An Improved Approach to Generating Configuration Files from a Database - PowerPoint PPT Presentation

An Improved Approach to Generating Configuration Files from a Database

Jon Finke

Rensselaer Polytechnic Institute

• Cuts development time
• Standard development environment
• Host interface written once
• Code sharing with web routines
• All work done centrally
• PL/SQL well integrated to Database
• Platform independence

• Custom program for each file type.
• Common file system
• Small number of platforms
• Standard development environment
• Lots of cut and paste C coding
• Direct access to tables and views

SQL*NET

SQL*NET

File Format Logic

File Format Logic

Version Control

Version Control

Relational Database

• Loss of common file system
• Harder to distribute custom programs
• Multiple development environments
• Program logic unavailable to web applications.
• Minor file format changes require too much work.

Relational Database

File Format Logic

File Format Logic

File Format Logic

Switcher

SQL*NET

SQL*NET

Version Control

Version Control

• File format logic stored in DB
• Changes made centrally
• Generic file extraction program
• No changes after installation
• Platform independence
• Code sharing with web applications
• PL/SQL programs are shorter
• Faster to write

• PL/SQL
• Procedural extension to SQL
• Simple Procedure or Function
• Package
• Set of procedures and functions
• maintains state
• Stored and executed by database server

• Variables and Constants
• SQL built in functions
• String, Numeric, Date
• Conditionals
• Looping Constructs
• Exception Handling
• Records

Get Filename

Start

Null?

Done

Version?

Open File

Get Line

Null?

Write Line

• Standard API for generic program
• Provides access control
• Provide filename for simple cases
• Also direction, and other attributes
• Grouping of multiple simple files
• Environment info for specific file generator routines.

Return

Null

Get_Filename

Record?

Get Next

Target Rec

Files>0?

Open?

Access

OK?

Return

Error

Open

Target Rec

Simple?

Return

Rec.Filename

Return

Rec.GetFname()

• Target Name, Sequence Number
• Access List
• Get Data Routine Name
• Get FileName Routine Name (C)
• FileName (S)
• Direction, DBMS_OUT Flag (S)
• Version Info (S)

Cursor Get_Records is

Select Username, Uid Gid, Gecos, Shell, Path from Logins;

. . .

Procedure Get_Data(Result out varchar2) is

R Get_Records%RowType

begin

if not Get_Records%IsOpen

then

Open Get_Records;

end if;

Fetch Get_Records into R;

if Get_Records%NotFound

then

Close Get_Records;

Result := Null;

else

Result := R.Username || ‘:*:’ || R.Uid || ‘:’

|| R.Gid || ‘:’ || R.Gecos || ‘:’ || R.Path

|| ‘:’ || R.shell;

end if;

return;

• Get_FileName
• Like Get_Data
• Stashes context info for Get_Data
• Provides version info (optionally)
• Keep calling until no more files.
• For each file, call Get_Data until no more data.

• Replacing existing custom programs
• Loading data as well as extraction
• Handler for back end processing
• File “STDOUT”
• Wish I had done this long ago

File Gen

Web Server

WP File

WP Web

WP Table Routines

Relational Database Tables

• White Pages
• LaTeX, HTML, LDIF, ph, CSV
• Hostmaster
• Resource Record (bind)
• Hostfile
• DHCP Config
• TSM Billing
• Error Reports

• TSM (Backup/archive)
• Accounting Records
• White Pages
• CSV staff list (remote campus)
• Terminal Server
• Accounting logs
• lpd (printing)
• Accounting logs

• GET from program
• PUT to program
• Boilerplate management
• Call file generation from Web
• Faster development for web pages
• Alternate Boilerplate testing
• More platforms

An Improved Approach to Generating Configuration Files from a Database

Jon Finke

Rensselaer Polytechnic Institute

finkej@rpi.edu

http://www.rpi.edu/~finkej