摘要:
A method and apparatus for efficiently managing cached objects is provided. A mapping is a typed relationship between cached objects. A base object contains content, and a mapped object is mapped to a base object when there is a particular relationship between the mapped object and the base object. The type of mapping defines how the objects in the relationship are treated when the mapped object is created, read, or written. At creation time, the mapping type may define how the mapping relationship is recognized. Sometimes recognizing a relationship requires establishing equivalence between the objects. At read and write time, the mapping type may define on which object a mutual exclusion lock is held, which content is returned or which object's content is updated. A wide range of applications can benefit from enhanced object caching performance, and in addition, application may define application-specific semantics on mapping types as well.
摘要:
Disclosed are improved methods, systems, and media for cursor sharing and cursor pruning. According to some approaches, existing child cursors are distinguished using a cursor sharing criteria node structure. A sharing criteria node (also referred to as a “diagnostic” node) is created when a sharing criteria mismatch/failure happens. The node contains information about why the child cursor could not be shared and also information that can be used to quickly re-evaluate this sharing criterion in the future.
摘要:
A method and apparatus for efficiently managing cached objects is provided. A mapping is a typed relationship between cached objects. A base object contains content, and a mapped object is mapped to a base object when there is a particular relationship between the mapped object and the base object. The type of mapping defines how the objects in the relationship are treated when the mapped object is created, read, or written. At creation time, the mapping type may define how the mapping relationship is recognized. Sometimes recognizing a relationship requires establishing equivalence between the objects. At read and write time, the mapping type may define on which object a mutual exclusion lock is held, which content is returned or which object's content is updated. A wide range of applications can benefit from enhanced object caching performance, and in addition, application may define application-specific semantics on mapping types as well.
摘要:
A database may facilitate zero-downtime upgrades by concurrently maintaining multiple editions of database objects for use by both pre-upgrade and post-upgrade clients of a database application. Operations performed within the database are associated with an edition based on, for example, an initiating client or transaction. When an operation references an object or data, the database automatically performs the operation using the object or data associated with the edition with which the operation is itself associated. The database may determine the associated edition without explicit identification of the associated edition in a query or in code. Thus, no client or stored procedure code changes are necessary to reflect a new edition added during an update. Data changes in one edition may be automatically and immediately propagated to the other edition through the use of cross-edition triggers, thereby allowing both pre-upgrade and post-upgrade clients to remain fully functional throughout an upgrade.
摘要:
A database may facilitate zero-downtime upgrades by concurrently maintaining multiple editions of database objects for use by both pre-upgrade and post-upgrade clients of a database application. Operations performed within the database are associated with an edition based on, for example, an initiating client or transaction. When an operation references an object or data, the database automatically performs the operation using the object or data associated with the edition with which the operation is itself associated. The database may determine the associated edition without explicit identification of the associated edition in a query or in code. Thus, no client or stored procedure code changes are necessary to reflect a new edition added during an update. Data changes in one edition may be automatically and immediately propagated to the other edition through the use of cross-edition triggers, thereby allowing both pre-upgrade and post-upgrade clients to remain fully functional throughout an upgrade.