Oracle International Corporation

Sue-Kyoung Lee

Juan R Loaiza

Kothanda Umamageswaran

Sumanta Kumar Chatterjee

Margaret Susairaj

Alexander Tsukerman

Selcuk Aya

Kiran Badrinarain Goyal

Umesh Panchaksharaiah

Boris Erlikhman

Nilesh Choudhury

Bharat C V Baddepudi

Poojan Kumar

Timothy L Shetler

Susy Fan

Roshni Chatterjee

William Henry Benjamin Habeck

Preetham Solomon

Techniques are described herein for effectively managing usage of a shared object cache in a container database management system (DBMS). The shared object cache maintains shared objects belonging to a set of pluggable databases (PDBs) hosted by the container DBMS. In an embodiment, a shared object metadata extension structure (SOMEX) is maintained for each PDB. The SOMEX stores metadata for each shared object of the PDB that resides in the shared object cache. In an embodiment, a share of the shared object cache is maintained for shared objects from each PDB in the set of PDBs based on entries in the SOMEX for the PDB.

Efficient dual-objective cache

Techniques are provided for using an intermediate cache to provide some of the items involved in a scan operation, while other items involved in the scan operation are provided from primary storage. Techniques are also provided for determining whether to service an I/O request for an item with a copy of the item that resides in the intermediate cache based on factors such as a) an identity of the user for whom the I/O request was submitted, b) an identity of a service that submitted the I/O request, c) an indication of a consumer group to which the I/O request maps, d) whether the I/O request is associated with an offloaded filter provided by the database server to the storage system, or e) whether the intermediate cache is overloaded. Techniques are also provided for determining whether to store items in an intermediate cache in response to the items being retrieved, based on logical characteristics associated with the requests that retrieve the items.

Selectively reading data from cache and primary storage based on whether cache is overloaded

Automated management of shared I/O resources involves use of a policy engine for implementing I/O scheduling group I/O policies. The I/O policies are used for determining whether corresponding I/O requests should be issued to a shared storage system immediately or should be delayed via corresponding policy-based queues. In the context of database systems, a database administrator can specify policies regarding how I/O resources should be used and the database system itself enforces the policies, rather than requiring the database administrator enforce the I/O usage of the database and of the individual users.

Management of shared storage I/O resources

Techniques are provided for using an intermediate cache to provide some of the items involved in a scan operation, while other items involved in the scan operation are provided from primary storage. Techniques are also provided for determining whether to service an I/O request for an item with a copy of the item that resides in the intermediate cache based on factors such as a) an identity of the user for whom the I/O request was submitted, b) an identity of a service that submitted the I/O request, c) an indication of a consumer group to which the I/O request maps, or d) whether the intermediate cache is overloaded. Techniques are also provided for determining whether to store items in an intermediate cache in response to the items being retrieved, based on logical characteristics associated with the requests that retrieve the items.

Selectively reading data from cache and primary storage

Growing community of inventors

Foster City, CA, United States of America

Sue-Kyoung Lee