Conflicting Instructions
Generally, in concurrent execution, for the same data item, if the I/O operations belong to two different transactions such that the following combinations of instructions are adjacent from different transactions like
- Read, Write
- Write, Read
- Write, Write
Then, those two I/O operations are said to be ‘Conflicting Instructions’.
Example-1: Consider the following schedule-7.
T3 | T4 |
Read Q | |
Write Q | |
Write Q |
Here, (1,2) and (2,3) are pairs of conflicting instructions.
This schedule is NOT equivalent to either <T3, T4> or <T4, T3>.
So, this schedule-7 is not Conflict Serializable.
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