Introduction to the new mainframe Chapter 12 Understanding































- Slides: 31

Introduction to the new mainframe Chapter 12 Understanding database managers on z/OS © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Chapter 12 objectives Be able to: Explain the role of DB 2 in online transaction processing. List common DB 2 data structures. Compose simple SQL queries to run on z/OS. Give an overview of application programming with DB 2. What the IMS components are The structure of the IMS DB subsystem © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Key terms in this chapter bind DBMS EXPLAIN modified source SPUFI SQL SYSADM view © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe DB 2 Concepts: Data Structures © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Schema structures User-defined Data Type (UDT) User-defined Function (UDF) Triggers Large Object (LOB) Stored Procedure © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe System Structure Catalog & Directory: stores ALL DB 2 information Buffer Pool Active and Archive Logs Bootstrap data set (BSDS) © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe DB 2 for z/OS Architecture DB 2 Address Spaces • System Service address space (SSAS) • Database Service address space (DBAS) • Internal Resource Lock Manager (IRLM) DB 2 Attachment Facilities • CICS • IMS • TSO © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL onneed z/OS: to. SPUFI First you create the output file (if not existing) Select option 1 to enter SPUFI © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL on z/OS: SPUFI (CONT…) Enter the input and output dataset, if they are not yet in place. Change the member of the PDS, if you want to enter a new SQL Defaults are set to NO from YES. © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL on z/OS: SPUFI (CONT…) Enter the SQL statement you want to execute. Press F 3 to return to the previous screen (to execute the SQL). © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL on z/OS: SPUFI (CONT…) When you get back to this screen, the “edit input” is put to “*”. Press ENTER to execute the SQL and to see the output. © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL on z/OS: SPUFI (CONT…) F 8 brings the rest of the results on your screen © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Invoke SQL on z/OS: SPUFI (CONT…) © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Application Programming: the flow © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Get the access path: EXPLAIN ALLEXPLAIN SET QUERYNO =1 SELECT EMPNO, LASTNAME FROM EMP WHERE LASTNAME = 'MILLER'; -The query is NOT executed -The access path is placed in userid. PLAN_TABLE, if it exists © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Other development options ODBC JAVA SQLJ JDBC XML Column Access XML Collection Access © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Managing DB 2: System Administration Installation System Object Management System and Disaster Recovery Monitoring System Performance © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Managing DB 2: Database Administration Creation & Management of DB 2 Objects Execution of Utilities: • Data Organization • Backup & recovery • Data Consistency Commands © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Functions of the IMS database manager A DBMS provides: • • Multiple-user access to a single copy of data Integrity for all updates Minimal hardware and OS access method dependencies Reduced data redundancy © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Implementation of IMS Databases Depending on user' requirements Technologies : • IMS DB or DL/I or DL 1 or Full Function Database • IMS DEDB or Data Entry DB or Fast Path Database • IMS Main storage database (MSDB) • IBM DB 2 Database Recovery Control (DBRC) © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Structure of IMS DB Subsystem © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Databases used by IMS: Database basics Access paths Normalization within IMS • Unique entities • 1 occurrence only • No many-to-many relationships © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Databases used by IMS: DB Model Sequence to access the segments © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Databases used by IMS: DB model Additional access paths to segments • Logical relationships • Secondary indices © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Application programming overview Program is subroutine of IMS region controller • Needs a program specification block (PSB) • Uses services: • • Send/receive message from terminals Access db Issue IMS commands Issue IMS service calls e. g. Checkpoint calls, Sync call © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Program Structure © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe IMS & the World Wide Web Message flow in IMS transaction © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe IMS & the World Wide Web Message flow between Web Browser & Web Server © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe flow IMS transaction & Web Server CGI Programs IMS Message & the World Wide Web © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Summary The relational database is the predominant approach to data organization in today's business world. IBM’s DB 2 implements such relational principles as primary keys, referential integrity, a language to access the database (SQL), nulls, and normalized design. In a relational database, the most fundamental structure is the table with columns and rows. © Copyright IBM Corp. , 2005. All rights reserved.

Introduction to the new mainframe Summary (continued) The only way to access the data in DB 2 databases is with SQL. On the mainframe, SPUFI is a tool used to enter SQL statements. The DBRM performs a bind process that determines the access path and stores this executable SQL code in a package. SQL can handle both static and dynamic statements, and EXPLAIN can be used to find out what access path the optimizer chose for the SQL. © Copyright IBM Corp. , 2005. All rights reserved.