Database Systems Each branch of the Jaja restaurant has a mainstay menu that is very popular with customers, so information on the availability of the number of servings is needed to be able to serve orders. Here are two transactions that are ordering a food menu at the same time. T1: Start the transaction at time t1, read 10 servings of food stock at t2. Because ordering one portion, the stock is reduced by 1 at t3. On t6, update the stock count, and commit to t7. T2: Transaction T2 starts a transaction on t2, reads the number of stocks in t3 as many as 10. At t4 orders 3 portions. On t5 it updates the stock to 7 and then on t6 commits it. As a result of the T1 and T2 transactions above, there was an error in the amount of food stocks. Make a solution with 2PL. What kinds of problems happened? Give a reason why choosing this type of problem! How much food is still available?
Each branch of the Jaja restaurant has a mainstay menu that is very popular with customers, so information on the availability of the number of servings is needed to be able to serve orders. Here are two transactions that are ordering a food menu at the same time.
T1: Start the transaction at time t1, read 10 servings of food stock at t2. Because ordering one portion, the stock is reduced by 1 at t3. On t6, update the stock count, and commit to t7.
T2: Transaction T2 starts a transaction on t2, reads the number of stocks in t3 as many as 10. At t4 orders 3 portions. On t5 it updates the stock to 7 and then on t6 commits it.
As a result of the T1 and T2 transactions above, there was an error in the amount of food stocks. Make a solution with 2PL. What kinds of problems happened? Give a reason why choosing this type of problem! How much food is still available?
Step by step
Solved in 2 steps with 1 images
