CLONING A PLUGGABLE DATABASE IN READ-WRITE MODE

摘要

Embodiments create a clone of a PDB while the PDB accepts write operations. While the PDB remains in read-write mode, the DBMS copies the data of the PDB and sends the data to a destination location. The DBMS performs data recovery on the PDB clone based on redo entries that record changes made to the source PDB while the DBMS copied the source PDB files. This data recovery makes all changes, to the PDB clone, that occurred to the source PDB during the copy operation. The redo information, on which the data recovery is based, is foreign to the PDB clone since the redo entries were recorded for a different PDB. In order to apply foreign redo information to perform recovery on the PDB clone, a DBMS managing the PDB clone maintains mapping information that maps PDB source reference information to corresponding information for the PDB clone.

主权项

1. A computer-executed method comprising:
receiving an instruction to clone, to a destination location, a particular pluggable database at a source location; in response to receiving the instruction:
determining an initial time stamp that marks a time occurring before any files in the particular pluggable database are copied in connection with the received instruction to clone;copying files, included in the particular pluggable database, to the destination location to produce a copy of the particular pluggable database at the destination location;determining a final time stamp that marks a time occurring after copying the files included in the particular pluggable database is complete;collecting, from information for the particular pluggable database at the source location, redo information that was recorded between times marked by the initial time stamp and the final time stamp;based, at least in part, on the redo information, performing recovery on the copy of the particular pluggable database; wherein at least one of the steps of copying, collecting, and performing recovery are performed, at least partially, while the particular pluggable database is in read-write mode; and wherein the method is performed by one or more computing devices.