| Patent application number | Description | Published |
|---|
| 20080306990 | SYSTEM FOR PERFORMING A REDISTRIBUTE TRANSPARENTLY IN A MULTI-NODE SYSTEM - Performing a redistribute of data in a database system including a plurality of nodes is disclosed. The data includes a plurality of partitions distributed between the plurality of nodes. At least one new node is being added. At least one partition of the plurality of partitions is selected to be moved from the plurality of nodes only to the at least one new node. The at least one partition is moved only to the at least one new node. At least one partition is removed from the plurality of nodes. | 12-11-2008 |
| 20110131192 | Approaches to Reducing Lock Communications In a Shared Disk Database - Lock communications in a shared disk database system is reduced by several approaches: sending a single message to a lock manager for locks required for an operation and locks that will be required in the future, the operations may include row update, row delete, large scan, and row insert; performing an operation in two executions, where in a first execution locks required for the operation is determined without performing the operation, and in a second execution a single message is sent to a lock manager for the required locks and the operation is performed; in free space searching, sending a single message to a lock manager for row and page locks before a row insert is actually performed; and granting locks in an unfair manner. | 06-02-2011 |
| 20110137861 | Methods for Achieving Efficient Coherent Access to Data in a Cluster of Data Processing Computing Nodes - A coherency manager provides coherent access to shared data by receiving a copy of updated database data from a host computer through RDMA, the copy including updates to a given database data; storing the copy of the updated database data as a valid copy of the given database data in local memory; invalidating local copies of the given database data on other host computers through RDMA; receiving acknowledgements from the other host computers through RDMA that the local copies of the given database data have been invalidated; and sending an acknowledgement of receipt of the copy of the updated database data to the host computer through RDMA. When the coherency manager receives a request for the valid copy of the given database data from a host computer through RDMA, it retrieves the valid copy of the given database data from the local memory and returns the valid copy through RDMA. | 06-09-2011 |
| 20110137874 | Methods to Minimize Communication in a Cluster Database System - An ordering of operations in log records includes: performing update operations on a shared database object by a node; writing log records for the update operations into a local buffer by the node, the log records each including a local virtual timestamp; determining that a log flush to write the log records in the local buffer to a persistent storage is to be performed; in response, sending a request from the node to a log flush sequence server for a log flush sequence number; receiving the log flush sequence number by the node; inserting the log flush sequence number into the log records in the local buffer; and performing the log flush to write the log records in the local buffer to the persistent storage, where the log records written to the persistent storage comprises the local virtual timestamps and the log flush sequence number. | 06-09-2011 |
