Abstract: Read-only nodes of a distributed database system may implement index structure navigation using page versions. A read request may be received at a read only node of a distributed database for select data. Data pages linked together to form an index structure for data stored for the distributed database may be navigated according to versions maintained for the data pages in order to identify one or more locations to access for the select data. One or more prior versions of data pages may be selected as part navigating the index structure according to a consistent view of the distributed database associated with the read request. Change notifications may also be received at the read-only node modifying the data pages of the index structure. The index structure modifications may be applied without blocking the index structure navigation for servicing the read request.

Abstract: Aspects of the subject matter described herein relate to reducing update conflicts when maintaining views. In aspects, a transaction in snapshot isolation may update a materialized view. Instead of being able to view the update within the transaction, the update is hidden to prevent the transaction from obtaining inconsistent data. When a transaction is not supposed to see an update to a materialized view that occurs within the transaction, additional information associated with the materialized view may indicate this. When a query of the materialized view is made within the transaction, the query engine may use the additional information to exclude data from the update in the result.

Abstract: A distributed database system may implement incremental updates to user transaction state at read-only nodes of the distributed database. A read-write node of the distributed database may determine a change to transaction state for a user transaction initiated at the read-write node. The read-write node may send a notification of the change to the transaction state for the user transaction to a read-only node in order to incrementally update the transaction state for the user transaction at the read-only node. The read-only node may receive the notification of the change to the transaction state and update in-memory system metadata to apply the change to the transaction state for the user transaction. A view of the distributed database may be made available at the read-only node for read requests according to the updated transaction state for the user transaction.

Abstract: Read-only nodes of a distributed database system may perform replicated database startup for common database storage. A read-only node may request a view of a database from a master node to initialize the read-only node for servicing queries. An indication of the view may be received and portions of data maintained for the distributed database may be read from a common data store maintaining the data for the database according to the indicated view of the database. In-memory data structures at the read-only node for servicing queries may be initialized based on the portions of data read from the common data store. The read-only node may then be made available for servicing queries.

Abstract: Read-only nodes of a distributed database system may perform replicated database startup for common database storage. A read-only node may request a view of a database from a master node to initialize the read-only node for servicing queries. An indication of the view may be received and portions of data maintained for the distributed database may be read from a common data store maintaining the data for the database according to the indicated view of the database. In-memory data structures at the read-only node for servicing queries may be initialized based on the portions of data read from the common data store. The read-only node may then be made available for servicing queries.

Abstract: Read-only nodes of a distributed database system may implement index structure navigation using page versions. A read request may be received at a read only node of a distributed database for select data. Data pages linked together to form an index structure for data stored for the distributed database may be navigated according to versions maintained for the data pages in order to identify one or more locations to access for the select data. One or more prior versions of data pages may be selected as part navigating the index structure according to a consistent view of the distributed database associated with the read request. Change notifications may also be received at the read-only node modifying the data pages of the index structure. The index structure modifications may be applied without blocking the index structure navigation for servicing the read request.

Abstract: Aspects of the subject matter described herein relate to reducing update conflicts when maintaining views. In aspects, a transaction in snapshot isolation may update a materialized view. Instead of being able to view the update within the transaction, the update is hidden to prevent the transaction from obtaining inconsistent data. When a transaction is not supposed to see an update to a materialized view that occurs within the transaction, additional information associated with the materialized view may indicate this. When a query of the materialized view is made within the transaction, the query engine may use the additional information to exclude data from the update in the result.

Abstract: Read-only nodes of a distributed database system may implement index structure navigation using page versions. A read request may be received at a read only node of a distributed database for select data. Data pages linked together to form an index structure for data stored for the distributed database may be navigated according to versions maintained for the data pages in order to identify one or more locations to access for the select data. One or more prior versions of data pages may be selected as part navigating the index structure according to a consistent view of the distributed database associated with the read request. Change notifications may also be received at the read-only node modifying the data pages of the index structure. The index structure modifications may be applied without blocking the index structure navigation for servicing the read request.

Abstract: A distributed database system may efficiently replicate distributed storage system changes on one or more read-only nodes. Storage metadata that indicates an access scheme for obtaining data for a particular view of the database from a distributed storage system may be maintained at a read-only node. An update to the storage metadata may be received that indicates a change to the distributed storage system that affects the validity of read requests for a different particular view of the database. In some embodiments, the change may indicate which storage nodes may be storing data according to the different particular view of the database, such as a change in membership of a protection group for the data at the distributed storage system. The storage metadata at the read-only node may be updated according to the received update such that a subsequent read request for the different particular view of the database is sent to the distributed storage system according to the updated access scheme.

Abstract: Aspects of the subject matter described herein relate to reducing update conflicts when maintaining views. In aspects, a transaction in snapshot isolation may update a materialized view. Instead of being able to view the update within the transaction, the update is hidden to prevent the transaction from obtaining inconsistent data. When a transaction is not supposed to see an update to a materialized view that occurs within the transaction, additional information associated with the materialized view may indicate this. When a query of the materialized view is made within the transaction, the query engine may use the additional information to exclude data from the update in the result.

Abstract: A distributed database system may efficiently replicate system transactions one or more read-only nodes. An update to a distributed database may be received. One or more system transactions may be performed to apply the update. For each system transaction, one or more change notifications may be generated which indicate changes to be applied in order to perform the system transaction. A particular one of the change notifications may be identified as the last change to be applied in order to complete the system transaction. The change notifications may be sent to one or more read-only nodes. The read-only nodes may process read requests for the distributed database system. The identified change notification may indicate to the read-only nodes the last change to be applied prior to presenting a state of the database that includes the system transaction when servicing read requests.

Abstract: Aspects of the subject matter described herein relate to reducing update conflicts when maintaining views. In aspects, a transaction in snapshot isolation may update a materialized view. Instead of being able to view the update within the transaction, the update is hidden to prevent the transaction from obtaining inconsistent data. When a transaction is not supposed to see an update to a materialized view that occurs within the transaction, additional information associated with the materialized view may indicate this. When a query of the materialized view is made within the transaction, the query engine may use the additional information to exclude data from the update in the result.