* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Slides from Lecture 6 - Courses - University of California, Berkeley
Survey
Document related concepts
Transcript
Database Design: Normalization and Access DB Creation University of California, Berkeley School of Information Management and Systems SIMS 257: Database Management IS 257 – Spring 2004 2004.02.05 - SLIDE 1 Lecture Outline • Review – Database Design -- Object-Oriented Modeling • Logical Design for the Diveshop database • Normalization • Access Database Creation IS 257 – Spring 2004 2004.02.05 - SLIDE 2 Lecture Outline • Review – Database Design -- Object-Oriented Modeling • Logical Design for the Diveshop database • Normalization • Access Database Creation IS 257 – Spring 2004 2004.02.05 - SLIDE 3 Database Design Process Application 1 External Model Application 2 Application 3 Application 4 External Model External Model External Model Application 1 Conceptual requirements Application 2 Conceptual requirements Application 3 Conceptual requirements Conceptual Model Logical Model Internal Model Application 4 Conceptual requirements IS 257 – Spring 2004 2004.02.05 - SLIDE 4 Object-Oriented Modeling • Becoming increasingly important as – Object-Oriented and Object-Relational DBMS continue to proliferate – Databases become more complex and have more complex relationships than are easily captured in ER or EER diagrams • (Most UML examples based on McFadden, “Modern Database Management”, 5th edition) IS 257 – Spring 2004 2004.02.05 - SLIDE 5 Class Diagrams • A class diagram is a diagram that shows a set of classes, interfaces, and/or collaborations and the relationships among these elements. IS 257 – Spring 2004 2004.02.05 - SLIDE 6 UML Class Diagram DIVEORDS Order No Customer No Sale Date Shipvia PaymentMethod CCNumber No of People Depart Date Return Date Destination Vacation Cost CalcTotalInvoice() CalcEquipment() IS 257 – Spring 2004 Class Name List of Attributes List of operations 2004.02.05 - SLIDE 7 Associations: Unary relationships * 0..1 Person 0..1 IS 257 – Spring 2004 Is-married-to manages Employee 0..1 manager 2004.02.05 - SLIDE 8 Associations: Binary Relationship Employee 0..1 Is-assigned Parking Place 0..1 One-to-one Product Line 1 contains * Product One-to-many Student * Registers-for * Course Many-to-many IS 257 – Spring 2004 2004.02.05 - SLIDE 9 Associations: Ternary Relationships Part * Vendor IS 257 – Spring 2004 * Supplies * Warehouse 2004.02.05 - SLIDE 10 Association Classes Registers-for Student * Course * Computer Account Registration _________________ ________________ acctID Term issues Password * 0..1 Grade ServerSpace ________________ CheckEligibility() IS 257 – Spring 2004 2004.02.05 - SLIDE 11 Derived Attributes, Associations, and Roles Course Student Course Offering _________ ____________ ____________ Scheduled-for name Registers-for crseCode term ssn * crseTitle * * 1 section dateOfBirth creditHrs time Derived /age location attribute * * /participant Derived role {age = currentDate – dateOfBirth} /Takes Derived association IS 257 – Spring 2004 2004.02.05 - SLIDE 12 Generalization Employee ____________ empName empNumber address dateHired ____________ printLabel() Hourly Employee _______________ HourlyRate _______________ computeWages() IS 257 – Spring 2004 Salaried Employee _______________ Annual Sal stockoption _______________ Contributepension() Consultant _______________ contractNumber billingRate _______________ computeFees() 2004.02.05 - SLIDE 13 Other Diagramming methods • SOM (Semantic Object Model) • Object Definition Language (ODL) – Not really diagramming • Access relationships display • Hybrids IS 257 – Spring 2004 2004.02.05 - SLIDE 14 Lecture Outline • Review – Database Design -- Object-Oriented Modeling • Logical Design for the Diveshop database • Normalization • Access Database Creation IS 257 – Spring 2004 2004.02.05 - SLIDE 15 Database Design Process Application 1 External Model Application 2 Application 3 Application 4 External Model External Model External Model Application 1 Conceptual requirements Application 2 Conceptual requirements Application 3 Conceptual requirements Conceptual Model Logical Model Internal Model Application 4 Conceptual requirements IS 257 – Spring 2004 2004.02.05 - SLIDE 16 DiveShop ER Diagram Customer No DiveCust 1 Destination Name Destination no Customer No ShipVia n Dest n 1 DiveOrds n 1 ShipVia ShipVia 1 Destination no Site No 1 n Site No BioSite Species No 1 Destination n Sites Order No n 1 1/n ShipWrck Order No DiveItem n Item No n Site No 1 Species No BioLife IS 257 – Spring 2004 1 DiveStok Item No 2004.02.05 - SLIDE 17 Logical Design: Mapping to a Relational Model • Each entity in the ER Diagram becomes a relation. • A properly normalized ER diagram will indicate where intersection relations for many-to-many mappings are needed. • Relationships are indicated by common columns (or domains) in tables that are related. • We will examine the tables for the Diveshop derived from the ER diagram IS 257 – Spring 2004 2004.02.05 - SLIDE 18 Customer = DIVECUST Customer No Name Street City State/Prov Zip/Postal Code Country 1480 Louis Jazdzewski 2501 O'Connor New Orleans LA 60332 U.S.A. 1481 Barbara Wright 6344 W. Freeway San Francisco CA 95031 U.S.A. 1909 Stephen Bredenburg 559 N.E. 167 Indianapolis Place IN 46241 U.S.A. 1913 Phillip Davoust 123 First Street Berkeley CA 94704 U.S.A. 1969 David Burgett 320 Montgomery SeattleStreet WA 98105 U.S.A. 2001 Mary Rioux1701 Gateway Pueblo Blvd. #385 CO 81002 U.S.A. 2306 Kim Lopez 14134 Nottingham HonoluluLane HI 96826 U.S.A. 2589 Hiram Marley 7233 Mill Run SanDrive Francisco CA 94123 U.S.A. 3154 Tanya Kulesa 505 S. Flower, NewMail YorkStop NY 48943 10032 U.S.A. 3333 Charles Sekaron 110 East Park Miller Avenue,SD Box 8 57362 U.S.A. 3684 Lowell Lutz915 E. Fesler Dallas TX 75043 U.S.A. 4158 Keith Lucas56 South Euclid Chicago IL 60542 U.S.A. 4175 Karen Ng 2134 ElmhillKlamath Pike Falls OR 97603 U.S.A. 5510 Ken Soule 58 Sansome Aurora Street CO 89022 U.S.A. IS 257 – Spring 2004 Phone First Contact (902) 555-88881/29/95 (415) 555-43212/2/93 (317) 555-36441/5/93 (415) 555-91843/9/98 (206) 555-75803/12/99 (719) 555-20103/15/97 (808) 555-50501/29/99 (415) 555-64302/18/99 (212) 555-67501/30/99 (613) 555-43333/16/98 (214) 555-27222/15/99 (312) 555-43103/17/98 (503) 555-47003/20/99 (303) 555-66952/5/99 2004.02.05 - SLIDE 19 Dive Order = DIVEORDS Order No Customer No Sale Date 307 1480 9/1/99 310 1481 9/1/99 313 1909 9/1/99 314 1913 9/1/99 317 1969 9/1/99 320 2001 9/1/99 321 2306 9/1/99 325 2589 9/1/99 326 3333 9/1/99 327 3684 9/1/99 329 4158 9/1/99 330 4175 9/1/99 331 5510 9/1/99 333 5926 9/1/99 336 5719 9/1/99 IS 257 – Spring 2004 Ship Via UPS FedEx Walk In FedEx FedEx Walk In Emery Emery FedEx DHL Walk In FedEx FedEx DHL FedEx PaymentMethod