Final answer:
An edge is created from Ti to Tj if one of the operations in Ti appears before a write operation in Tj.
Step-by-step explanation:
An edge is created from Ti to Tj if one of the operations in Ti appears before a write operation in Tj.
Testing for conflict serializability can be done using the serialization graph method. This method involves creating a graph where the transactions are represented as nodes and the edges represent conflict relationships between the transactions. In this case, an edge is created from Ti to Tj if one of the operations in Ti appears before a write operation in Tj.
For example, if in transaction Ti there is an operation that reads a variable and in transaction Tj there is an operation that writes to the same variable, then there is a conflict between Ti and Tj and an edge is created from Ti to Tj in the serialization graph.