DataFlex Specifications
See Also: File Names & Extension Types, Logical Structure of a Database File, DataFlex Data Types, Database Essentials
Features
- DataFlex Studio - advanced Integrated Development Environment, with many built-in classes and completely customizable components and subclasses.
- Studio Code Explorer makes navigating, editing, and debugging programming code a breeze.
- Integrated source-level debugger to help track down and fix problems.
- Studio wizards for building numerous programming components, including applications, views, importing ActiveX controls, and consuming web services.
- Database Explorer for advanced raw table data viewing and editing.
- Object-Oriented 4th generation programming language (4GL).
- Data Access Connectivity Kits for accessing different databases (e.g., ODBC-compliant databases, Microsoft SQL Server, IBM DB2, and Pervasive.SQL) from DataFlex (automatically installed with DataFlex).
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 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
| Specification | Value |
|---|---|
| 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
| Specification | Value |
|---|---|
| Maximum indexes per table | 15 |
| Maximum segments per index | 16 |
| Maximum index key length | 256 Bytes |
Embedded (DataFlex) Database Column Specifications
| Specification | Value |
|---|---|
| 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.