Several years ago, an IBMer was on a mission to raise or eliminate many of the upper limits in OS/400--for example, to increase the maximum length of an index for a file from 120 bytes to the 2000 bytes we have today.
Recently, while teaching at a client's office, I was asked about database limits. What's the maximum width of a database record? What is the maximum number of records in a file? And so forth. So I put together a little table of maximums for database. The original source for these figures is, like everything, in the various IBM manuals as well as the InfoCenter at IBM.
| Database Item | Limit |
| Fields in a record format | 8,000 |
| Bytes in a record format | 32,766 |
| Bytes in a database file | 1 TB |
| Fields that make up an index entry | 120 |
| Bytes in an index entry | 2,000 |
| Bytes in an entire index | 1 TB |
| Records in a file | 4 GB |
| Indexes over a physical file member | 4000 |
| Members that may be joined (using DDS) | 32 |
| Members that may be joined (using SQL) | 256 |
| Records locked for a commitment control transaction | About 500,000,000 |
| Triggers on a file | 300 |
| Members in a file | 32,767 |
| Files that may be used at one time | 500,000 |
| Length of a character field in database | 32,765 |
| 8-byte INT (20I0 in RPG) | From: -922,337,2036,854,775,808 To: +922,337,2036,854,775,807 |
| 4-byte INT (10I0 in RPG) | From: -2,147,483,648 To: +2,147,483,647 |
| 2-byte INT (5I0 in RPG) | From: -32,768 To: +32,767 |
| 1-byte INT (3I0 in RPG) | From: -256 to +255 |
| Length of a packed/zoned decimal value | V5R2: 31 V5R3: 63 |
| Objects in a library | 360,000 |
| Files that can be open at one time by the file server | 16,776,960 |
| Bytes for a Domino database | 256 GB |
| Records in a version of the history log | 65,535 |
| Input fields on a display file at one time | 256 |
Bob Cozzi has been programming in RPG since 1978. Since then, he has written many articles and several books, including The Modern RPG Language--the most widely used RPG reference manual in the world. Bob is also a very popular speaker at industry events such as RPG World and is the author of his own Web site and of the RPG ToolKit, an add-on library for RPG IV programmers.
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