NAME
sqlite3_snapshot_cmp —
Compare the ages
of two snapshot handles.
SYNOPSIS
int
sqlite3_snapshot_cmp(
sqlite3_snapshot
*p1,
sqlite3_snapshot *p2 );
DESCRIPTION
The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages of two
valid snapshot handles.
If the two snapshot handles are not associated with the same database file, the
result of the comparison is undefined.
Additionally, the result of the comparison is only valid if both of the snapshot
handles were obtained by calling sqlite3_snapshot_get() since the last time
the wal file was deleted. The wal file is deleted when the database is changed
back to rollback mode or when the number of database clients drops to zero. If
either snapshot handle was obtained before the wal file was last deleted, the
value returned by this function is undefined.
Otherwise, this API returns a negative value if P1 refers to an older snapshot
than P2, zero if the two handles refer to the same database snapshot, and a
positive value if P1 is a newer snapshot than P2.