1. Database Management Systems Introduction

2. In the Beginning… Customer Program 1

3. Program-Data Dependence DATA DIVISION. FILE SECTION. FD EMP-FILE LABEL RECORDS ARE OMITTED. 01 EMP-RECORD. 05 EMP-NUMBERPIC 9(4). 05 EMP-LASTNAME PIC X(11). 05 EMP-FIRSTNAMEPIC X(11). 05 EMP-SEXPIC X(1). 05 EMP-DEPTIDPIC X(4). 05 EMP-SALARYPIC 9(8).

4. File System Model Cust Inv Sales Program 1 Program 2 Program 4 Program 3 Program 5

5. Problems with File System Model Changes to file structure or file location effect many programs causing high maintenance costs. Data in various and sometimes proprietary data formats. File Indexes were easily corrupted if not open during data entry, updates, or deletes. All Data validation was completely dependent on all application programs. All Data security was completely dependent on all application programs. Efficient Multi-application / multi-user access to the same file(s) required strict adherence to agreed upon locking strategies. Integrated backup and recovery of hundreds of data files is difficult to control. Tendency for redundant data to enter various data files.

6. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL Changes to file structure or file location are transparent to application programs. Maintenance costs drop dramatically.

7. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL All data is available through a standard SQL interface and related, industry standard query and reporting tools. Q & R tools

8. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 DBMS SQL All Indexes are automatically opened and updated during insert, update, and delete operations eliminating the primary cause of index corruption. Index Cust Index Sales Index Inv

9. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL All Data validation rules are defined within the DBMS and enforced independently of application program logic. Constraints

10. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL Primary responsibility for Data security is now handled by the DBMS providing user based security down to the attribute level. Users Grants

11. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL All aspects of multi-user access are handled by the DBMS. Locks Rollbacks Commits Transactions

12. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL A comprehensive, integrated solution to backup and recovery is provided. Backup Recovery Log Files Recovery

13. The Solution: DBMS File 1 File X Program 1 Program 2 Program 4 Program 3 Program 5 Cust Sales Inv DBMS SQL A single normalized conceptual model of all data managed by a database administrator (DBA) eliminating redundant and therefore inconsistent data. Schema DBA

14. Summary of DBMS Solutions Changes to file structure or file location are transparent to application programs. Maintenance costs drop dramatically. All data is available through a standard SQL interface and related, industry standard query and reporting tools. All Indexes are automatically opened and updated during insert, update, and delete operations eliminating the primary cause of index corruption. All Data validation rules are defined within the DBMS and enforced independently of application program logic. Primary responsibility for Data security is now handled by the DBMS providing user based security down to the attribute level. All aspects of multi-user access are handled by the DBMS. A comprehensive, integrated solution to backup and recovery is provided. A single conceptual model of all data managed by a DBA.

15. Relational Database Management Systems Key Constructs

16. Relations and Tuples EMPIDLNAMEFNAMEDEPTPHONESALARY 23JonesMarkITR555-108745000 25SmithSaraFINC555-222249000 26BillingsDavidACTG555-435642000 31DanceIvannaACTG444-488760000 32JonesMaryITR555-874570000 35BarkerBobACTG555-656544000 36WoodsRobinITR555-981290000 37JonesMaryFINC555-123456000 Employees Table SEX M F M F F M M F

17. Retrieving Info from Multiple Tables Programs Table EMPIDLANGUAGE 23 32 23 31 32 PROFICIENCY COBOLGOOD SQL JAVA GOOD EXCELLENT EMPIDLNAMEFNAMEDEPTPHONESALARY 23JonesMarkITR555-108745000 25SmithSaraFINC555-222255000 26BillingsDavidACTG555-435642000 31DanceIvannaACTG444-488760000 32JonesMaryITR555-874570000 35BarkerBobACTG555-656544000 36WoodsRobinITR555-981290000 37JonesMaryFINC555-123456000 Employees Table SEX M F M F F M M F 32 37 36 VBGOOD VB SQL COBOL JAVA COBOLEXCELLENT GOOD EXCELLENT NAME COBOL SQL JAVA VB FULLNAME COmmon Business Oriented Language Structured Query Language JAVA Visual Basic Languages Table 37SQLFAIR