ADAPTIVELY OVERLAPPING THE WRITING OF REDO LOG RECORDS

    公开(公告)号:US20250094411A1

    公开(公告)日:2025-03-20

    申请号:US18598122

    申请日:2024-03-07

    Abstract: The present disclosure relates to adaptively overlapping redo writes. A log writer, while operating in a thin mode, may assign a first log writer group of a plurality of log writer groups to write one or more first redo log records to an online redo log in response to determining that a pipelining parameter is satisfied. The thin mode may be associated with one or more target sizes that are less than one or more target sizes associated with a thick mode. The log writer may determine to operate the thick mode based at least in part on at least a portion of the plurality of log writer groups being unavailable to write one or more second redo log records to the online redo log. The log writer, while operating in the thick mode, may assign a second log writer group of the plurality of log writer groups to write one or more second redo log records from the log buffer to the online redo log in response to determining that an amount of redo log records in the log buffer meets one of the one or more target sizes associated with the thick mode. The log writer, while operating in the thick mode, may assign a third log writer group of the plurality of log writer groups to write one or more second redo log records from the log buffer to the online redo log in response to determining that a highest busy group number meets or exceeds a core threshold.

    METHOD AND SYSTEM FOR AUTOMATIC MAINTENANCE OF STANDBY DATABASES FOR NON-LOGGED WORKLOADS

    公开(公告)号:US20190095297A1

    公开(公告)日:2019-03-28

    申请号:US15828146

    申请日:2017-11-30

    Abstract: A computer program product, system, and computer implemented method for automatic maintenance of standby databases for non-logged workloads, the process comprising: maintaining a redo stream of redo records sent from a primary database to a standby database, identifying a change made at the primary database for which a redo record was not created, inserting a placeholder redo record into the redo stream corresponding to the change identified at the primary database for which the redo record was not created, sending, to the standby database, a copy of one or more data blocks corresponding to the change that is associated with the placeholder redo record, receiving the placeholder redo record from the redo stream, identifying the copy of the one or more data blocks sent from the primary database corresponding to the placeholder redo record, and applying the copy of one or more data blocks to update the standby database.

    INSTANCE RECOVERY USING BLOOM FILTERS
    4.
    发明申请

    公开(公告)号:US20180300204A1

    公开(公告)日:2018-10-18

    申请号:US15489482

    申请日:2017-04-17

    Abstract: Techniques related to instance recovery using Bloom filters are disclosed. A multi-node node database management system (DBMS) includes a first database server instance and a second database server instance. A recovery set includes a set of data blocks that have been modified by a first database server instance and not persisted. A Bloom filter is generated to indicate whether data blocks are excluded from the recovery set. The Bloom filter is sent to the second database server instance, which determines whether the Bloom filter indicates that a particular data block is excluded from the recovery set. Based on determining that the Bloom filter indicates that the particular data block is excluded from the recovery set, access to the particular data block is granted.

    Multi-instance redo apply
    7.
    发明授权

    公开(公告)号:US09495431B2

    公开(公告)日:2016-11-15

    申请号:US14067129

    申请日:2013-10-30

    Abstract: A method, apparatus, and system for multi-instance redo apply is provided for standby databases. A multi-instance primary database generates a plurality of redo records, which are received and applied by a physical standby running a multi-instance standby database. Each standby instance runs a set of processes that utilize non-blocking, single-task threads for high parallelism. At each standby instance for the multi-instance redo, the plurality of redo records are merged into a stream from one or more redo strands in logical time order, distributed to standby instances according to determined apply slave processes using an intelligent workload distribution function, reemerged after receiving updates from remote instances, and applied in logical time order by the apply slave processes. Redo apply progress is tracked at each instance locally and also globally, allowing a consistent query logical time to be maintained and published to service database read query requests concurrently with the redo apply.

