Turboimage Database Enhancements - August 2001

Options for Runtime Control Block
• Copying DBUX and DBU
• Sharing DBUX and DBU
•Pros for Sharing
- The key concept for thread is sharing, so does DBU
- Share DBU will share open files
- Share DBU will share current record pointers
•Cons for Sharing
- Need mechanism to control the currency of XM and
locking in DBU
- Need space control procedures to handle DBU trailer
area
- Need extra space for log record belongs to different PIN
- Break the coherency among the DBOPEN, “accessor
entry” and DBU