and Chuen-Sing Yeung. Inadequacy of interval time stamps in temporal databases. Information Sciences, Vol 54, 1991, pp 1-22.

Les Miller, Shashi K. Gadia, Ken Liu and Suraj Kothari. Completeness issues for join dependencies derived from the universal relation join dependency. Information Processing Letters, Vol 28, 1988, pp 269-274.

Gautam Bhargava and Shashi K. Gadia. Relational database systems with zero information-loss. IEEE Transactions on Knowledge and Data Engineering, Vol 5, pp 76-87, February 1993.

Xinyuan Zhao and Shashi K. Gadia. A Pagination-Based Index Structure on a Native XML Database. Third IEEE International Conference on Computer Research and Development (ICCRD 2011), 2011.

Sugam Sharma and Shashi K. Gadia. On Analyzing the Degree of Coldness in Iowa, a North Central Region, United States: An XML Exploitation in Spatial Database (NC94). First International Workshop on Database Management Systems (DMS 2010), Springer CCIS series, July 23-25, 2010.

Sugam Sharma, Shashi K. Gadia, and S. B. Goyal. On the Calculation of Coldness in Iowa, a North Central Region, United States: A Summary on XML Based Scheme in Spatial Database (NC94). International Conference on Advances in Information and Communication Technologies (ICT 2010), Springer CCIS series.

Sugam Sharma and Shashi K. Gadia. An XML-Based Range Variation Approach to Render the Coldness in Iowa, a North Central Region, United States. IEEE - Second International Conference on Information Management and Engineering (ICIME 2010), April 2010.

Sugam Sharma, P. Smith, U. Tim, and Shashi K. Gadia. Investigating the Eligibility of Population to Qualify for USDA’S SNAP in Iowa using GIS. Accepted, ACM International Conference on Advances in Computing and Communication (ACC 2011) July 2011.

Gadia, Shashi K, Navneet Goyal, William J Gutowski, Daryl Herzmann, Sree Nilakanta, and Anil Rai. Toward Next Generation Data Warehousing Technology and its Deployment in Agriculture. International Conference on 21st Century Challenges on Sustainable Agri-Food Systems, 2007, pp 487-496.

Seo-Young Noh and Shashi K. Gadia. User-Friendly Extendibility of Two Temporal Data Models to Spatiotemporal Data Models. First International Conference on Multimedia and Ubiquitous Engineering (MUE) 2007.

Seo-Young Noh and Shashi K. Gadia. An XML-based Framework for Temporal Database Implementation. Proc. Twelfth International Symposium on Temporal Representation and Reasoning (TIME-2005).

Noh, Seo-Young and Shashi K Gadia. Usability of XML in Parametric Databases for Temporal Data. International Conference on Information and Knowledge Engineering, pp 113-119. 2005.

Noh, Seo-Young and Shashi K Gadia. A Parametric Framework for Implementing Spatiotemporal Databases. 4th International Conference on Computer Science and its Applications, pp 312-319, 2004.

Seo-Young Noh, Shashi K. Gadia and Sangwoo Kim. An XML Plagiarism Detection Model for Procedural Programming Languages. The Second International Conference on Computer Science and Its Applications (ICCSA-2004).

Seo-Young Noh and Shashi K. Gadia. A Requirement Analysis Support Tool based on Linguistic Information. Hawaii International Conference on Computer Sciences, 2004.

Guerrini, Giovanna, Elisa Bertino, and Shashi K. Gadia. Dimension Alignment in Parametric Data. Proc. Eighth International Workshop on Temporal Representation and Reasoning, 2001.

Merlo, Isabella, Elisa Bertino, Elena Ferrari, Shashi K. Gadia, and Giovanna Guerrini. Querying Multiple Temporal Granularity Data. Proc. Seventh International Workshop on Temporal Representation and Reasoning, 2000.

Shashi K. Gadia, Applicability of Temporal Data Models to Query Multilevel Security Databases: A Case Study. Appeared in Temporal Databases: Research and Practice; Etzion, Jajodia, and Sripada, eds.; Lecture Notes in Computer Science, Vol 1399, pp238,256, Springer Verlag, Berlin, 1998.

Cheng, Tsz S. and Shashi K. Gadia. A pattern matching language for spatio-temporal databases. Proceedings of the Third International Conference on Information and Knowledge Management, pp 288-295, 1994.

