DataFlex Specifications

See Also: File Names & Extension Types, Logical Structure of a Database File, DataFlex Data Types, Database Essentials  

 

Features

 

Requirements

Please refer to the Installation and Environment Guide to ascertain the requirements for memory, disk space, and operating system version that apply to your version of DataFlex.

Structure

Extended relational DBMS with data-independent utilities and command language.

Connectivity Kits

DataFlex supports access to numerous different database formats through Connectivity Kits. Connectivity Kits are available for IBM DB2, Microsoft SQL, Pervasive.SQL and ODBC connectivity. Data Access Connectivity Kits allow for seamless conversion to and from, as well as direct access to, various different database formats without recompilation of applications. With the exception of the ODBC, all Connectivity Kits are direct drivers from DataFlex, and thus allow direct and fast access to the database.

Database Specifications (All Databases used with DataFlex)

Maximum DBMS tables per filelist

4095

 

Embedded (DataFlex) Database Record & Table Specifications

Maximum data elements (columns) per table

255

Maximum characters in physical table name (root name)

40

Maximum characters in addressable table name (DataFlex name)

31 (only use up to 8 if compatibility with revisions prior to DataFlex 17.0)

Maximum table file size

2 Gigabytes (2,147,483,647 Bytes)

Maximum records per table

16.7 Million (16,700,000)

Maximum record size

16 Kilobytes (16,384 Bytes)

Data table type

Packed, fixed-length random access

Numeric storage formats

Packed BCD fixed point.
Floating point

Numeric precision

Fixed point: 8 places after decimal point.

Floating point: 16 significant digits.

DECIMAL type adds 16.16 support.

Numeric range

Fixed: ±9,999,999,999,999,999. 9999999999999999
with DECIMAL type.

Floating: ±1.0e±306

Reserved filelist numbers

50, 251-299

 

Embedded (DataFlex) Database Index Specifications

Maximum indexes per table

15

Maximum segments per index

16

Maximum index key length

256 Bytes

 

Embedded (DataFlex) Database Column Specifications

Maximum characters in column name

32 (only use up to 15 if compatibility with revisions prior to DataFlex 17.0)

Maximum data element (column) size

16 Kilobytes (16,384 Bytes)

Maximum size of ASCII column

255 characters

Maximum size of text column

16 Kilobytes (16,384 Bytes)

Size of date column

3 Bytes (Fixed)

Maximum size of numeric column

99,999,999,999,999.99999999 to -9,999,999,999,999.99999999 (14.8 places)

Maximum size of binary column

16 Kilobytes (16,384 Bytes)

 

Application / Coding

Specifications for DataFlex data types can be found in the Language Guide.

All of the below specifications are per application. Each DataFlex application can call other applications (including other DataFlex applications), and even return to the same place in the code after doing so using the runprogram command.

Maximum lines per program

128 million (128,000,000)

Maximum line length in Code Editor

4096 characters

Maximum compilable statement length

4095 characters (a statement exceeding 255 characters must be broken up into multiple lines of code, separated by a semicolon, which indicates a continuous statement).

Maximum custom error message length

2048 characters

Maximum number of devices that can be
simultaneously opened for sequential file I/O

10

Program file characteristics

Protected source, semi-compiled

Maximum number of objects

16,777,216

Maximum object messages

3,072

Maximum number of classes

64,869

Maximum size of compiled program without symbols

2 Gigabytes (2,147,483,647 Bytes)

Maximum data tables open concurrently

Memory limited only

 
 

DataFlex Identifiers

DataFlex identifiers must begin with a letter a-z or A-Z. This includes all identifiers in the language: variable names, class names, object names, table names, etc. (i.e. any name used in your program code).

DataFlex Program File

When a DataFlex application is compiled, a file with an .exe extension is created (e.g., MyApplication.exe).  To execute a DataFlex application, simply double-click on the .exe file in Windows Explorer.

 

See Also

General Reference