Cascadeless Schedule (ACID)

acid

Definition

Cascadeless Schedule (ACID)

A schedule is cascadeless if for each pair of transactions $T_i$ and $T_j$, were $T_j$ reads data items written by $T_i$, the commit operations of $T_i$ appears before the read by $T_j$.

In extends the recoverable schedule by preventing reading uncommitted data in the first place.

$$\text{Cascadeless}\subset \text{Recoverable}\subset \text{Schedules}$$

Examples

Cascadeless Schedule Example

Time	$T_1$	$T_2$
1	write($A$)
2	commit
3		read($A$)
4		commit