Welcome to one of the most useful, and surprisingly fun, learning tools in your IBM i journey. In this lesson, we explore ALLFILE.PF, a physical file designed to showcase every major DDS-supported field type in one place. If you’ve ever wondered, “What data types does DDS actually support?” or “How do packed, zoned, binary, float, date, time, and LOB fields look in real DDS?” this is your hands‑on reference.
This file is intentionally comprehensive. It’s not meant to model a real business table. Instead, it acts as a living dictionary of DDS field definitions, giving you a clean, readable example of each type you’ll encounter in legacy systems or when maintaining older applications.
This example highlights:
- How DDS defines character, numeric, graphic, and large object fields
- The differences between packed, zoned, binary, and floating‑point numeric formats
- How DDS handles date, time, and timestamp fields with different formats
- What BLOB, CLOB, DBCLOB, DATALINK, and ROWID fields look like in DDS
- How to read and understand the structure of a fully annotated DDS PF
- Why these field types still matter when maintaining or modernizing IBM i applications
While modern IBM i development largely focuses on SQL, DDS is still deeply ingrained in countless production systems. Knowing DDS field types is key for maintaining legacy applications, converting DDS physical files to SQL DDL, troubleshooting data problems, reading and refactoring older RPG code, and understanding how IBM i stored data long before SQL became standard.
What You’re Looking At
With clear section headers, inline comments, and coverage of every major DDS field type, this guide includes realistic examples of lengths, precisions, and formats, plus a simple key field at the end. It’s the perfect “reference PF” to keep in your toolbox as you continue learning.
* Physical File: ALLFILE
* Description: Comprehensive example of all DDS field data types
* Author: Nick Litten
* Date: 2026-04-03
*=====================================================================
A R ALLREC TEXT('All Field Types Record')
*
*---------------------------------------------------------------------
* CHARACTER FIELDS
*---------------------------------------------------------------------
A CHARFLD 10A TEXT('Character field 10 bytes')
A CHARVAR 50A VARLEN TEXT('Variable length char')
A CHARFIX 1A TEXT('Single character field')
*
*---------------------------------------------------------------------
* NUMERIC FIELDS - PACKED DECIMAL
*---------------------------------------------------------------------
A PACKFLD 7P 2 TEXT('Packed decimal 7,2')
A PACKINT 9P 0 TEXT('Packed integer 9,0')
A PACKSMALL 3P 0 TEXT('Small packed 3,0')
A PACKLARGE 15P 5 TEXT('Large packed 15,5')
*
*---------------------------------------------------------------------
* NUMERIC FIELDS - ZONED DECIMAL
*---------------------------------------------------------------------
A ZONEDFLD 7S 2 TEXT('Zoned decimal 7,2')
A ZONEDINT 5S 0 TEXT('Zoned integer 5,0')
A ZONEDLRG 11S 3 TEXT('Large zoned 11,3')
*
*---------------------------------------------------------------------
* NUMERIC FIELDS - BINARY
*---------------------------------------------------------------------
A BINFLD2 4B 0 TEXT('2-byte binary integer')
A BINFLD4 9B 0 TEXT('4-byte binary integer')
A BINFLD8 18B 0 TEXT('8-byte binary integer')
*
*---------------------------------------------------------------------
* NUMERIC FIELDS - FLOATING POINT
*---------------------------------------------------------------------
A FLOATSGL 4F TEXT('Single precision float')
A FLOATDBL 8F TEXT('Double precision float')
*
*---------------------------------------------------------------------
* DATE/TIME/TIMESTAMP FIELDS
*---------------------------------------------------------------------
A DATEFLD L DATFMT(*ISO) TEXT('Date field ISO')
A DATEUSA L DATFMT(*USA) TEXT('Date field USA')
A DATEEUR L DATFMT(*EUR) TEXT('Date field EUR')
A DATEJIS L DATFMT(*JIS) TEXT('Date field JIS')
A DATEYMD L DATFMT(*YMD) TEXT('Date field YMD')
A DATEMDY L DATFMT(*MDY) TEXT('Date field MDY')
A DATEDMY L DATFMT(*DMY) TEXT('Date field DMY')
A DATEJUL L DATFMT(*JUL) TEXT('Date field JUL')
*
A TIMEFLD T TIMFMT(*ISO) TEXT('Time field ISO')
A TIMEHMS T TIMFMT(*HMS) TEXT('Time field HMS')
A TIMEUSA T TIMFMT(*USA) TEXT('Time field USA')
A TIMEEUR T TIMFMT(*EUR) TEXT('Time field EUR')
A TIMEJIS T TIMFMT(*JIS) TEXT('Time field JIS')
*
A TSTAMPFLD Z TEXT('Timestamp field')
*
*---------------------------------------------------------------------
* HEXADECIMAL FIELD
*---------------------------------------------------------------------
A HEXFLD 20A TEXT('Hex field 20 bytes')
*
*---------------------------------------------------------------------
* GRAPHIC FIELDS (DBCS - Double Byte Character Set)
*---------------------------------------------------------------------
A GRPHFLD 10G TEXT('Graphic field 10 chars')
A GRPHVAR 25G VARLEN TEXT('Variable graphic')
*
*---------------------------------------------------------------------
* LARGE OBJECT FIELDS
*---------------------------------------------------------------------
A BLOBFLD BLOB(1048576) TEXT('Binary large object')
A CLBFLD CLOB(524288) TEXT('Character large obj')
A DBLBFLD DBCLOB(262144) TEXT('DBCS large object')
*
*---------------------------------------------------------------------
* DATALINK FIELD
*---------------------------------------------------------------------
A DLINKFLD DATALINK(200) TEXT('DataLink field')
*
*---------------------------------------------------------------------
* ROWID FIELD
*---------------------------------------------------------------------
A ROWIDFLD ROWID TEXT('Row ID field')
*
*---------------------------------------------------------------------
* KEY FIELDS
*---------------------------------------------------------------------
A K CHARFLD