1 Course overview grouped by System integration software types: 1.Homogeneous ERP systems integrated by using a common database. 2.Heterogeneous ERP systems from different suppliers may be integrated by using relaxed ACID properties. 3.Workflows and Relaxed transaction can send subtransactions to other systems and they may use a common (distributed) database. 4.Data warehouses integrate distributed data by sending data to a common data warehouse database by using ETL (Extract, Transform, and Load) of data from the operative systems.

2 Work flow example with insurance claims. What are the differences between Work flow diagrams and Flow chart diagrams?

3 Petri Net is an attempt to standardize Work Flows: Transition = Task. Token = Case with a transaction illustrated as a black dot in a place. Place = Queue for cases/transactions before a transition.

4 Terminology of WorkFlow Management Coalition Task = Atomic logic activity in a process. Case = Transaction in a process. Place = Queue for cases/transactions before a transition. Process = A set of tasks and a set of conditions that determine the order of the tasks.

Workflow for making mobile control of supplier deliveries. Delivery larger than ordered Delivery matches an Orderline Delivery less than ordered Delivery is not ordered Select a con- trol action Product deliveries Orderlines are replicated to the mobile controllers New Supplier orders. Orderlines Reduced product delivery AND JOIN Update the local stock Replicate the mobile registrations to the central ERP system Error reports Accepted product deliveries Accepted product deliveries End of workflow AND SPLIT Reduced orderline Input Input is supplier orders or deliveries. What is the most important part of the workflow from a system integration point of view?

Workflow for making mobile control of supplier deliveries. Delivery larger than ordered Delivery matches an Orderline Delivery less than ordered Delivery is not ordered Select a con- trol action Product deliveries Orderlines are replicated to the mobile controllers New Supplier orders. Orderlines Reduced product delivery AND JOIN Update the local stock Replicate the mobile registrations to the central ERP system Error reports Accepted product deliveries Accepted product deliveries End of workflow AND SPLIT Reduced orderline Input Input is supplier orders or deliveries. How would you implement the database of the workflow?

A:

Integrated E-commerce workflows: 1.Design the workflow between an e-commerce system and an ERP system that manage the stocks of products? 2. Is the possible to use the ERP system of the suppliers if a product is out of stock?

Example: Petri net Work flow for global E-commerce transactions where the stocks are in the locations of the different suppliers. OR split

Sub- Petri net of activity 2 When are the suborders committed globally in the location of the suppliers? AND split OR split AND join

Exercise The figure illustrates an ER-diagram of a car rental company like Hertz or Avis. Design a workflow for the car rental company including reservation, car pic up, car return, and car return service.

Exercise: Design a workflow for producing healthy patients. ER-diagram for a hospital.

Opgave 1.30 Beskriv databasen for et transportfirma og dets underleverandører med et integreret logistikstyringssystem, hvor pakker kan indsættes i collies, som herefter kan indsættes i containers, der kan transporteres af firmaet selv eller andre operatører/underleverandører. Transportruternes enkelte dele kaldes ”legs”. Det er vigtigt for transportfirmaet altid at vide, hvor en pakke er også selv om der er opstået fejl, hvor f. eks. en pakke, collie eller container er blevet beskadiget og derefter genpakket. Det er også vigtigt altid at kunne vælge den optimale transportmulighed, som kan afhænge af både transporttid og pris. Beskriv herefter et workflow for det integrerede transportsystem.

Hertil

Concept definitions used in logistics: Pallet = wooden skeleton where packages may be stored in such a way that they all can be moved by a truck. Collie = alle the packages that are stored on a pallet(palle). Leg = Route or subroute where the transportation does not have stops

ER-diagram of a logistics management system Transport Orders Customers Transport medias like ships, airplanes, and trucks. Physical containers Scheduled routes and legs Orderlines Packages, Collies and Containers Locations Route-leg hierarchy Package- Collie hierarchy Routes and legs from to Damage relationship from to Container-routes relationships of order 3 Transport operator Describe the local databases in the central location of the transport company, the locations of the integrated transport suppliers, and the mobile locations of the Transport medias. Design a workflow with focus on the integration of the local database locations.

17 The ACID properties are implemented by a DBMS (DataBase Management System). Relaxed ACID properties are implemented by the application programs. Atomicity Concistency Isolation Durability

18 Evaluation of distrubution architectures Evaluation criteria Distribution architectures Synchronous distributed database management system (DDBMS) Central database with distributed clients Multidatabases with flexible transactions. (Relaxed ACID properties) Hot backup possibility n-safe and mirroringOnly mirroring is possible 0- safe, 1 safe and mirroring Read performance/ capacity BestWorstAverage Write performanceWorstAverageBest Blocking possibilityYesNono Ease of failure recovery Worst (The systems are very complex) Best Disaster recoveryBestWorstAverage The probability of lost data[1][1] Best. p n Worst p Average Transaction loggingNot supported Recommended Availability[2][2]1-q n 1-q1-q n AtomicityBest ConsistencyBest Worst IsolationBest Worst DurabilityBest Develop-ment costsBest Worst [1][1] The probability of lost data as a function of the probability, say p, of a local disaster. [2][2] The availability as a function of the probability, say q, of a local site failure.

19 Evaluation of distribution architectures 1. Evaluation criteria Synchronous distributed database management system (DDBMS) Central database with distributed clients Multidatabases with flexible transactions. Hot backup possibility n-safe and mirroringOnly mirroring is possible 0- safe, 1 safe and mirroring Read per- formance/ capacity BestWorstAverage Write per- formance WorstAverageBest Blocking possibility YesNo Ease of failure recovery Worst (The systems are very complex) Best Ease of disaster recovery BestWorstAverage

20 Evaluation of distribution architectures 2. Evaluation criteria Synchronous distributed database management system (DDBMS) Central database with distributed clients Multidatabases with flexible transactions. The probability of lost data Best p n Worst pAverage Logging of the update transaction Not supported Recommended Availability1-q n 1-q1-q n AtomicityBest ConsistencyBest Worst IsolationBest Worst DurabilityBest Develop- ment costs Best Worst

End of session Thank you !!!

22 Database recovery: Exersice. A DB logfile stores before images and after images of all dataabase updates. The logfile also stores transaction starts and commitments. Periodically the checkpoint records are logged with the IDs of all non committed transactions. How is it possible to recover transaction types 1 to 5 after a transaction failure and a CPU failure respectively?

23 Two Phase Commit (2PC) and Two Phase Locking (2PL) Exercise. Describe the basic principles for the Two Phase Commit (2PC) recovery protocol and the Two Phase Locking (2PL) protocol for concurrency control.

24 Exercise: Describe exactly when a transaction is committed. What is the difference between failure and disaster recovery? Is the durability property always trustworthy? Is it possible to run batch programs that lock many thousends records concurrent with on line updates that only locks a few records?

25 ACID kravene til transaktionsafvikling: Atomicity = udelelighed. Concistency = konsistensen skal bevares Isolation = en transaktions opdateringer må ikke ses af andre før de er committede. Durability = Holdbarhed dvs. committede opdateringer skal kunne retableres

26 Full ACID løsninger.Relaxed ACID løsning.