CcNumber CcExpDateNo Of People Depart DateReturn DateDestinationVacationCost Visa 12345 678 90 1/1/01 2 11/8/00 11/15/00 Fiji 10000 Check 1 4/4/00 4/18/00 Santa Barbara 6000 Visa 456456456 9/11/00 4 6/27/00 7/11/00 Cozumel 8000 Check 3 2/7/00 2/14/00 Monterey 6000 AmEx 432432432 12/31/02 4 5/9/00 5/16/00 Fiji 20000 Cash 1 10/10/00 10/17/00 Santa Barbara 3000 Master Card 1112223334 8/12/00 1 3/15/00 4/12/00 New Jersey 8000 AmEx 332332332 12/10/99 1 3/15/00 4/12/00 New Jersey 8000 Money Order 2 2/10/00 2/17/00 Monterey 4000 Master Card 122122321 11/9/99 4 3/10/00 3/23/00 Florida 24000 Cash 1 5/4/00 5/15/00 Cozumel 1571 Check 2 7/3/00 7/10/00 Florida 6000 Money Order 6 6/20/00 6/30/00 Santa Barbara 36000 Discover 123123123 12/21/00 2 6/10/00 6/17/00 Fiji 10000 Cash 10 4/2/00 4/24/00 Great Barrier Reef 200000 2004.02.05 - SLIDE 20 Line item = DIVEITEM Order No Item No 307 90010 307 90020 307 90021 307 90030 307 90051 310 90011 310 90045 310 90059 310 90074 310 90078 313 90127 314 90072 314 90094 314 90100 317 90012 IS 257 – Spring 2004 Rental/SaleQty Rental Rental Rental Rental Rental Rental Rental Rental Rental Rental Sale Rental Rental Rental Sale Line Note 4 1 1 2 2 1 1 1 1 1 1 3 3 3 2 This is our most popular mask. These are our best selling fins. A good weight belt for beginners Holds 10 cubic feet of cargo. 2004.02.05 - SLIDE 21 Shipping information = SHIPVIA Ship Via DHL Emery FedEx UPS US Mail IS 257 – Spring 2004 Ship Cost 8 11 12 10 6 2004.02.05 - SLIDE 22 Dive Equipment Stock= DIVESTOK Item No 90010 90011 90012 90020 90021 90022 90023 90024 90025 90030 90031 90032 90033 90040 90041 90042 DescriptionEquipment On Class Hand Reorder Point Cost Sale Price Rental Price Shotgun 2 Snorkel - Clear 12 2 $18.00 $30.00 $2.00 Shotgun 2 Snorkel - Red 12 2 $18.00 $30.00 $2.00 Shotgun 2 Snorkel - Teal 11 2 $18.00 $30.00 $2.00 Tri-Vent Mask Mask - Clear 14 2 $62.50 $100.00 $5.00 Tri-Vent Mask Mask - Red 10 2 $62.50 $100.00 $5.00 Tri-Vent Mask Mask - Teal 14 2 $62.50 $100.00 $7.00 Quad Vision Mask Mask - Clear 11 2 $48.25 $80.00 $7.00 Quad Vision Mask Mask - Red 13 2 $48.25 $80.00 $7.00 Quad Vision Mask Mask - Teal 10 2 $48.25 $80.00 $10.00 Sea Wing Fins Fins - Clear 12 2 $60.00 $100.00 $12.00 Sea Wing Fins Fins - Red 11 2 $60.00 $100.00 $12.00 Sea Wing Fins Fins - Teal 12 2 $60.00 $100.00 $12.00 Jet Fin - Black Fins 14 2 $30.00 $60.00 $10.00 D350 Second Regulator Stage 11 1 $162.50 $270.00 $20.00 G250 Second Regulator Stage 13 1 $144.50 $240.00 $20.00 G200 Second Regulator Stage 12 1 $105.25 $175.00 $20.00 IS 257 – Spring 2004 2004.02.05 - SLIDE 23 Dive Locations = DEST DestinationDestination No Avg Name Temp Avg (F) Temp Spring (C) Temp Spring (F) Temp Summer (C) Temp Summer (F) Temp Fall Temp (C) (F) Fall Temp (C) Winter Temp Winter (F) Temp Accomodations (C) Night Life 1 Cozumel 78 25.556 76 24.444 84 28.889 78 25.556 74 23.333 Cheap Sleepy 2 Great Barrier Reef80 26.667 76 24.444 84 28.889 78 25.556 76 24.444 Moderate Pleasant 3 Monterey 60 15.556 62 16.667 64 17.778 64 17.778 58 14.444 Expensive Wild 4 Santa Barbara 75 23.889 73 22.777 78 25.556 72 22.222 70 21.111 Expensive Wild 5 Florida 77 25 75 23.889 85 29.444 78 25.556 70 21.111 Moderate Pleasant 6 Fiji 75 23.889 76 24.444 80 26.667 74 23.333 70 21.111 Expensive Sleepy 7 New Jersey 57 13.889 57 13.89 60 15.556 58 14.444 53 11.667 Expensive Pleasant IS 257 – Spring 2004 Body of Water Travel Cost Caribbean 