Gadia, Shashi K. and Tsz S. Cheng. Some structural aspects of query languages in spatio-temporal databases. Workshop on Advances in Geographic Information Systems, Nov 1-5, 1993, Washington D.C.

Cheng, Tsz S., Shashi K. Gadia and Sunil S. Nair. Object identity and dimension alignment in parametric databases. Proceedings of the Second International Conference on Information and Knowledge Management, pp 615-624, 1993.

Cheng, Tsz S. and Shashi K. Gadia. An object oriented model for temporal databases. Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Edara, Madhuri L. and Shashi K. Gadia. Updates and incremental recomputation of active relational expressions in temporal databases. Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Gadia, Shashi K., Vimal Chopra and U. Sunday Tim. An SQL-like seamless query language for spatio-temporal data. Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Gadia, Shashi K. and Gautam Bhargava. SQL-like seamless query of temporal data. Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Gadia, Shashi K., Sunil S. Nair and Yiu-Cheong Poon. Incomplete information in relational temporal databases. Proceedings of the 18th International Conference on Very Large Databases, pp 395-406, 1992.

Also appeared in Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Nair, Sunil S. and Shashi K. Gadia. Algebraic optimization in a relational model for temporal databases. Proceedings of the first International conference on Information and Knowledge Management, pp 169-176, 1992.

Also appeared in Also appeared in Proceedings of the International Workshop on an infrastructure for temporal databases, June 14-16, 1993.

Gautam Bhargava and Shashi K. Gadia. The concept of an error in a database: an application of temporal databases. Appeared in Proceedings of INSDOC COMAD’90 International Conference on Management of Data, December 1990.

Sushil K. Jajodia, Shashi K. Gadia and Gautam Bhargava. Audit trail organization in Relational Databases. Proc. 3rd IFIP Working Group 11.3 Workshop on Database Security. Appeared as Database Security III, Status and Prospects, David Spooner and C.E. Landwehr, eds., North Holland, pp 269-281, 1990.

Gautam Bhargava and Shashi K. Gadia. Achieving zero -information-loss in a classical database environment. Proc. Fifteenth International Conference in Very Large Data Bases, 1989, pp 217-224.

Sushil K. Jajodia, Shashi K. Gadia, Gautam Bhargava and Edgar H. Sibley. Proc. of 2nd RADC Workshop on Database Security. Published as Research Directions in Database Security, II, T.F. Lunt, ed, SRI International 1989.

Shashi K. Gadia and Chuen-Sing Yeung. A generalized model for a relational temporal database. ACM SIGMOD Conference on Management of Data, 1988, pp 251-259.

Shashi K. Gadia. Weak Temporal Relations. Proc. Fifth Annual ACM SIGACT-SIGMOD Symp. on Principles of Database Systems, 1986. pp 70-77.

Shashi K. Gadia. Toward a Multihomogeneous Model for a Temporal Database. Proceedings of the IEEE International Conference on Data Engineering, 1986, pp 390-397.

Shashi K. Gadia and Jay H. Vaishnav. A Query Language for a Homogeneous Temporal Database. Proc. Fourth Annual ACM SIGACT-SIGMOD Symposium on Principles of Database Systems, 1985, pp 51-56.

(Refereed and invited.) Shashi K. Gadia, Applicability of Temporal Data Models to Query Multilevel Security Databases: A Case Study. To appear in Temporal Databases: Research and Practice; Etzion, Jajodia, and Sripada, eds.; Lecture Notes in Computer Science, Vol 1399, Springer Verlag, Berlin, 1998.

(Refereed and invited.) Gadia, Shashi K. and Vimal Chopra. A relational model and SQL-like query language for spatial databases. Advanced Database Systems; Eds. Nabil Adam and Bharat Bhargava, Lecture Notes in Computer Science, # 759, Springer Verlag, 1993, pp 213-225.

(Invited.) Shashi K. Gadia. The role of temporal elements in temporal databases. Data Engineering: quarterly bulletin of IEEE Computer Society, December 1988.

(Refereed and Invited) Gadia, Shashi K. and Sunil S. Nair. Temporal databases: a prelude to parametric data. In Temporal Databases: Theory, Design and Implementation. Editors: Tansel, A.U., James Clifford, Shashi K. Gadia, Sushil Jajodia, Arie Segev and Snodgrass. Benjamin/Cummings, Redwood City California, 1993.