Post on 02-Jan-2016
Chapter 15Relational Implementation
with DB2
David M. Kroenke
Database Processing
© 2000 Prentice Hall
Chapter 15
© 2000 Prentice Hall
DB2
“Database2; DBMS product licensed by IBM intended primarily for large IBM mainframes”
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© 2000 Prentice Hall
Key Features of DB2
• Implements a relational DBMS• Runs on IBM’s MVS operating system• Uses SQL to perform operations• Well suited to a multi-user environment• Robust recovery systems
• Uses DB2 Data Definition Language
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DB2 Data Definition Language
• TABLE stores data• VIEW virtual table• TABLE SPACE a collection of one or
more VSAM data sets (standard nondatabase IBM mainframe files)
• INDEX overhead data used to speed sorting and retrieving data
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DB2 Data Definition Language
• INDEX SPACES area of disk storage where DB2 stores an index
• DATA BASES a collection of DB2 tables and indexes and the storage areas that hold them
• STORAGE GROUPS a group of disk volumes on which DB2 allocates space for user data bases
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Using DB2
• Create Tables, Views, and Indexes• Delete Tables and Views• Use DB2 SQL to Manipulate Data• Use SQL Statements in the
Procedure Division
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DB2 Concurrent Processing
“implemented through shared locks (allow other applications to read the data) and exclusive locks (prevent all other applications from accessing the data)”
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© 2000 Prentice Hall
DB2 Concurrent Processing Issues
• COMMIT and ROLLBACK• DEADLOCK
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DB2 Backup and Recovery Issues
• Before-images• After-images• Backing up only pages in a table
space that have been modified since the latest backup
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DB2 Security Issues
• Views• Limiting Access to DB2 Resources• Identifying Users
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