Abstract: Authorization is divided between a control plane and a data plane for sharing database data. A producer database engine can create a shared database via a data plane interface. A producer can then authorize access to the shared database via a control plane interface to a consumer. A consumer can associate the authorization granted to the consumer with a consumer database engine via the control plane interface.

Abstract: A primary query engine may receive a query and determine whether the query is eligible for performance at a secondary query engine. If eligible, the primary query engine may evaluate the availability of the first query engine to perform the query. The first query engine may determine whether to assign the query to the primary query engine or to the secondary query according to availability evaluation. For queries assigned to the secondary query engine, the primary query engine may send a request to the secondary query engine to being processing of the query.

Abstract: Methods for implementing insert, update, and delete events of a change-data-capture log in transactional order to a representation of a transactional table are disclosed. Insert events may be applied and committed to the representation, while delete events may be buffered and committed to a shadow table. Such buffering may allow the delete events to be applied and committed as a batch to the given representation as a later background operation, allowing for an optimized application of the change-data-capture log to the representation. Once the delete events are committed to the representation, they are removed from the shadow table. Update events may be similarly treated in which the insert event component of the update event is applied and committed to the representation while the delete event component is committed to the shadow table, before being later committed to the representation and removed from the shadow table.

Abstract: Methods for replicating transactional tables of a transactional database to an analytical database and maintaining updates to those transactional table representations are disclosed. Snapshots of the transactional tables are provided to the analytical database via a transport mechanism, such as a data storage service or a data streaming service, and stored at the analytical database. Then, checkpoints comprising portions of a change-data-capture log that has recorded transactional changes to the transactional tables of the transactional database are provided to the analytical database via the same or different transport mechanism and used to commit those transactional changes to the snapshot representations. The snapshot representations may be used to respond to incoming analytical queries in order to provide real-time querying results.

Abstract: Queries to a consistent view of a data set across different types of query engines are performed. Portions of a query received at a first type of query engine that can be performed at a different type of a query engine can be identified. A consistent view of a data set stored in a common data store can be provided by the first type of query engine to the second query engine. When the different type of query engine performs the portion of the query, the different type of query engine applies the consistent view of the data set. A result for the query can be returned by the first type of query engine based on results from the different type of query engine.

Abstract: Compiled portions of code generated to perform a query plan at a query engine may be shared with other query engines. A data store, separate from the query engines, may store compiled portions of query code generated for different queries. If a query engine does not have a locally stored compiled portion of query code, then the separate data store may be accessed in order to obtain a compiled portion of query code, allowing reuse of compiled query code across different queries engines for queries directed to different databases.

Abstract: Online restore may be performed between databases with different topologies while applying a custom data distribution. A request to restore a database into a different topology of nodes may be received. A plan to move different portions of the database from a current topology to the new topology made using a general distribution scheme. The plan may be performed to move the different portions of the database into the new topology and the database made available for access using the new topology. A background process may be applied to modify the distribution of the database at the new topology to match a custom distribution scheme that was implemented at the current topology.

Abstract: Compiled portions of code generated to perform a query plan at a query engine may be shared with other query engines. A data store, separate from the query engines, may store compiled portions of query code generated for different queries. If a query engine does not have a locally stored compiled portion of query code, then the separate data store may be accessed in order to obtain a compiled portion of query code, allowing reuse of compiled query code across different queries engines for queries directed to different databases.

Abstract: A database service may distribute resources across different geographic locations or other infrastructures to increase availability of the resources and may provide multiple locations to access resources and isolate failure of resources to a respective location or infrastructure. The processing resources in differing fault tolerance zones may be able to continue operating in the event of an outage impacting an entire fault tolerance zone. The database service may generate a supporting processing cluster in the differing fault tolerance zone that handles at least a portion of the access requests of an initial processing cluster. The database service may provision the supporting processing cluster in a separate fault tolerance zone that has a similar capacity and may provision and maintain the cluster in order to preclude the potential of not having sufficient capacity to recover upon failure of a single fault tolerance zone.

