Transcript Referential Integrity and Database Design Recap: From Conceptual Design to Physical

Referential Integrity
and
Database Design Recap: From
Conceptual Design to Physical
Relational Implementation
University of California, Berkeley
School of Information
IS 257: Database Management
IS 257 – Fall 2009
2009-09-22 SLIDE 1
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 2
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 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 – Fall 2009
Physical
Design
2009-09-22 SLIDE 4
Physical Database Design
• The primary goal of physical database
design is data processing efficiency
• We will concentrate on choices often
available to optimize performance of
database services
• Physical Database Design requires
information gathered during earlier stages
of the design process
IS 257 – Fall 2009
2009-09-22 SLIDE 5
Physical Design Decisions
• There are several critical decisions that
will affect the integrity and performance of
the system.
– Storage Format
– Physical record composition
– Data arrangement
– Indexes
– Query optimization and performance tuning
IS 257 – Fall 2009
2009-09-22 SLIDE 6
Objectives of data type selection
•
•
•
•
•
Minimize storage space
Represent all possible values
Improve data integrity
Support all data manipulations
The correct data type should, in minimal
space, represent every possible value (but
eliminated illegal values) for the
associated attribute and can support the
required data manipulations (e.g.
numerical or string operations)
IS 257 – Fall 2009
2009-09-22 SLIDE 7
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 8
Internal Model Access Methods
• Many types of access methods:
– Physical Sequential
– Indexed Sequential
– Indexed Random
– Inverted
– Direct
– Hashed
• Differences in
– Access Efficiency
– Storage Efficiency
IS 257 – Fall 2009
2009-09-22 SLIDE 9
Physical Sequential
• Key values of the physical records are in
logical sequence
• Main use is for “dump” and “restore”
• Access method may be used for storage
as well as retrieval
• Storage Efficiency is near 100%
• Access Efficiency is poor (unless fixed
size physical records)
IS 257 – Fall 2009
2009-09-22 SLIDE 10
Index Sequential
Data File
Actual
Value
IS 257 – Fall 2009
Address
Block
Number
Dumpling
1
Harty
2
Texaci
3
...
…
Adams
Becker
Dumpling
Block 1
Getta
Harty
Block 2
Mobile
Sunoci
Texaci
Block 3
2009-09-22 SLIDE 11
Indexed Sequential: Two Levels
Key
Value
Key
Value
Address
150
1
385
2
001
003
.
.
150
Address
385
7
678
8
805
9
…
Key
Value
Address
536
3
678
4
Key
Value
251
.
.
385
455
480
.
.
536
605
610
.
.
678
Address
785
5
805
6
791
.
.
805
IS 257 – Fall 2009
705
710
.
.
785
2009-09-22 SLIDE 12
Indexed Random
Becker
Harty
Actual
Value
Address
Block
Number
Adams
2
Becker
1
Dumpling
3
Getta
2
Harty
1
Adams
Getta
Dumpling
IS 257 – Fall 2009
2009-09-22 SLIDE 13
Btree
F
B
|| D || F|
|| P || Z|
H || L || P|
R || S || Z|
Devils
Aces
Boilers
Cars
IS 257 – Fall 2009
Flyers
Hawkeyes
Hoosiers
Minors
Panthers
Seminoles
2009-09-22 SLIDE 14
Inverted
CH 145
101, 103,104
Actual
Value
Address
Block
Number
CH 145
1
CS 201
2
CS 623
3
PH 345
…
CS 201
102
Student
name
Course
Number
Adams
CH145
Becker
cs201
Dumpling ch145
Getta
ch145
Harty
cs623
Mobile
cs623
CS 623
105, 106
IS 257 – Fall 2009
2009-09-22 SLIDE 15
Direct
• Key values of the physical records are not
necessarily in logical sequence
• There is a one-to-one correspondence
between a record key and the physical
address of the record
• May be used for storage and retrieval
• Access efficiency always 1
• Storage efficiency depends on density of
keys
• No duplicate keys permitted
IS 257 – Fall 2009
2009-09-22 SLIDE 16
Hashing
• Key values of the physical records are not
necessarily in logical sequence
• Many key values may share the same physical
address (block)
• May be used for storage and retrieval
• Access efficiency depends on distribution of
keys, algorithm for key transformation and space
allocated
• Storage efficiency depends on distibution of
keys and algorithm used for key transformation
IS 257 – Fall 2009
2009-09-22 SLIDE 17
Comparative Access Methods
Factor
Storage space
Sequential
retrieval on
primary key
Random Retr.
