Abstract:
A method, system, and computer program product. The method for non-intrusive redeployment of a standby database facility comprises configuring a database system having a shared lock manager process to synchronize two or more concurrent access instances, then granting lock requests for access to a cache of database blocks. At some moment in time, the shared lock manager process may fail, and a monitor process detects the failure or other stoppage of the shared lock manager process. A new shared lock manager process and other processes are started, at least one of which serves for identifying the database blocks in the cache that have not yet been written to the database. The identified blocks are formed into a recovery set of redo operations. During this time, incoming requests for access to the cache of database blocks are briefly blocked, at least until the recovery set of redo operations has been formed.
Abstract:
Techniques are described for maintaining coherency of a portion of a database object populated in the volatile memories of multiple nodes in a database cluster. The techniques involve maintaining a local invalidation bitmap for chunks of data stored in memory in each particular node in the cluster by tracking locks granted by a lock manager. During a pre-loading operation, each given node requests a set of shared locks associated with the chunks of data to be store in the given node's memory. When a request to release one of these shared locks occurs, the in-memory copy of those data items may be invalidated in the node releasing its shared lock.
Abstract:
Techniques are herein described for loading a portion of a database object into volatile memory without blocking database manipulation language transactions. The techniques involve invalidating data items loaded from blocks affected by a transaction, referred to as a straddling transaction that started before the load time and committed after the load time. Identifying these straddling transactions involves reviewing one or more transaction lists associated with the set of data items loaded in memory. The transaction list may be read in reverse temporal order of commit to identify a transaction meeting the criteria of starting before the load start, not committing before the load time, and affecting a data item loaded in memory.
Abstract:
Techniques are provided for managing cached data objects in a mixed workload environment. In an embodiment, a database system receives request to access a target data object. The database system determines whether the request to access the target data object is associated with a first type of workload or a second type of workload. In response to determining that the request is associated with the first type of workload, the target data object replaces a least recently used data object in a cache. In response to determining that the request is associated with the second type of workload, the target data object is cached based on an associated access-level value.
Abstract:
Techniques are provided for managing cached data objects in a mixed workload environment. In an embodiment, a database system receives request to access a target data object. The database system determines whether the request to access the target data object is associated with a first type of workload or a second type of workload. In response to determining that the request is associated with the first type of workload, the target data object replaces a least recently used data object in a cache. In response to determining that the request is associated with the second type of workload, the target data object is cached based on an associated access-level value.
Abstract:
Techniques are herein described for loading a portion of a database object into volatile memory without blocking database manipulation language transactions. The techniques involve invalidating data items loaded from blocks affected by a transaction, referred to as a straddling transaction that started before the load time and committed after the load time. Identifying these straddling transactions involves reviewing one or more transaction lists associated with the set of data items loaded in memory. The transaction list may be read in reverse temporal order of commit to identify a transaction meeting the criteria of starting before the load start, not committing before the load time, and affecting a data item loaded in memory.