Recovery:

Considering the following database schedule with two transactions, T$1$ and T$2.$

$S=r2(x)$;$r1(x)$;$r2(Y)$; w$1($X$)$; r$1($Y$)$; w$2($X$)$; a$1$; a$2$;

where $ri(Z)$ denotes a read operation by transaction Ti on a variable $Z,$ wi $(Z)$ denotes a write operation

by $Ti$ on a variable $Z$ and ai denotes an abort by transaction $Ti.$

Check whether $S$ is recoverable and$/$or cascade less schedule.