60 lines
1.2 KiB
SQL
60 lines
1.2 KiB
SQL
-- CS 457/657 PA4
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-- This script includes the commands to be executed by two processes, P1 and P2
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-- On P1:
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CREATE DATABASE CS457_PA4;
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USE CS457_PA4;
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create table Flights (seat int, status int);
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insert into Flights values (22,0); -- seat 22 is available
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insert into Flights values (23,1); -- seat 23 is occupied
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begin transaction;
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update Flights set status = 1 where seat = 22;
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-- On P2:
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USE CS457_PA4;
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select * from Flights;
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begin transaction;
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update Flights set status = 1 where seat = 22;
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commit; --there should be nothing to commit; it's an "abort"
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select * from Flights;
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-- On P1:
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commit; --persist the change to disk
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select * from Flights;
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-- On P2:
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select * from Flights;
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---------------------
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-- Expected output --
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---------------------
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-- On P1:
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-- Database CS457_PA4 created.
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-- Using database CS457_PA4.
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-- Table Flights created.
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-- 1 new record inserted.
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-- 1 new record inserted.
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-- Transaction starts.
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-- 1 record modified.
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-- Transaction committed.
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-- seat int|status int
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-- 22|1
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-- 23|1
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-- On P2:
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-- Using database CS457_PA4.
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-- seat int|status int
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-- 22|0
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-- 23|1
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-- Transaction starts.
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-- Error: Table Flights is locked!
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-- Transaction abort.
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-- seat int|status int
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-- 22|0
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-- 23|1
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-- seat int|status int
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-- 22|1
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-- 23|1 |