Borland Paradox

Paradox is a relational database management system originally published by Ansa Software and later by Borland and Corel. It was popular in the DOS and Windows database market.

What You Can Upload

• .DB table files
• .MB memo/BLOB files
• .PX primary index files
• .XG0-.XGn secondary index files
• .VAL validity check files
• ZIP archive with complete file sets

What You Get Out

DataMeans extracts your data into multiple modern formats:

How to Export / Obtain Files

1. Locate your Paradox application's data directory
2. Copy all .DB table files
3. Include associated .MB memo files
4. Include .PX and .XG* index files
5. Create a ZIP with all files
6. Upload the ZIP to DataMeans

Supported Features

• Paradox versions 4.x through 11
• Memo field support (.MB files)
• BLOB field extraction (.MB files)
• Password-protected table support (password required)
• Validity checks handling
• Table relationship reconstruction

Known Limitations

• Password-protected tables require password during upload
• Some complex validity rules documented but not enforced

Overview

Borland Paradox was a popular relational database management system for DOS and Windows, known for its intuitive Query By Example (QBE) interface and powerful reporting capabilities. It used a proprietary file format with separate files for data, indexes, and memos. Paradox was widely used in business applications during the 1980s and 1990s, particularly in the DOS era; Borland sold the product to Corel in 1996, and the final major version shipped in 2003.

History and Background

• 1985: Ansa Software releases Paradox 1.0 for DOS, introducing the QBE interface.
• 1986: Paradox 2.0 adds multi-user support with automatic table and record locking on PC networks.
• 1987: Borland acquires Ansa Software in a stock swap worth $29 million.
• 1989: Paradox 3.0 for DOS released, bundling the PAL-based Personal Programmer.
• 1990: Paradox 3.5 released; the separate Paradox SQL Link product adds connectivity to SQL database servers.
• 1992: Paradox 4.0 for DOS, rewritten with the Borland C++ windowing toolkit, adds memo and binary BLOB fields.
• 1993: Paradox for Windows 1.0 ships in January, introducing the ObjectPAL programming language; Paradox for Windows 4.5 follows the same year.
• 1994: Paradox 5.0 for Windows released, adding long integer, time, timestamp, logical, autoincrement, and BCD field types.
• 1995: Borland releases Paradox 7, a 32-bit version for Windows 95 and Windows NT.
• 1996: Borland sells Paradox to Corel in October.
• 1997: Corel Paradox 8 released as part of Corel WordPerfect Suite 8.
• 2003: Paradox 11, the final major version, ships with WordPerfect Office 11 Professional.
• 2009: Paradox receives its last update, a hot fix issued with WordPerfect Office X4.

File Format Specifications

Primary Files:

• .db: Data table file with fixed-length records
• .px: Primary key index file
• .mb: Memo/BLOB storage for memo, binary, graphic, and OLE fields
• .val: Field validity checks and referential integrity definitions
• .tv: Table view settings

Index Files:

• .Xnn/.Ynn: Paired single-field secondary index files (nn = field number)
• .XGn/.YGn: Paired secondary index files for composite and case-insensitive indexes, numbered sequentially from 0
• Descending secondary indexes were added with format level 7

File Structure:

• Header block with table metadata (record size, record count, block size, file version)
• Fixed-length records stored in data blocks
• Primary index blocks organized as a multi-level tree for fast lookups
• Memo and BLOB values stored in the .mb file, referenced by 10-byte pointers in the record
• Block size: 1024-4096 bytes, selected per table (header code 1-4 multiplied by 1 KB)

Data Types and Structures

Database Structure:

• Tables as primary data containers
• Referential integrity and validity checks stored in .val files
• Optional password protection with table encryption
• Multi-user concurrency through table and record locking
• Saved queries and reports stored in separate files alongside tables

Version Differences

Compatibility Notes:

• Later versions read tables created at earlier format levels
• The Borland Database Engine (BDE) can create tables at level 3, 4, 5, or 7
• Field types introduced at level 5 require a level 5 or level 7 table
• Tables can be password-protected and encrypted
• Open-source libraries such as pxlib read all table versions from 3.0 onward

Technical References

• Wikipedia: Paradox (database)
• Paradox Table File Format Specifications (Randy Beck)
• pxlib: Library to Read and Write Paradox Databases
• DOS Days: Borland Paradox
• Corel Paradox (WordPerfect)

To learn how to use this format with DataMeans, see the User Guide.