Multiple Key
Retr.
Deleting records
Sequential
No wasted space
Indexed
Hashed
No wasted
space for data
but extra space for index
more space needed for
addition and deletion of
records after initial load
Very fast
Moderately Fast
Impractical
Moderately Fast
Very fast with
multiple indexes
OK if dynamic
Very fast
OK if dynamic
very easy
Easy but requires
Maintenance of
indexes
very easy
Impractical
Possible but needs
a full scan
can create wasted
space
Adding records requires rewriting
file
Updating records usually requires
rewriting file
IS 257 – Fall 2009
Not possible
very easy
2009-09-22 SLIDE 18
Late addition – Bitmap index
• Uses a single bit to represent whether or
not a particular record has a specific value
IS 257 – Fall 2009
2009-09-22 SLIDE 19
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 20
Indexes
• Most database applications require:
– locating rows in tables that match some
condition (e.g. SELECT operations)
– Joining one table with another based on
common values of attributes in each table
• Indexes can greatly speed up these
processes and avoid having to do
sequential scanning of database tables to
resolve queries
IS 257 – Fall 2009
2009-09-22 SLIDE 21
Primary Key Indexes
• In Access -- this will be created
automatically when a field is selected as
primary key
– in the table design view select an attribute row
(or rows) and clock on the key symbol in the
toolbar.
– The index is created automatically as one with
(No Duplicates)
• In SQL
– CREATE UNIQUE INDEX indexname ON
tablename(attribute);
IS 257 – Fall 2009
2009-09-22 SLIDE 22
Secondary Key Indexes
• In Access -- Secondary key indexes can
be created on any field.
– In the table design view, select the attribute to
be indexed
– In the “Indexed” box on the General field
description information at the bottom of the
window, select “Yes (Duplicates OK)”
• In SQL
– CREATE INDEX indxname on tablename(attribute);
IS 257 – Fall 2009
2009-09-22 SLIDE 23
When to Index
• Tradeoff between time and space:
– Indexes permit faster processing for searching
– But they take up space for the index
– They also slow processing for insertions, deletions,
and updates, because both the table and the index
must be modified
• Thus they SHOULD be used for databases
where search is the main mode of interaction
• The might be skipped if high rates of updating
and insertions are expected, and access or
operations are rare
IS 257 – Fall 2009
2009-09-22 SLIDE 24
When to Use Indexes
• Rules of thumb
– Indexes are most useful on larger tables
– Specify a unique index for the primary key of each
table (automatically done for many DBMS)
– Indexes are most useful for attributes used as search
criteria or for joining tables
– Indexes are useful if sorting is often done on the
attribute
– Most useful when there are many different values for
an attribute
– Some DBMS limit the number of indexes and the size
of the index key values
– Some indexes will not retrieve NULL values
IS 257 – Fall 2009
2009-09-22 SLIDE 25
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 26
Parallel Processing with RAID
• In reading pages from secondary storage,
there are often situations where the DBMS
must retrieve multiple pages of data from
storage -- and may often encounter
– rotational delay
– seek positioning delay
•
in getting each page from the disk
IS 257 – Fall 2009
2009-09-22 SLIDE 27
