Kbase P94561: Is the Transaction Number in the output of AIMAGE SCAN VERBOSE unique?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/16/2008 |
|
Status: Unverified
GOAL:
Is the Transaction Number in the output of AIMAGE SCAN VERBOSE unique?
GOAL:
What is the difference between the Transaction Number and Transaction Index?
FIX:
The transaction number (also known as the transaction ID) is the identifier of the transaction. It is an integer that rolls over eventually. The next transaction number is derived from the value stored in the database master block.
So in theory, there MAY be a case where the transaction number is not unique, however this is highly unlikely and has not been seen to occur in many instances, if any at all.
The transaction number and the transaction index are two separate things.
The transaction index is the in-memory transaction table's entry index for a given transaction, NOT the transaction number. It is unique at a given instant in time, as only one transaction's state can be described in a single transaction table entry.
Once the transaction ends, the transaction table entry will be reused for another transaction with a different transaction number, which will then have the same transaction index assigned to it.