Readable physical storage replica and standby database system

A computer-implemented method, comprising:

• a standby database system replicating changes made to data blocks at a source database system to replicas of said data blocks at said standby database system;
• and
• while replicating said changes to said data blocks:
• receiving queries issued to said standby database system;
• and
• computing said queries based on data read from said data blocks;
• wherein each of the above steps is performed by one or more computing devices.

A computer-implemented method, comprising:

• a standby database system applying redo records that record changes to data blocks at a primary database system to replicas of said data blocks at said standby database system;
• in response to applying all redo records for a particular logical time, advancing an established logical time for computing queries to at least said particular logical time;
• and
• while replicating said changes to said data blocks:
• receiving a query issued to said standby database system;
• and
• computing results for said query that are consistent with said established logical time based on data read from said data blocks;
• wherein each of the above steps is performed by one or more computing devices.