Question

Suppose a database schedule S which involves transactions T1, T2, ........, Tn. Consider the precedence graph of S with vertices representing the transactions and edges representing the conflicts. If S is serializable, which one of the following orderings of the vertices of the precedence graph is guaranteed to yield a serial schedule?

• A. Ascending order of transaction indices
• B. Breadth-First order
• C. Topological order
• D. Depth-First order

Answer 1

The correct option is C Topological order

For a schedule, we can check its serializability by drawing a precedence graph and find its topological order, precedence graph of schedule must not contain any cycle to be conflict free.