Final answer:
In databases, a recoverable schedule requires transactions to commit only after all transactions from which they have read have committed. This prevents inconsistencies if a transaction needs to be rolled back, ensuring the database maintains ACID properties for transactional integrity.
Step-by-step explanation:
A schedule S is recoverable if no transaction T in S commits until all transactions T' that have written an item that T has read have committed. This concept is pertinent in the field of databases, specifically concerning transaction management and ensuring data integrity. In the context of database systems, a recoverable schedule ensures that if a transaction must be rolled back, the system can recover to a consistent state because transactions that depend on uncommitted changes are prevented from committing prematurely.
For instance, imagine a scenario where Transaction T1 modifies an item, and subsequently, Transaction T2 reads this item and makes further modifications. If T2 were to commit before T1, and later T1 fails and needs to be rolled back, there would be a dependency on an uncommitted or rolled-back transaction, leading to potential inconsistencies. Hence, a recoverable schedule dictates that T1 must commit before T2 can commit. This ensures that if any transaction fails after committing, only committed data is referenced, aiding in preserving ACID properties (Atomicity, Consistency, Isolation, Durability) which are crucial for transactional integrity