Numero de campos
Hola, por favor necesito saber cual es el numero de campos maximo que acepta Visual foxpro 6.0. Tengo un formato bastante grande con 593 campos. He pensado en 3 tablas...pero no tengo experiencia en manejo de base de datos. Agradecere cualquier sugerencia.
Gracias
Maria
Gracias
Maria
1 Respuesta
Respuesta de nercules
1
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
-> 10 bits per exponent + 1 for exponent sign plus 1 for number sign => 12 bits
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.
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
-> 10 bits per exponent + 1 for exponent sign plus 1 for number sign => 12 bits
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.