1000 Coral Sea 5000 Pacific 2000 Pacific 3000 Caribbean 3000 South Pacific 5000 Atlantic 2000 2004.02.05 - SLIDE 24 Dive Sites = SITE Site No DestinationSite No Name Site HighlightSiteDistance NotesDistance from Depth Town from(m) (ft)Depth Town (km) (m) Visibility (ft)Visibility (m) Current 1001 1 Palancar Reef Reef 10 16.09 100 30.48 150 45.72 Strong 1002 1 Santa Rosa ReefReef 8 12.87 80 24.384 150 45.72 Strong 1003 1 Chancanab ReefR eef 4 6.437 60 18.288 100 30.48 Mild 1004 1 Punta Sur Reef 13 20.92 120 36.576 175 53.34 Strong 1005 1 Yocab Reef Reef 6 9.656 50 15.24 100 30.48 Mild 2001 2 Heron Island Reef 50 80.47 90 27.432 150 45.72 Mild 2002 2 Cod Hole Fish 45 72.42 50 15.24 150 45.72 Mild 2003 2 Butterfly Bay Caves 20 32.19 70 21.336 70 21.336 None 2004 2 Wheeler Reef Marine Life 30 48.28 50 15.24 125 38.1 Mild 2005 2 Watanabe Marine Life 130 209.2 150 45.72 200 60.96 None 3001 3 Point Lobos Marine Life 3 4.828 60 18.288 75 22.86 None 3002 3 Macabee BeachMarine Life 0.1 0.161 40 12.192 40 12.192 None 3003 3 Pinnacles Pinnacle 1 1.609 60 18.288 50 15.24 Mild 3004 3 Monastery Beach Marine Life 3 4.828 50 15.24 40 12.192 Surge IS 257 – Spring 2004 Skill Level Intermediate Intermediate Beginning Advanced Beginning Intermediate Beginning Advanced Beginning Intermediate Beginning Beginning Beginning Beginning 2004.02.05 - SLIDE 25 Sea Life = BIOLIFE Species NoCategory Common Name Species Name Length (cm) Length (in) Notes Graphic 90020 TriggerfishClown TriggerfishBallistoides conspicillum 50 19.685 90030 Snapper Red Emperor Lutjanus sebae 60 23.622 90050 Wrasse Giant Maori Wrasse Cheilinus undulatus 229 90.157 90070 Angelfish Blue Angelfish Pomacanthus nauarchus 30 11.811 90080 Cod Lunartail RockcodVariola louti 80 31.496 90090 Scorpionfish Firefish Pterois volitans 38 14.961 90100 ButterflyfishOrnate Butterflyfish Chaetodon Ornatissimus 19 7.4803 90110 Shark Swell Shark Cephaloscyllium ventriosum 102 40.157 90120 Ray Bat Ray Myliobatis californica 56 22.047 90130 Eel California Moray Gymnothorax mordax 150 59.055 90140 Cod Lingcod Ophiodon elongatus 150 59.055 IS 257 – Spring 2004 2004.02.05 - SLIDE 26 BIOSITE -- linking relation Species No Site No 90010 2001 90010 2002 90010 2003 90010 2004 90010 2005 90010 6001 90010 6003 90010 6004 90010 6005 90020 2001 90020 2002 IS 257 – Spring 2004 2004.02.05 - SLIDE 27 Shipwrecks = SHIPWRK Ship Name Site No Delaware 7007 F.S.Loop 4004 Gosford 4001 Great Isaac 7002 Lizzie D 7001 Mohawk 7004 R.P. Resor 7006 Star of Scotland 4002 Tolten 7008 USS Moody 4006 Valiant 4003 Category Type Interest TonnageLength (ft) Length (m) Beam (ft) Beam (m) Commercial Steam Freighter Treasure 1646 252 76.8096 37 11.2776 Commercial Steam Schooner Machinery 794 193 58.8264 39 11.8872 Commercial Barque Rigged Fixture Sail 2250 280 85.344 42 12.8016 Commercial Seagoing Tug Fixture 1117 185 56.388 37 11.2776 Commercial Tug/Rumrunner Treasure 122 84 25.6032 21 6.4008 PassengerOcean Liner Treasure 8140 402 122.5296 54 16.4592 Commercial Oil Tanker Treasure 7450 435 132.588 66.8 20.36064 PassengerBritish Q-Boat Treasure 1250 263 80.1624 35 10.668 Commercial Freighter Fixture 1858 280 85.344 43 13.1064 Military WWI Destroyer Treasure 1308 314 95.7072 31 9.4488 PassengerLuxury Motor Treasure Yacht 444 162.4 49.49952 26 7.9248 IS 257 – Spring 2004 Cause Date Sunk Comments Passengers/Crew Survivors Condition Graph Fire 66 66 Broken