What’s in the Box DBMS Features

Access Specific S13 MIS 2 “Form” screen construction to support “stand alone” applications Report Contents are Tables and Query results Support for manipulating Report Format Recall you’ve seen a similar feature as a “plug in” to MapInfo called Crystal Reports

Goal of Enterprise Databases S13 MIS 3 Single instance of the data – minimize redundancy & maximizes data coherence Many simultaneous users – consistent data transaction processing system (TPS) Data recovery tools – Backup and Rollback Large scale storage Millions of records Strong backup / recover / rollback tools Very Flexible Fast query without having to pick “most important” data fields

Database Activities S13 MIS 4 Data Description Designing and Relating Tables MetaData Building Queries (custom records) Query Language / Engine Insuring Data Integrity TPS, Authentication, Backup/Rollback Make DB available Views APIs

Managing Transactions S13 MIS 5 A Transaction is any change to the DBMS that must be indivisible Credit Check, order creation Ticket purchase, ticket allocation Transaction Processing System (TPS) Atomic Transactions – indivisible No matter how many transactions are being done.

Transaction Processing TPS S13 MIS 6 Data Consistency under “simultaneous” activity Inventory - Widgets, On hand: 10 No TPS - Event sequence (on line activity) 1. Joe looks at widgets record, sees Jan looks at widgets record, sees Joe orders 8 widgets, 10 => 2 on hand 4. Jan orders 5 widgets, 10=> 5 on hand Trouble filling the orders AND Inventory on hand is wrong!!!

TPS – Atomic Events S13 MIS 7 Micro TPS Event Sequence (on line activity) John wants 5 widgets, so his client app 0. Request access to Widget record (may have to wait) 1. Locks Widget Record (all other requests are queued) 2. Journals (to file) : Trans #, PREVIEW, Widgets, Changes Widget Record: Widgets 10=>5 4. Journals (to file) : Trans #, POSTVIEW, Widgets 5 5. Unlocks Widget Record Next waiting request gets to lock record

Query Engine S13 MIS 8 Support asking Queries Write and Edit queries Check that queries are correct (syntax check) Execute Query Support using results

FTC – Table Structure

What Tables are Needed? S13 MIS 10 Left Side – CS/Ops Client Info, Facilities Info Right Side – Accounting Client Accounts Departmental Budgets

Relate Tables S13 MIS 11 Draw essential Relationships Indicate where Foreign Keys will be needed