Solution

The correct answer is 2) B and C Only.

Key Points

• The phantom problem occurs in database systems when a transaction reads a set of rows that satisfy a condition, but another transaction inserts or deletes rows that would have satisfied the condition. This can lead to inconsistent results.
• Index Locking is a technique where locks are placed on the index entries that match the search condition. This prevents other transactions from inserting or deleting rows that would affect the result set.
• Predicate Locking involves locking the entire set of rows that satisfy a condition. This ensures that no new rows can be inserted or deleted that would affect the result set.

Additional Information

• Time Stamping is a concurrency control mechanism that assigns a unique timestamp to each transaction. It is not specifically designed to handle the phantom problem.
• Execution Indexing is not a standard term in database concurrency control and is not related to solving the phantom problem.