An Investigation of Oracle and SQL Server with respect to Integrity, and SQL Language standards Presented by: Paul Tarwireyi Supervisor: John Ebden

Overview 1. Motivation 2. Problem Statement 8. Possible Extensions 5. Plan of action 3. SQL Language Standards 9. Questions 6. Deliverables / Expected results 7. Timeline 4. Integrity

Motivation Long standing debate between DBAs on Oracle and SQL Server Critical to choose the right DBMS from the start The criteria to be met to fulfil the needs of the organisation should be clarified There are many criteria and benchmarks to aid the choice of a DBMS For example platform support, ease of use, recoverability etc

Problem Statement In this project I will carry out a comparative investigation and evaluation of Oracle 9i - ( ) and Ms SQL Server ( ) With respect to Integrity and SQL Language standards (SQL: 2003) Both installed on Windows Server 2003

SQL Language Standards Specify the syntax and semantics of SQL language facilities for defining and accessing SQL databases. e.g. Schema definition Data manipulation Transaction management These standards were setup to protect customers from vendors making overly aggressive marketing strategies

SQL Language Standards (cont) There is an international committee working on the SQL standards (ISO/IEC JTC 1/SC 32/WG 3) as well as an American committee (ANSI TC NCITS H2) SQL-92 SQL: 1999 the previous standard: Core features Non-core features. SQL: 2003the current standard

Conformance to Standards Oracle, IBM and Microsoft make formal and clever statements about their conformance to the standards. For example: "The Core SQL: 1999 features that Oracle fully supports are listed in Table B-1..." -- Oracle Corporation, Oracle9i SQL Reference

Conformance (cont) "The Microsoft SQL Server 2000 Transact-SQL version complies with the Entry level of the SQL-92 standard..." -- Microsoft Corporation, SQL Server 2000 Books Online (Updated)

Conformance testing models The “Underwriters Laboratory (UL)” model – vendors pay independent organisation  Liability insurance companies demand it,  Consumers buy only tested products,  Wholesalers will buy only tested products. But that is no longer happening

Conformance testing models (cont) The “Consumers Union (CU)” model- individual organisation is funded by consumers They will in turn use these results to make informed buying decisions.

Integrity The quality, accuracy, consistency or completeness of the data stored in a database. In terms of GIGO integrity is all about keeping the Garbage out of the system There are four main types of data integrity:

Integrity (cont) Entity integrity Domain integrity Referential Integrity Synchronises relationships between tables  UPDATE threat: changing PK or FK  INSERT threat: inserting in child table (dangling tuples)  DELETE threat: deleting from parent table User Defined integrity Specific business rules

Implementing data Integrity Declarative data integrity Enforces integrity through constraints (data types) Limitations on columns e.g. PK, FK, NOT NULL etc Procedural data integrity Enforces integrity through Triggers Stored procedures.

Plan of action Carry out a literature search: mainly to obtain background knowledge and understanding of databases. Get to know SQL Server Creating and manipulating databases Get to know Oracle Creating and manipulating databases

Plan of action (cont) Carry out experiments to test Integrity Using scripts DML INSERT, UPDATE, DELETE, and SELECT DDL CREATE, ALTER, and DROP DCL GRANT and REVOKE Transaction Control ROLLBACK and COMMIT Investigate the language structures for conformity with SQL:2003 Are the commands written according to specifications.

Expected Results To produce a report detailing weaknesses and strengths in SQL Server and Oracle database systems, making recommendations about the optimal use of these products for different types of users.

Timeline Reading Literature and tutorialsFirst term Knowing Oracle and Ms SQL ServerFirst and second term Investigating them for integrity problems Second and third term Literature SurveyEnd of second term Investigating them for conformity to SQL:2003 Third term Prepare project PosterEnd of third term What (if anything) can be done to fix the problems Fourth term Final write upFourth term

Possible extensions Developing software which will test DBMSs for integrity. Evaluating the recoverability, backup, maintainability, security and so on. Evaluating the latest versions: SQL Server 2005 (Yukon) and Oracle 10g Performing similar tests with open source databases

Questions