Product Documentation

V9 Update Guide

Previous Topic

Next Topic

Default Extended Headers for Enhanced Feature Support

Extended headers provide support for a range of enhanced c-tree features including

  • HUGE files
  • Six-byte transaction numbers
  • Segmented files
  • Transaction dependent creates and deletes
  • Restorable deletes

This extended support is now enabled by default with FairCom DB for all newly created files, regardless of the function call to create the files. Previously, this mode was only enabled with calls from an Xtd8 specific function and defining the XCREblk structure.

The advantage of this new approach is that 6-byte transaction numbers are used by default, which avoids potential unexpected transaction number overflows, or in some cases, encountering error R6BT_ERR (745, 6BTRAN file required).

This feature can be disabled with the following keyword should this be necessary for backward compatibility:

COMPATIBILITY REVERT_TO_V6HDR

Standalone applications can disable this support by setting the cth6flg global variable to any non-zero value.

TOCIndex