Disk Timing (and Problems)
Rotational Delay
Seek Positioning
Delay
Hair
Read Head
fingerprint
IS 257 – Fall 2009
2009-09-22 SLIDE 28
RAID
• Provides parallel disks (and software) so
that multiple pages can be retrieved
simultaneously
• RAID stands for “Redundant Arrays of
Inexpensive Disks”
– invented by Randy Katz and Dave Patterson
here at Berkeley
• Some manufacturers have renamed the
“inexpensive” part (for obvious reasons)
IS 257 – Fall 2009
2009-09-22 SLIDE 29
RAID Technology
One logical disk drive
Parallel
Writes
Disk 1
Disk 2
Disk 3
Disk 4
1
5
2
6
3
7
4
8
9
*
*
*
10
*
*
*
11
*
*
*
12
*
*
*
Stripe
Stripe
Stripe
Parallel
Reads
IS 257 – Fall 2009
2009-09-22 SLIDE 30
Raid 0
One logical disk drive
Parallel
Writes
Disk 1
Disk 2
Disk 3
Disk 4
1
5
2
6
3
7
4
8
9
*
*
*
10
*
*
*
11
*
*
*
12
*
*
*
Stripe
Stripe
Stripe
Parallel
Reads
IS 257 – Fall 2009
2009-09-22 SLIDE 31
RAID-1
Parallel
Writes
Disk 1
Disk 2
Disk 3
Disk 4
1
3
1
3
2
4
2
4
5
*
*
*
5
*
*
*
6
*
*
*
6
*
*
*
Stripe
Stripe
Stripe
Parallel
Reads
Raid 1 provides full redundancy for any data stored
IS 257 – Fall 2009
2009-09-22 SLIDE 32
RAID-2
Writes span all drives
Disk 1
Disk 2
Disk 3
Disk 4
1a
2a
1b
2b
ecc ecc
ecc ecc
3a
*
*
*
3b
*
*
*
ecc ecc
*
*
*
*
*
*
Stripe
Stripe
Stripe
Reads span all drives
Raid 2 divides blocks across multiple disks with error correcting codes
IS 257 – Fall 2009
2009-09-22 SLIDE 33
RAID-3
Writes span all drives
Disk 1
Disk 2
Disk 3
Disk 4
1a
2a
1b
2b
1c
2c
ecc
ecc
3a
*
*
*
3b
*
*
*
3c
*
*
*
ecc
*
*
*
Stripe
Stripe
Stripe
Reads span all drives
Raid 3 divides very long blocks across multiple disks with a single drive for ECC
IS 257 – Fall 2009
2009-09-22 SLIDE 34
Raid-4
Parallel
Writes
Disk 1
Disk 2
Disk 3
Disk 4
1
4
2
5
3
6
ecc
ecc
7
*
*
*
8
*
*
*
9
*
*
*
ecc
*
*
*
Stripe
Stripe
Stripe
Parallel
Reads
Raid 4 like Raid 3 for smaller blocks with multiple blocks per stripe
IS 257 – Fall 2009
2009-09-22 SLIDE 35
RAID-5
Parallel
Writes
Disk 1
Disk 2
1
5
9
*
*
ecc
2
6
10
*
*
ecc
Disk 3
3
7
11
*
*
ecc
Disk 4
4
8
12
*
*
ecc
Stripe
Stripe
Stripe
Parallel
Reads
Raid 5 divides blocks across multiple disks with error correcting codes
IS 257 – Fall 2009
2009-09-22 SLIDE 36
RAID for DBMS
• What works best for Database storage?
• RAID-1 is best when 24/7 fault tolerant
processing is needed
• RAID-5 is best for read-intensive
applications with very large data sets
IS 257 – Fall 2009
2009-09-22 SLIDE 37
Lecture Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 38
Integrity Constraints
• The constraints we wish to impose in order
to protect the database from becoming
inconsistent.
• Five types
– Required data
– attribute domain constraints
– entity integrity
– referential integrity
– enterprise constraints
IS 257 – Fall 2009
2009-09-22 SLIDE 39
Required Data
• Some attributes must always contain a
value -- they cannot have a null
• For example:
– Every employee must have a job title.
– Every diveshop diveitem must have an order
number and an item number.
IS 257 – Fall 2009
2009-09-22 SLIDE 40
Attribute Domain Constraints
• Every attribute has a domain, that is a set
of values that are legal for it to use.
• For example:
– The domain of sex in the employee relation is
“M” or “F”
• Domain ranges can be used to validate
input to the database.
IS 257 – Fall 2009
2009-09-22 SLIDE 41
Entity Integrity
• The primary key of any entity cannot be
NULL.
