Upload
hagen
View
50
Download
0
Embed Size (px)
DESCRIPTION
Making Database Systems Usable. University of Michigan H.V. Jagadish, Adriane Chapman, Aaron Elkiss, Magesh Jayapandian, Yunyao Li, Arnab Nandi, Cong Yu. Agenda. Users Expectations The Persistence of Pain The Painless Future Conclusion Q&A. Users Expectations Database interactions. - PowerPoint PPT Presentation
Citation preview
Mar 27, 2008 Christiano Santiago 1
Making Database Systems Usable
University of MichiganH.V. Jagadish, Adriane Chapman, Aaron Elkiss, Magesh Jayapandian, Yunyao Li, Arnab Nandi, Cong Yu
Mar 27, 2008 Christiano Santiago 2
Agenda
Users Expectations The Persistence of Pain The Painless Future Conclusion Q&A
Mar 27, 2008 Christiano Santiago 3
Users ExpectationsDatabase interactions
Ability to query in a more sophisticated way, using complex query semantics
More precise and complete answers
Expectation of structure in the result set
Create and update databases
Mar 27, 2008 Christiano Santiago 4
The Persistence Of Pain
Mar 27, 2008 Christiano Santiago 5
Higher Level Presentation Data ModelPainful Relations
Mar 27, 2008 Christiano Santiago 6
Higher Level Presentation Data ModelPainful Relations
Simple concept versus Implementation
Flight info
X
Mar 27, 2008 Christiano Santiago 7
Higher Level Presentation Data ModelPainful Relations
SELECT s.departure_timeFROM schedule AS s,flight_info AS f, airports AS d, airports AS aWHERE s.id = f.schedule_id AND f.fid = d.id AND d.city_name = “Beijing” AND f.tid = a.id AND a.city_name = “Detroit”
What are the fligth departure times from Detroit to Beijing?
Mar 27, 2008 Christiano Santiago 8
Higher Level Presentation Data ModelPainful Relations
Problems Large number of table Poorly named entities Poorly named fields Joins are not intuitive Recursive self-joins SQL is too onerous Dependency on DBA (please don’t leave!)
Mar 27, 2008 Christiano Santiago 9
Multiple Ways to Access DataPainful Options
Mar 27, 2008 Christiano Santiago 10
Multiple Ways to Access DataPainful Options
Too much functionality and too many options
X
Mar 27, 2008 Christiano Santiago 11
Multiple Ways to Access DataPainful Options
Barry Schwartz, The tyranny of choice.
Scientific American, April 2004, pp. 71-75
Mar 27, 2008 Christiano Santiago 12
Multiple Ways to Access DataPainful Options
Perspectives Design systems for customized value Care about how well uses can get their job
done Forms-based interfaces have been the
primary means to interact with databases Provide simple querying tools for novice
users and powerful tools for experts (customization)
Mar 27, 2008 Christiano Santiago 13
Precision and RecallUnexpected Pain
Mar 27, 2008 Christiano Santiago 14
Precision and RecallUnexpected Pain
X
Mar 27, 2008 Christiano Santiago 15
Search engines error acceptance Expectations are set correctly Usually top few results do contain something
relevant If no relevant results were found, search it
again The web is so huge that no one knows
exactly what is out there
Precision and RecallUnexpected Pain
Mar 27, 2008 Christiano Santiago 16
Mar 27, 2008 Christiano Santiago 17
Unable to query Systems may impede users from querying the way they want Scenario: world traveler with infinite flexibility and many
destinations to visit
Precision and RecallUnexpected Pain
X
Mar 27, 2008 Christiano Santiago 18
Precision and RecallUnexpected Pain
Unable to query User’s versus form designer’s mental model of the data.
Users should be worried about how. They just need the what.
Challenge #1: it’s not easy to provide a straightforward and comprehensive way of specifying what a user wants when a query requires aggregation or multiple complex joins.
Challenge #2: performance, security access level, data or program errors may prevent users from running a query.
