A computer system comprising: one or more processors (312, 314, 316, 322, 545, 550); a primary database system (405a, 505. 605, 705, 805, 904) implemented by the one or more processors (312, 314, 316, 322, 545, 550); and a secondary database system (405b, 510. 610, 710, 810, 906) implemented by the one or more processors (312, 314, 316, 322, 545, 550), the secondary database system (405b, 510. 610, 710, 810, 906) configured as a backup system for the primary database system (405a, 505. 605, 705, 805, 904) that is capable of providing at least a minimum amount of essential functionality of the primary database system required to restore the primary database system (405a, 505. 605, 705, 805, 904) during a disruption to the primary database system (405a, 505. 605, 705, 805, 904); wherein the primary database system (405a, 505. 605, 705, 805, 904) and secondary database system (405b, 510. 610, 710, 810, 906) differ in that all requests from a client application (145, 230, 634, 734, 834, 901) that require a write transaction are executed only in the primary database system (405a, 505. 605, 705, 805, 904), and that all write transactions to persistent objects are prohibited by the secondary database system (405b, 510. 610, 710, 810, 906); wherein the primary database system (405a, 505. 605, 705, 805, 904) is configured by programming instructions, executable on the computer system, to cause the one or more processors (312, 314, 316, 322, 545, 550) to: receive by the primary database system (405a, 505. 605, 705, 805, 904) a query request from a client application (145, 230, 634, 734, 834, 901) in advance of receiving a query, determine by the primary database system (405a, 505. 605, 705, 805, 904) from the query request from the client application (145, 230, 634, 734, 834, 901) directed to the primary database system (405a, 505. 605, 705, 805, 904) that a routing hint in the query request indicates that workload from the query may be shifted to the secondary database system (405b, 510. 610, 710, 810, 906), determine that execution of the query does not involve writing data, determine by the primary database system (405a, 505. 605, 705, 805, 904) to instruct the client application (145, 230, 634, 734, 834, 901) to route the query to the secondary database system (405b, 510. 610, 710, 810, 906), and instruct the client application (145, 230, 634, 734, 834, 901) to direct the secondary database system (405b, 510. 610, 710, 810, 906) to execute the query. one or more processors (312, 314, 316, 322, 545, 550); a primary database system (405a, 505. 605, 705, 805, 904) implemented by the one or more processors (312, 314, 316, 322, 545, 550); and a secondary database system (405b, 510. 610, 710, 810, 906) implemented by the one or more processors (312, 314, 316, 322, 545, 550), the secondary database system (405b, 510. 610, 710, 810, 906) configured as a backup system for the primary database system (405a, 505. 605, 705, 805, 904) that is capable of providing at least a minimum amount of essential functionality of the primary database system required to restore the primary database system (405a, 505. 605, 705, 805, 904) during a disruption to the primary database system (405a, 505. 605, 705, 805, 904); wherein the primary database system (405a, 505. 605, 705, 805, 904) and secondary database system (405b, 510. 610, 710, 810, 906) differ in that all requests from a client application (145, 230, 634, 734, 834, 901) that require a write transaction are executed only in the primary database system (405a, 505. 605, 705, 805, 904), and that all write transactions to persistent objects are prohibited by the secondary database system (405b, 510. 610, 710, 810, 906); wherein the primary database system (405a, 505. 605, 705, 805, 904) is configured by programming instructions, executable on the computer system, to cause the one or more processors (312, 314, 316, 322, 545, 550) to: receive by the primary database system (405a, 505. 605, 705, 805, 904) a query request from a client application (145, 230, 634, 734, 834, 901) in advance of receiving a query, determine by the primary database system (405a, 505. 605, 705, 805, 904) from the query request from the client application (145, 230, 634, 734, 834, 901) directed to the primary database system (405a, 505. 605, 705, 805, 904) that a routing hint in the query request indicates that workload from the query may be shifted to the secondary database system (405b, 510. 610, 710, 810, 906), determine that execution of the query does not involve writing data, determine by the primary database system (405a, 505. 605, 705, 805, 904) to instruct the client application (145, 230, 634, 734, 834, 901) to route the query to the secondary database system (405b, 510. 610, 710, 810, 906), and instruct the client application (145, 230, 634, 734, 834, 901) to direct the secondary database system (405b, 510. 610, 710, 810, 906) to execute the query.