Final answer:
The Temporary Update or Dirty Read problem in databases occurs when data updated by one transaction is read by another before the update is committed, potentially leading to inconsistent data if the update is rolled back.
Step-by-step explanation:
The Temporary Update or Dirty Read problem refers to a situation in database systems where a transaction reads data that has been updated by another ongoing transaction but not yet committed. This means that if the update is not finalized, or if it is rolled back, the other transaction has read an incorrect, 'dirty' value. The correct statement to complete the sentence would be: The updated item is accessed by another transaction before it is changed back to its original state.
Explanation of the Dirty Read Problem
Consider two transactions, Transaction A and Transaction B. Transaction A updates a record but before it commits or rolls back the transaction, Transaction B reads the updated record. If for some reason Transaction A is rolled back after Transaction B has read the 'dirty' data, this can lead to inconsistent data or erroneous computations in the database, as Transaction B has acted on information that wasn't permanent or accurate. To avoid such situations, database management systems use isolation levels that can be set to prevent dirty reads.