March 2003
Intermediate to advanced
912 pages
27h 17m
English
We defined a transaction as a (possibly composite) atomic operation that is meaningful to the application level: a transaction relates to some given level in an operation hierarchy. A transaction therefore causes the system to move from one consistent state at this level to another. If the possibility of crashes is ignored in the first instance, a consistent system state can be maintained by executing transactions serially.
If one process's transaction is executed to completion before any other can start there is no possibility of interference between them. We would then have made the transaction a single Part II-style indivisible operation (Figure 19.2). Such a procedure (single threading ...