US 7,689,549 B2 · Flashback support for domain index queries

Abstract

Techniques for executing flashback queries using domain indexes in a database system are provided. In one technique, a flashback parameter of the flashback query is not included in a call-out invocation of domain index routines that implement a domain index. A call-back query execution unit nonetheless retrieves, for call-back queries issued by the domain index routines, call-back query results that reflect the state of a database in the database system as of the time specified in the flashback parameter. In another technique, a call-out invocation of domain index routines includes the flashback parameter of a flashback query. The domain index routines issue call-back queries that require the retrieval of data which reflects the state of a database as of the time specified in the flashback parameter, which are executed by the call-back query execution unit.

Claims14

Dependent claims

A method of processing a flashback query to return data from a prior target logical state of a database system, the method comprising the steps of:

receiving, at said database system, said flashback query, wherein a response to the flashback query requires said database system to retrieve said data from said prior target logical state of said database system, where the prior target logical state corresponds to a target time;
and
in response to receiving said flashback query, computing said flashback query using an index structure that is not natively supported by said database system to retrieve said data, wherein said data that is retrieved using said index structure accurately reflects said prior target logical state of said database system, but does not reflect a different logical state of said database system that exists after said target logical state;
wherein the method is performed by one or more computing devices.

1 more element

A computer-readable storage medium carrying one or more sequences of instructions for processing a flashback query to return data from a prior target logical state of a database system, which instructions, when executed by one or more processors, causes the one or more processors to perform:

receiving, at said database system, said flashback query, wherein a response to the flashback query requires said database system to retrieve said data from said prior target logical state of said database system, where the prior target logical state corresponds to a target time;
and
in response to receiving said flashback query, computing said flashback query using an index structure that is not natively supported by said database system to retrieve said data, wherein said data that is retrieved using said index structure accurately reflects said prior target logical state of said database system, but does not reflect a different logical state of said database system that exists after said target logical state.

Dependencies are inferred from the claim text.

Flashback support for domain index queries

Life of this patent

Flashback support for domain index queries

Life of this patent

Abstract

Claims14