Deliberate 1/1/47 0 Scattered Fire Intact Collision 4/16/47 27 27 Intact Unknown 10/19/22 8 0 Intact Collision 1/25/35 163 118 Scattered Military 2/28/42 50 2 Broken Weather 1/22/42 5 4 Broken Military 3/13/42 28 1 Intact Deliberate 1/1/33 0 Intact Fire 12/17/30 25 25 Intact 2004.02.05 - SLIDE 28 Mapping to Other Models • Hierarchical – Need to make decisions about access paths • Network – Need to pre-specify all of the links and sets • Object-Oriented – What are the objects, datatypes, their methods and the access points for them • Object-Relational – Same as relational, but what new datatypes might be needed or useful (more on OR later) IS 257 – Spring 2004 2004.02.05 - SLIDE 29 Lecture Outline • Review – Database Design cont. Object-Oriented Modeling • Logical Design for the Diveshop database • Normalization • Access Database Creation IS 257 – Spring 2004 2004.02.05 - SLIDE 30 Normalization • Normalization theory is based on the observation that relations with certain properties are more effective in inserting, updating and deleting data than other sets of relations containing the same data • Normalization is a multi-step process beginning with an “unnormalized” relation – Hospital example from Atre, S. Data Base: Structured Techniques for Design, Performance, and Management. IS 257 – Spring 2004 2004.02.05 - SLIDE 31 Normal Forms • • • • • • First Normal Form (1NF) Second Normal Form (2NF) Third Normal Form (3NF) Boyce-Codd Normal Form (BCNF) Fourth Normal Form (4NF) Fifth Normal Form (5NF) IS 257 – Spring 2004 2004.02.05 - SLIDE 32 Normalization No transitive dependency between nonkey attributes All determinants are candidate keys - Single multivalued dependency IS 257 – Spring 2004 BoyceCodd and Higher Functional dependency of nonkey attributes on the primary key - Atomic values only Full Functional dependency of nonkey attributes on the primary key 2004.02.05 - SLIDE 33 Unnormalized Relations • First step in normalization is to convert the data into a two-dimensional table • In unnormalized relations data can repeat within a column IS 257 – Spring 2004 2004.02.05 - SLIDE 34 Unnormalized Relation Patient # Surgeon # 145 1111 311 Surg. date Patient Name Jan 1, 1995; June 12, 1995 John White Patient Addr Surgeon 15 New St. New York, NY 243 1234 467 2345 189 Jan 8, 1996 Charles Brown 4876 145 Nov 5, 1995 Hal Kane 5123 145 May 10, 1995 Paul Kosher Charles Field 10 Main St. Patricia Rye, NY Gold Dogwood Lane Harrison, David NY Rosen 55 Boston Post Road, Chester, CN Beth Little Blind Brook Mamaronec k, NY Beth Little 6845 243 Apr 5, 1994 Dec 15, 1984 Ann Hood Hilton Road Larchmont, Charles NY Field IS 257 – Spring 2004 Postop drug Drug side effects Gallstone s removal; Beth Little Kidney Michael stones Penicillin, Diamond removal none- Apr 5, 1994 May 10, 1995 Mary Jones Surgery rash none Eye Cataract removal Thrombos Tetracyclin Fever is removal e none none Open Heart Surgery Cholecyst ectomy Gallstone s Removal Eye Cornea Replacem ent Eye cataract removal Cephalosp orin none Demicillin none none none Tetracyclin e Fever 2004.02.05 - SLIDE 35 First Normal Form • To move to First Normal Form a relation must contain only atomic values at each row and column. – No repeating groups – A column or set of columns is called a Candidate Key when its values can uniquely identify the row in the relation. IS 257 – Spring 2004 2004.02.05 - SLIDE 36 First Normal Form