Oracle International Corporation

Yu Kin Ho

Wilson Wai Shun Chan

Dungara Ram Choudhary

Tak Fung Wang

Angelo Pruscino

Wilson Wai Chan

Tolga Yurek

John C Hsu

Andrew Stuart Ingham

Deepti Srivastava

Chandrajith Ramachandran Unnithan

Walter Battistella

Francisco Rafael Flores Michel

Norman Lee

A computer program product, system, and computer implemented method for fast reuse of locking data structures prior movement of entries to a cache free list. The approach disclosed herein enables management of lock management structures. Specifically, the approaches provided herein are directed towards use of lock management structures where items are managed using at least a recycle list. A recycle list and a resource list pair associated with the recycle list are controlled using a single latch, where there are any number of buckets that each include a recycle list and a resource list pair. In addition, in some embodiments, a free list is also maintained, whereas resource lists and recycle lists have a one-to-one relationship with each other, the free list has a one-to-many relationship with the buckets and lists therein.

Fast reuse of locking data structures prior to movement of entries to a cache free list

Techniques are provided for determining access affinity between services in a database cluster, and for placing workload of those services based, at least in part, on the access affinity. The techniques involve generating access records that indicate when sessions that are associated with each service operate on data blocks that were accessed by another session that is associated with another service. Access affinity information is generated based on the access records, where the access affinity information indicates access affinity (e.g. conflict scores) between each pair of services. The cluster then selects which node is to perform the work of a given session based on the access affinity information and the service associated with the session.

Methods and systems for conflict detection and mitigation between services in an autonomous database cloud environment

A method and apparatus are described for assigning mastership of nodes to data blocks. A method involves connecting each session of a plurality of sessions to a particular node of a cluster of nodes based on services associated with the plurality of sessions. Each session of the plurality of sessions is associated with a respective service of a plurality of services. The method also involves collecting service-based access statistics aggregated by service and ranges of data block addresses. Each range corresponds to one or more contiguous subrange of data block addresses. The method further involves assigning mastership of the nodes to the data blocks having addresses within said ranges of data block addresses based on services associated with the nodes and the service-based access statistics.

Method and systems for master establishment using service-based statistics

Techniques related to cache recovery for failed database instances are disclosed. A first database instance and a second database instance share a primary persistent storage and a secondary persistent storage. Each database instance stores, in volatile memory, a respective primary cache of a respective set of data stored on the primary persistent storage. Each database instance also stores, in volatile memory, a respective set of header data. Further, each database instance moves the respective set of data from the respective primary cache to a respective secondary cache on the secondary persistent storage. Still further, each database instance stores, on the secondary persistent storage, a respective set of persistent metadata. When the first database instance becomes inoperative, the second database instance retrieves, from the secondary persistent storage, persistent metadata corresponding to data stored in a secondary cache of the first database instance. Header data is generated based on the persistent metadata.

Cache recovery for failed database instances

Described herein are techniques for adaptively managing timers that are used in various layers of a node. In many cases, the number of timers that occur in the system is reduced by proactively and reactively adjusting values of the timers based on conditions affecting the system, thereby making such a system to perform significantly better and more resiliently than otherwise.

Adaptive cluster timer manager

Growing community of inventors

Fremont, CA, United States of America

Yu Kin Ho