摘要:
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.
摘要:
In a shared data system comprising one or more primary nodes and a plurality of secondary nodes, global lock manager on a primary node manages locks for shared resources by exchanging an abstract lock state with local lock managers on the secondary nodes. The abstract lock state includes a particular representation of all of the applications on the nodes that are requesting or are granted locks. The exchange of these particular lock states instead of individual requests improves performance by increasing concurrency and reducing off-machine communication. A global deadlock detector on a node detects and resolves global deadlocks, in conjunction with local deadlock detectors on the secondary nodes.
摘要:
In a shared data system comprising one or more primary nodes and a plurality of secondary nodes, global lock manager on a primary node manages locks for shared resources by exchanging an abstract lock state with local lock managers on the secondary nodes. The abstract lock state includes a particular representation of all of the applications on the nodes that are requesting or are granted locks. The exchange of these particular lock states instead of individual requests improves performance by increasing concurrency and reducing off-machine communication. A global deadlock detector on a node detects and resolves global deadlocks, in conjunction with local deadlock detectors on the secondary nodes.
摘要:
A method for updating and reading data stored in a static memory in a computer system is disclosed. An update queue stores one or more update records in dynamic memory that specify changes made by a transaction to data stored in the static memory. If a transaction requests data for which the transaction has previously generated an update record updated data is generated in dynamic memory, where the updated data reflecting the changes specified by the update records. The updated data is then supplied to the transaction.
摘要:
A method, system, and article are provided for employment of a hybrid layout of representation of data objects in computer memory. Columns of the database are separated based upon a classification of the columns. A vertical partition in the form of a bank is provided to receive an assignment of one or more data objects identified in the columns. Each bank is sized to be a divisor of a size of an associated hardware register. Assignment of data objects to banks organizes the data in a manner that support efficient query processing that mitigates the quantity of banks required to respond to the query.
摘要:
A method, system, and article are provided for employment of a hybrid layout of representation of data objects in computer memory. Columns of the database are separated based upon a classification of the columns. A vertical partition in the form of a bank is provided to receive an assignment of one or more data objects identified in the columns. Each bank is sized to be a divisor of a size of an associated hardware register. Assignment of data objects to banks organizes the data in a manner that support efficient query processing that mitigates the quantity of banks required to respond to the query.
摘要:
Systems, methods, and other embodiments associated with real-time text indexing are described. One example method includes receiving a document for indexing in a search system that includes a mature index and indexing the received document in a staging index. The staging index may be stored in direct access memory associated with query processing that does not degrade query performance even when postings become fragmented. The staging index and the mature text index are accessed to process queries on the search system. The example method may also include periodically merging the staging index into the mature index based on query feedback.