    Instantaneous unplug of pluggable database from one container database and plug into another container database
    8.
    发明授权
    Instantaneous unplug of pluggable database from one container database and plug into another container database 有权
    从一个容器数据库中即时拔出可插拔数据库,并插入另一个容器数据库

    公开(公告)号:US09396220B2

    公开(公告)日:2016-07-19

    申请号:US14202091

    申请日:2014-03-10

    CPC classification number: G06F17/303 G06F17/30371 G06F17/30575

    Abstract: A pluggable database is transported between a source DBMS and a destination DBMS, in a way that minimizes downtime of the pluggable database. While a copy of the pluggable database is being made at the destination DBMS, transactions continue to execute against the pluggable database at the source DBMS and change the pluggable database. Eventually, the transactions terminate or cease executing. Redo records generated for the transactions are applied to the copy of the pluggable database at the source DBMS. Undo records generated for at least some of the transactions may be stored in a separate undo log and transported to the destination DBMS. The transported pluggable database is synchronized at a destination DBMS in a “pluggable-ready state”, where it may be plugged into the destination container DBMS.

    Abstract translation: 可插拔数据库在源DBMS和目标DBMS之间传输,从而最大限度地减少可插拔数据库的停机时间。 虽然目标DBMS正在进行可插拔数据库的副本,但是事务将继续针对源DBMS上的可插拔数据库执行,并更改可插拔数据库。 最终,交易终止或停止执行。 为事务生成的重做记录应用于源DBMS的可插拔数据库的副本。 至少为某些事务生成的撤销记录可以存储在单独的撤销日志中,并传送到目标DBMS。 传输的可插拔数据库在目标DBMS上以“可插拔就绪状态”进行同步,可以插入到目标容器DBMS中。

    HIGH PERFORMANCE LOG-BASED PROCESSING
    9.
    发明申请
    HIGH PERFORMANCE LOG-BASED PROCESSING 审中-公开
    高性能基于日志的处理

    公开(公告)号:US20140196055A1

    公开(公告)日:2014-07-10

    申请号:US14059352

    申请日:2013-10-21

    Abstract: Each of a plurality of Worker processes are allowed to perform any and all of the following tasks involving logged work items: (1) reading a subset of the work items from a log; (2) sequentially ordering work items for corresponding data objects; (3) applying a sequentially ordered set of work items to a corresponding data object; and (4) transmitting a subset of work items to a Worker process running on another database server in a cluster, if necessary. These tasks can be performed concurrently, at will, and as available, by the Worker processes. An improved checkpointing technique eliminates the need for the Worker processes to get to a synchronization point and stop. Instead, a Coordinator process examines the current state of progress of the Worker processes and computes a past point in the sequence of work items at which all work items before that point have been completely processed, and records this point as the checkpoint.

    Abstract translation: 允许多个Worker进程中的每一个执行涉及记录的工作项的任何和所有以下任务:(1)从日志读取工作项的子集; (2)顺序排列相应数据对象的工作项; (3)将顺序排列的工作项集合应用于对应的数据对象; (4)如果需要,将工作项的子集发送到在群集中的另一数据库服务器上运行的工作进程。 这些任务可以在工作进程的同时,随意和可用的情况下执行。 改进的检查点技术消除了Worker进程到达同步点并停止的需要。 相反,协调器进程将检查工作进程的当前状态,并计算工作项序列中的过去点,在此之前,该点之前的所有工作项都已完全处理,并将此点记录为检查点。

    INCREASING OLTP THROUGHPUT BY IMPROVING THE PERFORMANCE OF LOGGING USING PERSISTENT MEMORY STORAGE

    公开(公告)号:US20250053299A1

    公开(公告)日:2025-02-13

    申请号:US18929241

    申请日:2024-10-28

    Abstract: In an embodiment, before modifying a persistent ORL (ORL), a database management system (DBMS) persists redo for a transaction and acknowledges that the transaction is committed. Later, the redo is appended onto the ORL. The DBMS stores first redo for a first transaction into a first PRB and second redo for a second transaction into a second PRB. Later, both redo are appended onto an ORL. The DBMS stores redo of first transactions in volatile SRBs (SLBs) respectively of database sessions. That redo is stored in a volatile shared buffer that is shared by the database sessions. Redo of second transactions is stored in the volatile shared buffer, but not in the SLBs. During re-silvering and recovery, the DBMS retrieves redo from fast persistent storage and then appends the redo onto an ORL in slow persistent storage. After re-silvering, during recovery, the redo from the ORL is applied to a persistent database block.

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