CLEAR - Oracle SQL*Plus: The Definitive Guide [Book]
CLEAR The CLEAR command allows you to easily delete all column definitions, break settings, compute definitions, and so forth: CL[EAR] {BRE[AKS]|BUFF[ER]|COL[UMNS]|COMP[UTES]|SCR[EEN]|SQL|TIMI[NG]} where: CL[EAR