Abstract: Optimistic concurrency may be implemented for multiple writers to a database. Writes to a database from different writers may succeed unless a conflict is detected at the data store for the database. For detected conflicts, a request to resolve the conflict between writes may be submitted to a primary writer, which may determine and provide a resolution of the conflict to the conflicting writers. The data store may then be updated to commit the selected write identified by the resolution of the conflict.

Abstract: A database system may add a read-only query engine to perform read-only queries associated with points-in-time of a database. In various embodiments, the read-only query engine may be added in response to a manual request, an automatic refresh of a network endpoint, a query specifying a point-in-time, or a connection request. The read-only query engine may perform the point-in-time queries on a version the database at the point-in-time and return results for the queries. Upon completion of the queries or at a determined time, the database system may remove the read-only query engine. The specified point-in-time may refer to a current time, a prior time, or a future time with respect to the current time.

Abstract: A database system may add a read-only query engine to perform read-only queries associated with points-in-time of a database. In various embodiments, the read-only query engine may be added in response to a manual request, an automatic refresh of a network endpoint, a query specifying a point-in-time, or a connection request. The read-only query engine may perform the point-in-time queries on a version the database at the point-in-time and return results for the queries. Upon completion of the queries or at a determined time, the database system may remove the read-only query engine. The specified point-in-time may refer to a current time, a prior time, or a future time with respect to the current time.

Abstract: A point-in-time clone may be created for a database. A request to create the point-in-time clone may be received. The clone may be provided with access to a storage for the database that stores a history of modifications to the database applicable to return data of the database according to a state of the data at the specified point in time. The clone may then be updated so that the updates made to the clone are stored for subsequent access by the clone.

Abstract: Techniques for distributed database storage utilizing split volume types for redo log records and change log records are described. A database engine sends redo log data to a first set of page storage nodes and change log data to a second set of tuple storage nodes, where the change log data is stored in an indexed manner Client access to change log data may be provided through a separate set of streaming storage servers instead of through the database engine.

Abstract: Techniques are described for enabling a relational database service of a cloud provider network to provide online restore or “backtrack” capabilities that are unlimited in terms of an amount of time in the past to which a database can be restored. Database systems typically provide restoration capabilities that allow users to undo or revert to a prior state of the database. Restoring a database to a prior state can be useful in many different scenarios. For example, a user might restore a database to remove or rollback errors introduced into a database as a result of inadvertent changes to data or to a schema of the data stored in the database. As another example, database administrators or other users can use restore operations as part of testing modifications to a database schema when developing applications or other tools that use the database.

Abstract: Online restore operations for a database engine can be performed. A request to restore a database to a previous state can be received. Previously stored content of the database, such as snapshot stored prior to the previous state, can be identified along with log records describing changes to be made to the content prior to the previous state. State information in a query engine can be updated based on the previously stored content and log records so that queries can be processed based on the state information at the database restore to the previous state.

Abstract: Online restore operations for a database engine can be performed. A request to restore a database to a previous state can be received. Previously stored content of the database, such as snapshot stored prior to the previous state, can be identified along with log records describing changes to be made to the content prior to the previous state. State information in a query engine can be updated based on the previously stored content and log records so that queries can be processed based on the state information at the database restore to the previous state.

Abstract: Data pages of a database may be shared to create a copy of the database. A request to create a copy of the database may be received. Pointers to the data pages in the data store may be generated and stored as part of the copy of the database. When a request to read a data page in the copy of the database is received, the pointer to the data page may be accessed and the data page read from the database. When a request to modify a data page in the copy of the database is received, a modified version of the data page may be stored as part of the copy of the database and the pointer updated to point to the modified version of the data page.