Minimizing data volume growth under encryption changes

A method for minimizing data volume growth of a data volume in a database system under changes to an encryption status of a plurality of data pages associated with one or more databases in the database system, the method comprising:

• receiving a request to update an encryption parameter associated with the one or more databases;
• selectively iterating metadata associated with the plurality of pages to determine that a candidate page requires encryption changes in connection with the request to update the encryption parameter;
• in response to determining that the candidate page is not currently in use by one or more active database snapshots:
• in response to determining that the candidate page is not currently loaded in main memory loading the candidate page into main memory;
• performing an encryption operation on the candidate page based on the updated encryption parameter to render an encrypted page;
• and
• designating the encrypted page for persistence;
• based on a current number of candidate pages already encrypted during a current save point cycle, pausing the selective iteration until a subsequent save point cycle;
• and
• for each candidate page in the selective iteration:
• determining, based on a size of the candidate page, the candidate page to be copied to a superblock page;
• in response to determining the size of the candidate page is below a threshold, copying the candidate page into the superblock page;
• generating a control superblock associated with the candidate page, wherein the control superblock includes the encryption parameter;
• performing the encryption operation for each candidate page of the superblock page based on the encryption parameter within the control superblock;
• and
• flushing the superblock page to disk storage.

A system for minimizing data volume growth of a data volume in a database system under changes to an encryption status of a plurality of data pages associated with one or more databases in the database system, the system comprising at least one processor and at least one non-transitory memory storing computer executable instructions that when executed by the processor cause the system to carry out actions comprising:

• receiving a request to update an encryption parameter associated with the one or more databases;
• selectively iterating metadata associated with the plurality of pages to determine that a candidate page requires encryption changes in connection with the request to update the encryption parameter;
• in response to determining that the candidate page is not currently in use by one or more active database snapshots:
• in response to determining that the candidate page is not currently loaded in main memory, loading the candidate page into main memory;
• performing an encryption operation on the candidate page based on the updated encryption parameter to render an encrypted page;
• and
• designating the encrypted page for persistence;
• based on a current number of candidate pages already encrypted during a current save point cycle, pausing the selective iteration until a subsequent save point cycle;
• and
• for each candidate page in the selective iteration:
• determining, based on a size of the candidate page, the candidate page to be copied to a superblock page;
• in response to determining the size of the candidate page is below a threshold, copying the candidate page into the superblock page;
• generating a control superblock associated with the candidate page, wherein the control superblock includes the encryption parameter;
• performing the encryption operation for each candidate page of the superblock page based on the encryption parameter within the control superblock;
• and
• flushing the superblock page to disk storage.