Patent application number | Description | Published |
20140279900 | PLACE SNAPSHOTS - A database system may maintain a plurality of log records at a distributed storage system. Each of the plurality of log records may be associated with a respective change to a data page. A snapshot may be generated that is usable to read the data as of a state corresponding to the snapshot. Generating the snapshot may include generating metadata that is indicative of a particular log identifier of a particular one of the log records. Generating the snapshot may be performed without additional reading, copying, or writing of the data. | 09-18-2014 |
20140279920 | LOG RECORD MANAGEMENT - A database system may maintain a plurality of log records at a distributed storage system. Each of the plurality of log records may be associated with a respective change to a data page. The plurality of log records may be transformed (e.g., cropped, prune, reduce, fused, deleted, merged, added, etc.). | 09-18-2014 |
20140279929 | DATABASE SYSTEM WITH DATABASE ENGINE AND SEPARATE DISTRIBUTED STORAGE SERVICE - A database system may include a database service and a separate distributed storage service. The database service (or a database engine head node thereof) may be responsible for query parsing, optimization, and execution, transactionality, and consistency, while the storage service may be responsible for generating data pages from redo log records and for durability of those data pages. For example, in response to a write request directed to a particular data page, the database engine head node may generate a redo log record and send it, but not the data page, to a storage service node. The storage service node may store the redo log record and return a write acknowledgement to the database service prior to applying the redo log record. The server node may apply the redo log record and other redo log records to a previously stored version of the data page to create a current version. | 09-18-2014 |
20140279930 | FAST CRASH RECOVERY FOR DISTRIBUTED DATABASE SYSTEMS - A distributed database system may implement fast crash recovery. Upon recovery from a database head node failure, a connection with one or more storage nodes of a distributed storage system storing data for a database implemented by the database head node may be established. Upon establishment of the connection with the storage nodes, that database may be made available for access, such as for various access requests. In various embodiments, redo log records may not be replayed in order to provide access to the database. In at least some embodiments, the storage nodes may provide a current state of data stored for the database in response to requests. | 09-18-2014 |
20140279931 | SYSTEM-WIDE CHECKPOINT AVOIDANCE FOR DISTRIBUTED DATABASE SYSTEMS - A database system may maintain a plurality of log records at a distributed storage system. Each of the plurality of log records may be associated with a respective change to a data page. Upon detection of a coalesce event for a particular data page, log records linked to the particular data page may be applied to generate the particular data page in its current state. Detecting the coalesce event may be a determination that the number of log records linked to the particular data page exceeds a threshold. | 09-18-2014 |
20140324785 | EFFICIENT READ REPLICAS - A database system may receive a write request that specifies a modification to be made to a particular data record stored by the database system. A log record representing the modification to be made to the particular data record may be sent to a storage service of the database system. An indication (e.g., log record or other indication) that indicates a cached version of the particular data record stored in a read replica's cache is stale may be sent to a read replica. For a subsequent read of the particular data record received by the read replica, the read replica may request the particular data record from the storage service. | 10-30-2014 |
20140337393 | TRANSACTION ORDERING - Nodes of a database service may receive a read request to perform a read of a record stored by the database service and a transaction request to perform a transaction to the record. First and second indications of time may be associated with the read and transaction, respectively. A potential read anomaly (e.g., fuzzy read, read skew, etc.) may be detected based, at least in part, on a determination that the first indication of time is within a threshold value of the second indication of time. In response to detecting the potential read anomaly, the read may be performed after the transaction specified by the transaction request, regardless of whether the first indication of time is indicative of an earlier point in time than the second indication of time. | 11-13-2014 |
20150261610 | SELF-DESCRIBING DATA BLOCKS OF A MINIMUM ATOMIC WRITE SIZE FOR A DATA STORE - Self-describing data blocks of a minimum atomic write size may be stored for a data store. Data may be received for storage in a data block of a plurality of data blocks at a persistent storage device that are equivalent to a minimum atomic write size for the persistent storage device. Metadata may be generated for the data that includes an error detection code which is generated for the data and the metadata together. The data and the metadata are sent to the persistent storage device to store together in the data block. An individual atomic write operation may write together the data and the metadata in the data block. When accessed, the error detection code is applicable to detect errors. The metadata may also be applicable to determine whether the data is stored for a currently assigned purpose or a previously assigned purpose of the data block. | 09-17-2015 |