Read Mostly Instances

摘要

According to one aspect of the invention, a read-write instance of a multiple-instance database system receives a database statement for execution. The multiple-instance database system comprises a database shared by a plurality read-mostly instances that request only read access to a plurality of user database objects in the database and a plurality of read-write instances that request both read access and write access to the plurality of user database objects. The read-write instance selects one or more read-mostly instances, in the plurality of read-mostly instances, to perform one or more operations that require no write access to the plurality of user data objects.

主权项

1. A multi-instance database system comprising:
a database storing a plurality of user data objects; a plurality of instances configured to perform database operations on one or more of the plurality of user data objects; wherein the plurality of instances comprises a plurality of read-write instances configured with read access and write access to the plurality of user data objects; wherein the plurality of instances comprises a plurality of read-mostly instances configured with only read access to the plurality of user data objects; and a read-write instance configured to select one or more read-mostly instances, in the plurality of read-mostly instances, to perform one or more operations that require no write access to the plurality of user data objects.