Abstract: Fast purging of change data from a named change data database table by: (1) partitioning the table into partitions to separate data to be retained from data to be dropped and dropping the partition holding the data to be purged; or (2) creating a temporary change data database table and inserting the change data to be retained into a temporary table, dropping the named change data table, renaming the temporary table as the named table and inserting the change data within the temporary table into the renamed change table; or (3) creating a temporary change data table and copying data above a given value from the named table into the temporary database table, truncating the named table and inserting the data from the temporary into the named table and dropping the temporary table.

Abstract: In a PECVD process, the plasma potential is controlled and maintained at a uniform level to confine the formed plasma to the gap area between the electrodes away from the influence of the walls of the discharge chamber. The plasma potential is controlled by operating the system at a high pressure, above about 12 Torr, and monitoring the operation by observing the DC bias on the upper or driven electrode until a positive potential, preferably greater than about 10V, is developed. At this point a symmetrical glow discharge and a controlled plasma exists between the driven electrode and the susceptor electrode, controllable by maintaining the pressure between about 14 and 20 Torr, to reduce plasma damage to the semiconductor body being coated which maximizes yield.