Visual FoxPro System Capacities
Some capacities may be limited by available memory.
| Category | Feature | Capacity |
|---|
Table and Index Files
| Maximum # of records per table file | 1 billion | |
| Maximum size of a table file | 2 gigabytes | |
| Maximum size of an FPT file | 2 gigabytes | |
| Maximum # of characters per record | 65,500 | |
| Maximum # of fields per record1 | 255 | |
| Maximum # of tables open at one time2 | 65,535 | |
| Maximum # of characters per table field | 254 | |
| Maximum # of bytes per index key in a non-compact index3 | 100 | |
| Maximum # of bytes per index key in a compact index3 | 240 | |
| Maximum # of open index files per table2 | Unlimited | |
| Maximum # of open indexes in all work areas2 | Unlimited | |
| Maximum # of relations | Unlimited | |
| Maximum length of relational expressions | Unlimited |
Field Characteristics
| Maximum size of character fields | 254 | |
| Maximum size of numeric and float fields | 20 | |
| Maximum number of characters in field names in a free table | 10 | |
| Maximum number of characters in field names for a table contained in a database | 128 | |
| Minimum value of an integer | -2,147,483,647 | |
| Maximum value of an integer | 2,147,483,647 | |
| Digits of precision in numeric computations. Visual FoxPro can handle numbers up to 9007199254740992 (2^53) in exact computations. | 16 | |
Miscellaenous:
64 bits = 8 bytes Largest number = 10 ^ 308 = 2 ^ 1023 Leaving 52 bits for the mantissa + 1 for implied normalized bit -> 53 bits LOG10(2^53) = 15.95 decimal digits accuracy |
Variables and Arrays
| Default # of variables | 1,024 | |
| Maximum # of variables | 65,000 | |
| Maximum # of arrays | 65,000 | |
| Maximum # of elements per array | 65,000 |
Program and Procedure Files
| Maximum # of lines in source program files | Unlimited | |
| Maximum size of compiled program modules4 |
64K | |
| Maximum # of procedures per file | Unlimited | |
| Maximum # of nested DO calls | 128 | |
| Maximum # of READ nesting levels | 5 | |
| Maximum # of nested structured programming commands | 384 | |
| Maximum # of passed parameters | 26 | |
| Maximum # of transactions | 5 |
Report Designer Capacities
| Maximum # of objects in a report definition2 | Unlimited | |
| Maximum length of a report definition | 20 inches | |
| Maximum # of grouping levels | 128 | |
| Maximum length of character report variables | 255 |
Other Capacities
| Maximum # of open windows (all types)2 | Unlimited | |
| Maximum # of open Browse windows | 255 | |
| Maximum # of characters per character string or memory variable | 16,777,184 | |
| Maximum # of characters per command line | 8,192 | |
| Maximum # of characters per label control on a report | 252 | |
| Maximum # of characters per macro substituted line | 8,192 | |
| Maximum # of open files | System limit | |
| Maximum keystrokes in keyboard macro | 1,024 | |
| Maximum fields that can be selected by a SQL SELECT statement | 255 | |
| Maximum length of a string literal | 255 | |
| Maximum # of pages in a report at runtime | 32767 |
1 If one or more fields allow null values, the limit is reduced by one to 254 fields.
2 Limited by memory and available file handles. .cdx files use only one file handle.
3 If the collating sequence is set to MACHINE, each character uses one byte. If the collating sequence is not set to MACHINE, each character uses two bytes. If the indexed field supports null values, one additional byte is used in the index key. Note that non-machine indexes are always compact.
4 A program module is one procedure. A program or application can contain an unlimited number of program modules.
See Also
Table File Structure (.dbc, .dbf, .frx, .lbx, .mnx, .pjx, .scx, .vcx) | Setting Up an ODBC Data Source | Display System Information | Optimizing Your System | File Extensions and File Types | Optimizing Visual FoxPro Startup Speed | Special Terms for Configuration Files