Abstract: Scaling of query processing resources for efficient utilization and performance is implemented for a database service. A query is received via a network endpoint associated with a database managed by a database service. Respective response times predicted for the query using different query processing configurations available to perform the query are determined. Those query processing configurations with response times that exceed a variability threshold determined for the query may be excluded. A remaining query processing configuration may then be selected to perform the query.

Abstract: When a query is received by a stateful data processing service, the service determines, for each table scan (and associated operations) of a query, whether to select the table scan for execution by a stateless data processing service. The selected table scans are sent to the stateless data processing service for execution, and results are received by the stateful data processing service. The stateful data processing service may also execute other table scans of the query locally, against a local data cache. If the data is not present in the local data cache, then the stateful data processing service will copy the table data into the local data cache before executing the table scan. A query result based on the remote and/or local table scans may then be returned to the client.

Abstract: Online restore may be performed between databases with different topologies while applying a custom data distribution. A request to restore a database into a different topology of nodes may be received. A plan to move different portions of the database from a current topology to the new topology made using a general distribution scheme. The plan may be performed to move the different portions of the database into the new topology and the database made available for access using the new topology. A background process may be applied to modify the distribution of the database at the new topology to match a custom distribution scheme that was implemented at the current topology.

Abstract: Idle periods may be for management actions at processing clusters for managed databases. A leader node of a processing cluster for a managed database may monitor a network endpoint at a proxy service associated with a database managed by the database service. An idle period for the database may be detected. A management action for the processing cluster may be determined to be performed during the detected idle period. The leader node may cause the determined management action to be performed.

Abstract: Scaling of query processing resources for efficient utilization and performance is implemented for a database service. A query is received via a network endpoint associated with a database managed by a database service. Respective response times predicted for the query using different query processing configurations available to perform the query are determined. Those query processing configurations with response times that exceed a variability threshold determined for the query may be excluded. A remaining query processing configuration may then be selected to perform the query.

Abstract: When a query is received by a stateful data processing service, the service determines, for each table scan (and associated operations) of a query, whether to select the table scan for execution by a stateless data processing service. The selected table scans are sent to the stateless data processing service for execution, and results are received by the stateful data processing service. The stateful data processing service may also execute other table scans of the query locally, against a local data cache. If the data is not present in the local data cache, then the stateful data processing service will copy the table data into the local data cache before executing the table scan. A query result based on the remote and/or local table scans may then be returned to the client.

Abstract: A primary query engine may receive a query and determine whether the query is eligible for performance at a secondary query engine. If eligible, the primary query engine may evaluate the availability of the first query engine to perform the query. The first query engine may determine whether to assign the query to the primary query engine or to the secondary query according to availability evaluation. For queries assigned to the secondary query engine, the primary query engine may send a request to the secondary query engine to being processing of the query.

Abstract: A query that references nested data may have sub-expressions included in a subquery for nested data to perform the query. A first query engine may rewrite the query to include one or more sub-expressions that reference the nested data into a subquery for the nested data as part of generating a plan to perform the query. A second query engine may then be caused to perform the subquery for the nested data. A result of the query may be inclusive of the performance of the subquery at the second query engine.

Abstract: A primary query engine may receive a query and determine whether the query is eligible for performance at a secondary query engine. If eligible, the primary query engine may evaluate the availability of the first query engine to perform the query. The first query engine may determine whether to assign the query to the primary query engine or to the secondary query according to availability evaluation. For queries assigned to the secondary query engine, the primary query engine may send a request to the secondary query engine to being processing of the query.

Abstract: Caching results of sub-queries to different locations in a data store may be performed. A database query may be received that causes different storage engines to perform sub-queries to different locations in a data store that stores data for a database. The results of the sub-queries may be stored in a cache. When another database query is received, sub-queries generated to perform the other database query that are the same as one or more of the previously performed sub-queries may obtain the results of the sub-queries from the cache instead of performing the sub-queries again.

Abstract: A method includes encoding, by an encoding engine, consecutive sections of a received data stream that includes a stream of values. The encoding includes identifying a minimum value in a section of the stream. The encoding includes determining, for each value in the section of the stream, respective differences with the minimum value. An encoded version of the section includes the minimum value and a mask value. The mask value is combined with respective portions of the respective differences to generate the respective differences of each value in the section. The encoded version of the section further includes the respective portions of the respective differences.