GATE Overflow Test Series | Mixed Subjects | Test 3 | Question: 13

Question

If there are $n$ transactions each having $m_{1},m_{2},\dots,m_{n}$ operations respectively, the number of concurrent schedules possible is ______ (Mark all the appropriate options)

• A. $\dfrac{(m_{1} + m_{2} + m_{3} + \dots + m_{n})!}{m_{1}!m_{2}!m_{3}!\dots m_{n}!}$
• B. $n! - \dfrac{(m_{1} + m_{2} + m_{3} + \dots + m_{n})!}{m_{1}!m_{2}!m_{3}!\dots m_{n}!} $
• C. $^{m_1+m_2+m_3+...+m_n}C_{m_1}\times^{m_2+m_3+\ldots+m_n}C_{m_2}\times^{m_3+\ldots+m_n}C_{m_3}\times \ldots \times^{m_n}C_{m_n}$
• D. $\dfrac{(m_{1} \times m_{2} \times m_{3} \times \dots \times m_{n})!}{m_{1}!m_{2}!m_{3}!\dots m_{n}!} $

Answer 1

The correct answer is $A;C.$

Comments

see here, https://cs.stackexchange.com/questions/19295/number-of-concurrent-schedules-in-database

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I think none of the options are correct, option A and C also includes serial schedules. for no of concurrent schedules we need to subtract n!, right??

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Concurrent Schedule include serial schedule .

Non serial Schedule does not include Serial schedule => in this case we have to do
No of Concurrent Schedule – No of Serial schedule