On the top of the graphic, pdb1_prod is crossed out. The label says “Logical Corruption in P.M. on Mon 4/9.” The PDB points right and is labeled “Create Snapshots.” The arrow points to a circle of PDBs, each labeled with a different date: Mon 4/2, Tue 4/3, Wed 4/4, Thu 4/5, Fri 4/6, Sat 4/7, Sun 4/8, and Mon 4/9.
On the bottom of the graphic, pdb1_prod is on the left, and is pointed to by a snapshot PDB labeled Mon 4/9. The arrow is labeled “CREATE ... USING SNAPSHOT.”