Patient # Surgeon # Surgery DatePatient Name Patient Addr Surgeon Name 1111 145 01-Jan-95 John White 1111 311 12-Jun-95 John White 15 New St. New York, NY 15 New St. New York, NY 1234 243 05-Apr-94 Mary Jones 10 Main St. Rye, NY 1234 467 10-May-95 Mary Jones 2345 4876 5123 6845 6845 189 145 145 243 243 IS 257 – Spring 2004 Charles 08-Jan-96 Brown 10 Main St. Rye, NY Dogwood Lane Harrison, NY 05-Nov-95 Hal Kane 55 Boston Post Road, Chester, CN 05-Apr-94 Ann Hood 15-Dec-84 Ann Hood Hilton Road Larchmont, NY Drug adminSide Effects Charles Field Gallstone s removal Kidney stones removal Eye Cataract removal Patricia Gold Thrombos is removal none none David Rosen Open Heart Surgery none Beth Little Cholecyst ectomy Demicillin Beth Little Michael Diamond Blind Brook Mamaronec 10-May-95 Paul Kosher k, NY Beth Little Hilton Road Larchmont, NY Surgery Penicillin rash none none Tetracyclin e Fever Cephalosp orin Charles Field Gallstone s Removal none Eye Cornea Replacem Tetracyclin ent e Charles Field Eye cataract removal none none none Fever none 2004.02.05 - SLIDE 37 1NF Storage Anomalies • Insertion: A new patient has not yet undergone surgery -- hence no surgeon # -- Since surgeon # is part of the key we can’t insert. • Insertion: If a surgeon is newly hired and hasn’t operated yet -- there will be no way to include that person in the database. • Update: If a patient comes in for a new procedure, and has moved, we need to change multiple address entries. • Deletion (type 1): Deleting a patient record may also delete all info about a surgeon. • Deletion (type 2): When there are functional dependencies (like side effects and drug) changing one item eliminates other information. IS 257 – Spring 2004 2004.02.05 - SLIDE 38 Second Normal Form • A relation is said to be in Second Normal Form when every nonkey attribute is fully functionally dependent on the primary key. – That is, every nonkey attribute needs the full primary key for unique identification IS 257 – Spring 2004 2004.02.05 - SLIDE 39 Second Normal Form Patient # 1111 1234 2345 4876 5123 6845 IS 257 – Spring 2004 Patient Name Patient Address 15 New St. New John White York, NY 10 Main St. Rye, Mary Jones NY Charles Dogwood Lane Brown Harrison, NY 55 Boston Post Hal Kane Road, Chester, Blind Brook Paul Kosher Mamaroneck, NY Hilton Road Ann Hood Larchmont, NY 2004.02.05 - SLIDE 40 Second Normal Form Surgeon # Surgeon Name 145 Beth Little 189 David Rosen 243 Charles Field 311 Michael Diamond 467 Patricia Gold IS 257 – Spring 2004 2004.02.05 - SLIDE 41 Second Normal Form Patient # Surgeon # Surgery Date 1111 1111 1234 1234 2345 4876 Drug Admin Side Effects 145 Gallstones 01-Jan-95 removal Kidney Penicillin rash 311 stones 12-Jun-95 removal none none 243 Eye Cataract 05-Apr-94 removal Tetracycline Fever 467 Thrombosis 10-May-95 removal 189 Open Heart 08-Jan-96 Surgery Cephalospori n none 145 Cholecystect 05-Nov-95 omy Demicillin none none none none none 5123 145 6845 243 6845 243 IS 257 – Spring 2004 Surgery Gallstones 10-May-95 Removal Eye cataract 15-Dec-84 removal Eye Cornea 05-Apr-94 Replacement none none Tetracycline Fever 2004.02.05 - SLIDE 42 1NF Storage Anomalies Removed • Insertion: Can now enter new patients without surgery. • Insertion: Can now enter Surgeons who haven’t operated. • Deletion (type 1): If Charles Brown dies the corresponding tuples from Patient and Surgery tables can be deleted