IS 257 – Fall 2009
2009-09-22 SLIDE 42
Referential Integrity
• A “foreign key” links each occurrence in a
relation representing a child entity to the
occurrence of the parent entity containing the
matching candidate key
• Referential Integrity means that if the foreign key
contains a value, that value must refer to an
existing occurrence in the parent entity
• For example:
– Since the Order ID in the diveitem relation refers to a
particular diveords item, that item must exist for
referential integrity to be satisfied
IS 257 – Fall 2009
2009-09-22 SLIDE 43
Referential Integrity
• Referential integrity options are declared
when tables are defined (in most systems)
• There are many issues having to do with
how particular referential integrity
constraints are to be implemented to deal
with insertions and deletions of data from
the parent and child tables.
IS 257 – Fall 2009
2009-09-22 SLIDE 44
Insertion rules
• A row should not be inserted in the
referencing (child) table unless there
already exists a matching entry in the
referenced table.
• Inserting into the parent table should not
cause referential integrity problems
– Unless it is itself a child…
• Sometimes a special NULL value may be
used to create child entries without a
parent or with a “dummy” parent.
IS 257 – Fall 2009
2009-09-22 SLIDE 45
Deletion rules
• A row should not be deleted from the
referenced table (parent) if there are
matching rows in the referencing table
(child).
• Three ways to handle this
– Restrict -- disallow the delete
– Nullify -- reset the foreign keys in the child to
some NULL or dummy value
– Cascade -- Delete all rows in the child where
there is a foreign key matching the key in the
parent row being deleted
IS 257 – Fall 2009
2009-09-22 SLIDE 46
Referential Integrity
• This can be implemented using external
programs that access the database
• newer databases implement executable
rules or built-in integrity constraints (e.g.
Access)
IS 257 – Fall 2009
2009-09-22 SLIDE 47
Enterprise Constraints
• These are business rule that may affect
the database and the data in it
– for example, if a manager is only permitted to
manage 10 employees then it would violate
an enterprise constraint to manage more
IS 257 – Fall 2009
2009-09-22 SLIDE 48
Outline
• Review
– Physical Database Design
– Access Methods
– Indexes and What to index
– Parallel storage systems (RAID)
• Integrity constraints
• Database Design Process Recap
IS 257 – Fall 2009
2009-09-22 SLIDE 49
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 – Fall 2009
2009-09-22 SLIDE 50
Today: New Design
• Today we will build the COOKIE database
from (rough) needs assessment through
the conceptual model, logical model and
finally physical implementation in Access.
IS 257 – Fall 2009
2009-09-22 SLIDE 51
Cookie Requirements
• Cookie is a bibliographic database that contains
information about a hypothetical union catalog of
several libraries.
• Need to record which books are held by which
libraries
• Need to search on bibliographic information
– Author, title, subject, call number for a given library,
etc.
• Need to know who publishes the books for
ordering, etc.
IS 257 – Fall 2009
2009-09-22 SLIDE 52
Cookie Database
• There are currently 6 main types of entities in
the database
– Authors (Authors)
• Note: we created authors from the former design when
talking about normalization (two weeks ago)
–
–
–
–
–
–
Books (bibfile)
Local Call numbers (callfile)
Libraries (libfile)
Publishers (pubfile)
Subject headings (subfile)
Additional entities
• Links between subject and books (indxfile)
• Links between authors and books (AU_BIB)
IS 257 – Fall 2009
2009-09-22 SLIDE 53
AUTHORS
• Author -- The author’s name (We do not
distinguish between Personal and
Corporate authors)
• Au_id – a unique id for the author
IS 257 – Fall 2009
2009-09-22 SLIDE 54
AUTHORS
AU ID
Author
Authors
IS 257 – Fall 2009
2009-09-22 SLIDE 55
BIBFILE
• Books (BIBFILE) contains information about
particular books. It includes one record for each
book. The attributes are:
–
–
–
–
–
–
–
–
accno -- an “accession” or serial number
title -- The title of the book
loc -- Location of publication (where published)
date -- Date of publication
price -- Price of the book
pagination -- Number of pages
ill -- What type of illustrations (maps, etc) if any
height -- Height of the book in centimeters
IS 257 – Fall 2009
2009-09-22 SLIDE 56
Books/BIBFILE
Title
accno
Loc
Price
Books
Date
Pagination
Ill
Height
IS 257 – Fall 2009
2009-09-22 SLIDE 57
CALLFILE
• CALLFILE contains call numbers and
holdings information linking particular
books with particular libraries. Its attributes
are:
– accno -- the book accession number
– libid -- the id of the holding library
– callno -- the call number of the book in the
particular library
– copies -- the number of copies held by the
particular library
IS 257 – Fall 2009
2009-09-22 SLIDE 58
LocalInfo/CALLFILE
libid
Callno
accno
Copies
CALLFILE
IS 257 – Fall 2009
2009-09-22 SLIDE 59
LIBFILE
• LIBFILE contain information about the libraries
participating in this union catalog. Its attributes
include:
–
–
–
–
–
–
–
–
libid -- Library id number
library -- Name of the library
laddress -- Street address for the library
lcity -- City name
lstate -- State code (postal abbreviation)
lzip -- zip code
lphone -- Phone number
mop - suncl -- Library opening and closing times for
each day of the week.
