189 lines
5.7 KiB
Markdown
189 lines
5.7 KiB
Markdown
##### Project:
|
|
::PROJECTNAME
|
|
|
|
##### Internal Release Number:
|
|
::X.Y.Z
|
|
|
|
##### Related Documents:
|
|
- [Design](Design) > Design Persistence
|
|
- ::LINKS TO RELEVANT STANDARDS
|
|
- ::LINKS TO OTHER DOCUMENTS
|
|
|
|
---
|
|
|
|
### Overview
|
|
|
|
*TODO: Answer the questions below to help you design needed persistence
|
|
features. Some example text is provided. Add or delete text as needed.*
|
|
|
|
#### What are the most important facts that a developer should know about persistent data storage in this system?
|
|
::PARAGRAPH OR BULLETS
|
|
|
|
#### What are the ranked goals for persistence in this system?
|
|
|
|
1. ::[Expressiveness](Glossary-Std#dg_expressiveness)
|
|
2. ::[Ease of access](Glossary-Std#dg_easy_access)
|
|
3. ::[Reliability](Glossary-Std#dg_data_reliability)
|
|
4. ::[Data capacity](Glossary-Std#dg_data_capacity)
|
|
5. ::[Data security](Glossary-Std#dg_data_security)
|
|
6. ::[Performance](Glossary-Std#dg_data_performance)
|
|
7. ::[Interoperability](Glossary-Std#dg_data_interop)
|
|
|
|
### Central Database
|
|
|
|
#### What is the logical database design?
|
|
|
|
::The logical database design is described in this [UML
|
|
model](LINK-TO-MODEL) or this [ER diagram](LINK-TO-DIAGRAM).
|
|
|
|
::Additional logical constraints on the database are:
|
|
|
|
- ::Students can repeat a course (and thus have two records for the
|
|
same course in their transcript), if and only if they got a
|
|
grade of "C-" or lower, or the course number is 198, 199, 298,
|
|
or 299.
|
|
- ::A grade of "A+" is valid only for transcript entries during or
|
|
after Fall 1990. Prior to that term, the highest possible grade
|
|
was an "A".
|
|
- ::LOGICAL CONSTRAINT THAT CANNOT BE EXPRESSED IN THE DIAGRAM
|
|
- ::LOGICAL CONSTRAINT THAT CANNOT BE EXPRESSED IN THE DIAGRAM
|
|
|
|
#### What are the physical tables and views?
|
|
|
|
::The physical database design is described in this [UML
|
|
model](LINK-TO-MODEL) or this [ER diagram](LINK-TO-DIAGRAM).
|
|
|
|
#### How will objects in the application be stored in the database?
|
|
|
|
::We will use one database table for each class, and one row in the
|
|
database for each persistent instance of that class.
|
|
|
|
::We will use a [library](LINK-TO-LIBRARY) to do our
|
|
object-relational mapping. (E.g., torque, castor, JDO,
|
|
ADO, hibernate)
|
|
|
|
#### What database access controls will be used?
|
|
|
|
::A database user account has been created that has access to the
|
|
needed application database tables. The username and password for
|
|
this account is stored in a configuration file read by the
|
|
application server. The database limits login by that user to only
|
|
the IP-address used by the application server.
|
|
|
|
#### Is this application's central database accessible to other applications?
|
|
|
|
::Yes. The database is an important point of interoperability for new
|
|
applications to be added later. The database itself provides support
|
|
for access controls and checks validity constraints so that a
|
|
defective application cannot corrupt the database.
|
|
|
|
::No. This database should always be accessed through
|
|
this application. All relevant pieces of information are available
|
|
through the application interfaces. The database itself does not
|
|
protect against data corruption that could be caused by
|
|
other applications.
|
|
|
|
### File Storage
|
|
|
|
#### What data needs to be stored in files?
|
|
|
|
::Nothing is stored in files, everything is in the database.
|
|
|
|
::The server stores most data in the database, but mailing list
|
|
attachments are written to files on the server hard disk.
|
|
|
|
::All user documents are stored in files on their computer hard disk.
|
|
|
|
#### What are the conventions for directory structure and file naming?
|
|
|
|
::N/A
|
|
|
|
::Files are stored on the server as
|
|
|
|
```/var/data/attachments/msgNNNN-MMM.dat```
|
|
|
|
::Users store files anywhere on their computer, with the filename
|
|
extension ```.TST```.
|
|
|
|
#### What file system access controls will be used?
|
|
|
|
::N/A
|
|
|
|
::Files for message attachments are only readable and writable by the
|
|
mailing list archiving process that runs as operating system
|
|
user "archdaemon".
|
|
|
|
::Users can use whatever file permissions they like.
|
|
|
|
#### What file format will be used?
|
|
|
|
::The [XYZ](LINK-TO-STANDARD) standard file format.
|
|
|
|
::A java .properties file.
|
|
|
|
::A window's .ini file.
|
|
|
|
::An XML file using [this DTD file](LINK-TO-DTD).
|
|
|
|
::A simple text file with the following format: ...
|
|
|
|
::A custom binary file in the following format: ...
|
|
|
|
### Distributed Storage
|
|
|
|
#### What information (if any) will be stored on client machines? For how long?
|
|
|
|
::A cookie will be stored on the user machine for the purpose of
|
|
identifying a user session. When the user logs out or closes their
|
|
web browser, the cookie is deleted. Most browsers will not even
|
|
write this cookie to the disk.
|
|
|
|
::The a cookie is stored on the user's computer that is equivalent to
|
|
their password (but it is NOT actually their password). This cookie
|
|
is needed for the auto-login feature. The cookie lasts a maximum of
|
|
30 days, and it can only be used from the same IP address.
|
|
|
|
::User preferences for color scheme are stored in cookies in
|
|
their browser. This information is not at all sensitive, so it is
|
|
kept indefinitely.
|
|
|
|
::All the user data will be stored on files on their computers.
|
|
|
|
### Persistence Mechanisms Checklist
|
|
|
|
|
|
#### Expressiveness: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Ease of access: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Reliability: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Capacity: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Security: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Performance: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Interoperability: To what extent has this been achieved?
|
|
|
|
::2-4 SENTENCES
|
|
|
|
#### Has the persistence design been communicated to the development team and other stakeholders?
|
|
|
|
::Yes, everyone understands. Feedback is welcome.
|
|
|
|
::No, this is a risk that is noted in the [Risk Management](Project-Plan#risks)
|
|
section.
|