without losing information on David Rosen. • Update: If John White comes in for third time, and has moved, we only need to change the Patient table IS 257 – Spring 2004 2004.02.05 - SLIDE 43 2NF Storage Anomalies • Insertion: Cannot enter the fact that a particular drug has a particular side effect unless it is given to a patient. • Deletion: If John White receives some other drug because of the penicillin rash, and a new drug and side effect are entered, we lose the information that penicillin can cause a rash • Update: If drug side effects change (a new formula) we have to update multiple occurrences of side effects. IS 257 – Spring 2004 2004.02.05 - SLIDE 44 Third Normal Form • A relation is said to be in Third Normal Form if there is no transitive functional dependency between nonkey attributes – When one nonkey attribute can be determined with one or more nonkey attributes there is said to be a transitive functional dependency. • The side effect column in the Surgery table is determined by the drug administered – Side effect is transitively functionally dependent on drug so Surgery is not 3NF IS 257 – Spring 2004 2004.02.05 - SLIDE 45 Third Normal Form Patient # Surgeon # Surgery Date Surgery Drug Admin 1111 145 1111 311 01-Jan-95 Gallstones removal Kidney stones 12-Jun-95 removal 1234 243 05-Apr-94 Eye Cataract removal Tetracycline 1234 467 10-May-95 Thrombosis removal 2345 189 08-Jan-96 Open Heart Surgery Cephalosporin 4876 145 05-Nov-95 Cholecystectomy Demicillin 5123 145 10-May-95 Gallstones Removal none 6845 243 none 6845 243 15-Dec-84 Eye cataract removal Eye Cornea 05-Apr-94 Replacement IS 257 – Spring 2004 Penicillin none none Tetracycline 2004.02.05 - SLIDE 46 Third Normal Form Drug Admin IS 257 – Spring 2004 Side Effects Cephalosporin none Demicillin none none none Penicillin rash Tetracycline Fever 2004.02.05 - SLIDE 47 2NF Storage Anomalies Removed • Insertion: We can now enter the fact that a particular drug has a particular side effect in the Drug relation. • Deletion: If John White recieves some other drug as a result of the rash from penicillin, but the information on penicillin and rash is maintained. • Update: The side effects for each drug appear only once. IS 257 – Spring 2004 2004.02.05 - SLIDE 48 Boyce-Codd Normal Form • Most 3NF relations are also BCNF relations. • A 3NF relation is NOT in BCNF if: – Candidate keys in the relation are composite keys (they are not single attributes) – There is more than one candidate key in the relation, and – The keys are not disjoint, that is, some attributes in the keys are common IS 257 – Spring 2004 2004.02.05 - SLIDE 49 Most 3NF Relations are also BCNF – Is this one? Patient # Patient Name Patient Address 15 New St. New 1111 John White York, NY 10 Main St. Rye, 1234 Mary Jones NY Charles Dogwood Lane 2345 Brown Harrison, NY 55 Boston Post 4876 Hal Kane Road, Chester, Blind Brook 5123 Paul Kosher Mamaroneck, NY Hilton Road 6845 Ann Hood Larchmont, NY IS 257 – Spring 2004 2004.02.05 - SLIDE 50 BCNF Relations Patient # Patient Name IS 257 – Spring 2004 Patient # 1111 John White 1111 1234 Mary Jones Charles 2345 Brown 1234 4876 Hal Kane 4876 5123 Paul Kosher 5123 6845 Ann Hood 6845 2345 Patient Address 15 New St. New York, NY 10 Main St. Rye, NY Dogwood Lane Harrison, NY 55 Boston Post Road, Chester, Blind Brook Mamaroneck, NY Hilton Road Larchmont, NY 2004.02.05 - SLIDE 51 Fourth Normal Form • Any relation is in Fourth Normal Form if it is BCNF and any multivalued dependencies are trivial • Eliminate non-trivial multivalued dependencies by projecting into simpler tables IS 257 – Spring 2004 2004.02.05 - SLIDE 52 Fifth Normal Form • A relation is in 5NF if every join dependency in the relation is implied by the keys of the relation • Implies that relations that have been decomposed in previous NF can be recombined via natural joins to recreate the original relation. IS 257 – Spring 2004 2004.02.05 - SLIDE 53 Effectiveness and Efficiency Issues for DBMS • Focus on the relational model • Any column in a relational database can be searched for values. • To improve efficiency indexes using storage structures such as BTrees and Hashing are used • But many useful functions are not indexable and require complete scans of the the database IS 257 – Spring 2004 2004.02.05 - SLIDE 54 Example: Text Fields • In conventional RDBMS, when a text field is indexed, only exact matching of the text field contents (or Greater-than and Lessthan). – Can search for individual words using pattern matching, but a full scan is required. • Text searching is still done best (and fastest) by specialized text search programs (Search Engines) that we will look at more later. IS 257 – Spring 2004 2004.02.05 - SLIDE 55 Normalizing to death • Normalization splits database information across multiple tables. • To retrieve complete information from a normalized database, the JOIN operation must be used. • JOIN tends to be expensive in terms of processing time, and very large joins are very expensive. IS 257 – Spring 2004 2004.02.05 - SLIDE 56 Advantages of RDBMS • Possible to design complex data storage and retrieval systems with ease (and without conventional programming). • Support for ACID transactions – Atomic – Consistent – Independent – Durable IS 257 – Spring 2004 2004.02.05 - SLIDE 57 Advantages of RDBMS • Support for very large databases • Automatic optimization of searching (when possible) • RDBMS have a simple view of the database that conforms to much of the data used in businesses. • Standard query language (SQL) IS 257 – Spring 2004 2004.02.05 - SLIDE 58 Disadvantages of RDBMS • Until recently, no real support for complex objects such as documents, video, images, spatial or time-series data. (ORDBMS add support for these). • Often poor support for storage of complex objects from OOP languages (Disassembling the car to park it in the garage) • Still no efficient and effective integrated support for things like text searching within fields. IS 257 – Spring 2004 2004.02.05 - SLIDE 59 Lecture Outline • Review – Database Design -- Object-Oriented Modeling • Logical Design for the Diveshop database • Normalization • Access Database Creation IS 257 – Spring 2004 2004.02.05 - SLIDE 60 Database Creation in Access • Simplest to use a design view – wizards are available, but less flexible • Need to watch the default values • Helps to know what the primary key is, or if one is to be created automatically – Automatic creation is more complex in other RDBMS and ORDBMS • Need to make decision about the physical storage of the data IS 257 – Spring 2004 2004.02.05 - SLIDE 61 Database Creation in Access • Some Simple Examples IS 257 – Spring 2004 2004.02.05 - SLIDE 62 Next Week • More Database Design • Expanding and redesigning DiveShop IS 257 – Spring 2004 2004.02.05 - SLIDE 63