Description of tableBASE library versions

With the introduction of tableBASE Version 6 and Library Bridge, there are now a number of types of tableBASE libraries. The attributes of each are highlighted below:

Version 5 libraries

• Created with tableBASE Version 5 (including Library Bridge tableBASE 5.B)
• Can be converted to Bridge or Version 6 libraries
• Can be accessed by tableBASE Version 5.x and Library Bridge
• 3120 Block Size, Version 5 directory structure, indexes are stored on the library, hash tables may be true or indexed, paged tables supported

Bridge libraries

• Created only by converting a Version 5 library
• Convert from Version 5 libraries via the Library Bridge conversion utility
• Can be converted back to Version 5 libraries
• Can be converted to Version 6 libraries
• Can be accessed by Library Bridge, and tableBASE Version 6.0.2 (or later)
• 3120 Block Size, V6 directory structure, indexes are stored on the library, no paged tables
• Can NOT be accessed by any tableBASE 5.x releases prior to Release 5.B
• Can NOT be accessed by any tableBASE 6.0 releases prior to Release 6.0.2

Version 6 transition libraries

• Created originally by converting Version 5 tableBASE libraries using the job streams CVLB526B and CVLB526V delivered with tableBASE 6.0.1 that are now obsolete (see note below)
• Converted from Version 5 libraries using the conversion utility DK1TCNV
• Can be converted back to Version 5 libraries if they have not been expanded
• 3120 Block Size, Version 6 directory structure, indexes are stored on the library, no paged tables
• Can only be accessed by tableBASE release 6.0.x (or later)

Version 6 libraries

• Defined with tableBASE Version 6 or are converted from Version 5, Bridge, or Version 6 Transition libraries with the conversion utility DK1TCNV.
• Cannot be converted back to any other type of library
• Can only be accessed by tableBASE Version 6
• Have no fixed Block Size after conversion to Version 6 (this feature does not apply to libraries converted from previous library versions to the Version 6 format).
• Have Version 6 directory structure— no paged tables
• Provide better performance then Version 4 or Version 5 libraries:
  • Tables have dynamic indexes that are build at open time, instead of having to read indexes from and write indexes to the library.
  • Libraries that are dedicated to a region may cache their directory information, eliminating many library accesses.
  • Libraries can be defined with BLOCKSIZEs optimized for your table characteristics and DASD devices.