IS 257 – Fall 2009
2009-09-22 SLIDE 60
Libraries/LIBFILE
lstate
laddress
lcity
lzip
Library
lphone
Libid
SatCl
LIBFILE
SunOp
SatOp
Suncl
FCl
MOp
FOp
ThCl
Mcl
TuOp
IS 257 – Fall 2009
TuCl
WOp
WCl
ThOp
2009-09-22 SLIDE 61
PUBFILE
• PUBFILE contain information about the
publishers of books. Its attributes include
– pubid -- The publisher’s id number
– publisher -- Publisher name
– paddress -- Publisher street address
– pcity -- Publisher city
– pstate -- Publisher state
– pzip -- Publisher zip code
– pphone -- Publisher phone number
– ship -- standard shipping time in days
IS 257 – Fall 2009
2009-09-22 SLIDE 62
Publisher/PUBFILE
paddress
Publisher
pcity
PUBFILE
pubid
pstate
pzip
Ship
pphone
IS 257 – Fall 2009
2009-09-22 SLIDE 63
SUBFILE
• SUBFILE contains each unique subject
heading that can be assigned to books. Its
attributes are
– subcode -- Subject identification number
– subject -- the subject heading/description
IS 257 – Fall 2009
2009-09-22 SLIDE 64
Subjects/SUBFILE
subid
Subject
SUBFILE
IS 257 – Fall 2009
2009-09-22 SLIDE 65
INDXFILE
• INDXFILE provides a way to allow manyto-many mapping of subject headings to
books. Its attributes consist entirely of links
to other tables
– subcode -- link to subject id
– accno -- link to book accession number
IS 257 – Fall 2009
2009-09-22 SLIDE 66
Linking Subjects and Books
subid
ACCNO
INDXFILE
IS 257 – Fall 2009
2009-09-22 SLIDE 67
AU_BIB
• AU_BIB provides a way to allow many to
many mapping between books and
authors. It also consists only of links to
other tables
– AU_ID – link to the AUTHORS table
– ACCNO – link to the BIBFILE table
IS 257 – Fall 2009
2009-09-22 SLIDE 68
Linking Authors and Books
AU ID
ACCNO
AU_BIB
IS 257 – Fall 2009
2009-09-22 SLIDE 69
Some examples of Cookie Searches
• Who wrote Microcosmographia Academica?
• How many pages long is Alfred Whitehead’s The Aims of Education
and Other Essays?
• Which branches in Berkeley’s public library system are open on
Sunday?
• What is the call number of Moffitt Library’s copy of Abraham
Flexner’s book Universities: American, English, German?
• What books on the subject of higher education are among the
holdings of Berkeley (both UC and City) libraries?
• Print a list of the Mechanics Library holdings, in descending order by
height.
• What would it cost to replace every copy of each book that contains
illustrations (including graphs, maps, portraits, etc.)?
• Which library closes earliest on Friday night?
IS 257 – Fall 2009
2009-09-22 SLIDE 70
Cookie ER Diagram
pubid
accno
BIBFILE
CALLFILE
accno
accno
AU_BIB
LIBFILE
libid
libid
AU ID
PUBFILE
INDXFILE
pubid
SUBFILE
AUTHORS
accno
AU_ID
subcode
subcode
Note: diagram
contains only
attributes used
for linking
Author
IS 257 – Fall 2009
2009-09-22 SLIDE 71
What Problems?