Mar 27, 2008 Christiano Santiago 19
Unexpected results (Unexpected results) + (no explanation) = frustration
Precision and RecallUnexpected Pain
Example 1Example 1• The client record shows he has 2 cars
but• There is only 1 car related to this client in the
database.# of cars was a field in the Client table, with no referential
Integrity with CarOwner table
Mar 27, 2008 Christiano Santiago 20
Unexpected results (Unexpected results) + (no explanation) = frustration
Precision and RecallUnexpected Pain
Example 2Example 2User is looking for cheap flights provided by her favorite airline:• Los Angeles for $75• Boston for $100• San Francisco for $400 (?)
$400 was less than half the average price for a ticket to San Francisco
Mar 27, 2008 Christiano Santiago 21
Precision and RecallUnexpected Pain
Unexpected results Empty & non-empty results Users may need to know where a result
comes from Users may need to know why a result is
returned System’s usability can be significantly
affected when no explanation can be given
Mar 27, 2008 Christiano Santiago 22
Errors In Query ConstructionUnseen Pain
Mar 27, 2008 Christiano Santiago 23
Errors In Query ConstructionUnseen Pain
Database Users versus Computer Scientists
X
Mar 27, 2008 Christiano Santiago 24
Errors In Query ConstructionUnseen Pain
Mar 27, 2008 Christiano Santiago 25
Errors In Query ConstructionUnseen Pain
Perspectives Query purpose: provide information that the
user doesn’t have How do I provide a clear and precise “from”
and “where” clause, if I don’t know the possibilities?
WYSIWYG
Mar 27, 2008 Christiano Santiago 26
Errors In Query ConstructionUnseen Pain
WYISWYG
Assisted Querying using Instant-Response InterfacesArnab Nandi & H. V. Jagadish - University of Michigan
Mar 27, 2008 Christiano Santiago 27
Errors In Query ConstructionUnseen Pain
WYISWYG Google Earth approach Can you image finding a location in a map
using coordinates instead of zoom and rotation?
Mar 27, 2008 Christiano Santiago 28
Database CreationBirthing pain
Mar 27, 2008 Christiano Santiago 29
Database CreationBirthing pain
Corporate Market versus Average User
X
Mar 27, 2008 Christiano Santiago 30
Database CreationBirthing pain
Perspectives Users want to store their data into databases
but this is not an easy task Database schema Table structure Normalization Relationships Constraints
Mar 27, 2008 Christiano Santiago 31
Database CreationBirthing pain
Perspectives An everyday database
No clear view of required database structure No comprehensive design at starting point Structure grows as time passes
Structure grows incrementally Need to support both structured and
unstructured information
Mar 27, 2008 Christiano Santiago 32
The Painless Future
Mar 27, 2008 Christiano Santiago 33
The Painless FutureGeographic Model
Joins between data sets using geographic or spatial location as the basis
Mar 27, 2008 Christiano Santiago 34
The Painless FutureNetwork Model
Graph or network representation of data.
Mar 27, 2008 Christiano Santiago 35
The Painless FutureMultidimensional Model
Data as points in multi-dimensional space
Mar 27, 2008 Christiano Santiago 36
The Painless FutureTabular Model
People is used to seeing data represented in simple two-dimensional tables
Mar 27, 2008 Christiano Santiago 37
The Painless FuturePresentation Data Models
Perspectives Data manipulation through presentation data model versus view
updates
Consistency among view options: geographic and textual views in synchrony
Data provenance: “why” and “where” related to result sets
Direct data manipulation Point-and-click, drag-and-drop, etc. New few number of algebra operators to support it
Schema-later (unstructured) and heterogeneous database design
Mar 27, 2008 Christiano Santiago 38
Conclusion
Databases are extremely difficult for most people to interact with.
We must rethink the architecture of the database systems as a whole.
Presentation model as a distinct layer above usual logical data model.
Mar 27, 2008 Christiano Santiago 39
Questions & Answers