• What sorts of problems and missing
features arise given the previous ER
diagram?
IS 257 – Fall 2009
2009-09-22 SLIDE 72
Problems Identified
•
•
•
•
•
•
•
•
Subtitles, parallel titles?
Edition information
Series information
lending status
material type designation
Genre, class information
Better codes (ISBN?)
Missing information
(ISBN)
IS 257 – Fall 2009
• Authority control for
authors
• Missing/incomplete data
• Data entry problems
• Ordering information
• Illustrations
• Subfield separation (such
as last_name, first_name)
• Separate personal and
corporate authors
2009-09-22 SLIDE 73
Problems (Cont.)
• Location field
inconsistent
• No notes field
• No language field
• Zipcode doesn’t
support plus-4
• No publisher shipping
addresses
IS 257 – Fall 2009
• No (indexable)
keyword search
capability
• No support for
multivolume works
• No support for URLs
– to online version
– to libraries
– to publishers
2009-09-22 SLIDE 74
Original Cookie ER Diagram
pubid
accno
BIBFILE
CALLFILE
accno
accno
AU_BIB
LIBFILE
libid
libid
AU ID
PUBFILE
INDXFILE
pubid
SUBFILE
AUTHORS
accno
AU_ID
subcode
subcode
Note: diagram
contains only
attributes used
for linking
Author
IS 257 – Fall 2009
2009-09-22 SLIDE 75
Cookie2: Separate Name Authorities
pubid
accno
BIBFILE
CALLFILE
accno
accno
AUTHBIB
LIBFILE
libid
libid
authid
PUBFILE
authtype
INDXFILE
pubid
SUBFILE
AUTHFILE
accno
authid
subcode
subcode
name
nameid
IS 257 – Fall 2009
2009-09-22 SLIDE 76
Cookie 3: Keywords
termid
accno termid
pubid
accno
BIBFILE
accno
AUTHBIB
KEYMAP
TERMS
CALLFILE
LIBFILE
accno
libid
authid
libid
PUBFILE
authtype
INDXFILE
pubid
SUBFILE
AUTHFILE
authid
name
accno
subcode
subcode
nameid
IS 257 – Fall 2009
2009-09-22 SLIDE 77
Cookie 4: Series
ser_title
SERIES
seriesid
termid
accno termid
seriesid
pubid
accno
BIBFILE
accno
AUTHBIB
KEYMAP
TERMS
CALLFILE
LIBFILE
accno
libid
authid
libid
PUBFILE
authtype
INDXFILE
pubid
SUBFILE
AUTHFILE
authid
name
accno
subcode
subcode
nameid
IS 257 – Fall 2009
2009-09-22 SLIDE 78
Cookie 5: Circulation
ser_title
SERIES
seriesid
pubid
KEYMAP
TERMS
CALLFILE
LIBFILE
accno
BIBFILE
accno
termid
accno termid
seriesid
accno
circid
libid
libid
AUTHBIB authid
PUBFILE
pubid
authtype
AUTHFILE
authid
nameid
name
IS 257 – Fall 2009
INDXFILE
SUBFILE
accno subcode
subcode
PATRON
CIRC
copynum patronid
circid
2009-09-22 SLIDE 79
Logical Model: Mapping to Relations
• Take each entity
– Authors
– BIBFILE
– LIBFILE
– CALLFILE
– SUBFILE
– PUBFILE
– INDXFILE
– AU_BIB
• And make it a table...
IS 257 – Fall 2009
2009-09-22 SLIDE 80
Implementing the Physical Database...
• For each of the entities, we will build a
table…
• Start up access…
• Use “New” in Tables…
• Loading data
• Entering data
• Data entry forms
IS 257 – Fall 2009
2009-09-22 SLIDE 81
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 – Fall 2009
2009-09-22 SLIDE 82
Next Time
•
•
•
•
Relational Operations
Relational Algebra
Relational Calculus
Introduction to SQL
IS 257 – Fall 2009
2009-09-22 SLIDE 83