Abstract: A maximum lag between data stores can be specified that corresponds to a recovery point objective defined in a service level agreement. Lag can be monitored during a data replication between a primary data store and a secondary data store located in geographically different regions. Activity on the primary data store including incoming data transactions can be throttled as a function of the lag and the maximum lag.

Abstract: A maximum lag between data stores can be specified that corresponds to a recovery point objective defined in a service level agreement. Lag can be monitored during a data replication between a primary data store and a secondary data store located in geographically different regions. Activity on the primary data store including incoming data transactions can be throttled as a function of the lad and the maximum lag.

Abstract: A maximum lag between data stores can be specified that corresponds to a recovery point objective defined in a service level agreement. Lag can be monitored during a data replication between a primary data store and a secondary data store located in geographically different regions. Activity on the primary data store including incoming data transactions can be throttled as a function of the lag and the maximum lag.

Abstract: Streaming database replication is provided by merging a stream of user transactions with a stream of copy transactions comprising copy data into a combined stream on a source. A target receives a single stream that includes copy transaction and concurrent user transactions in an order that enables conflicts between data being copied and user transactions to be handled correctly. Furthermore, locks applied to data subject to a copy transaction or user transaction can be released once the copy transaction or user transaction is added to the combined stream.

Abstract: A maximum lag between data stores can be specified that corresponds to a recovery point objective defined in a service level agreement. Lag can be monitored during a data replication between a primary data store and a secondary data store located in geographically different regions. Activity on the primary data store including incoming data transactions can be throttled as a function of the lag and the maximum lag.

Abstract: Streaming database replication is provided by merging a stream of user transactions with a stream of copy transactions comprising copy data into a combined stream on a source. A target receives a single stream that includes copy transaction and concurrent user transactions in an order that enables conflicts between data being copied and user transactions to be handled correctly. Furthermore, locks applied to data subject to a copy transaction or user transaction can be released once the copy transaction or user transaction is added to the combined stream.

Abstract: Architecture that addresses an end-to-end solution for logical transactional replication from a shared-nothing clustered database management system, which uses adaptive cloning for high availability. This can be time based using a global logical timestamp. The disclosed architecture, used for refreshing stale clones, does not preserve user transaction boundaries, which is a more complex situation than where the boundaries are preserved. In such a scenario it is probable that for a given data segment no clone of the segment may contain the complete user transaction history, and hence, the history has to be pieced together from the logs of multiple different clones. This is accomplished such that log harvesting is coordinated with the clone state transitions to ensure the correctness of logical replication.

Abstract: Architecture that addresses an end-to-end solution for logical transactional replication from a shared-nothing clustered database management system, which uses adaptive cloning for high availability. This can be time based using a global logical timestamp. The disclosed architecture, used for refreshing stale clones, does not preserve user transaction boundaries, which is a more complex situation than where the boundaries are preserved. In such a scenario it is probable that for a given data segment no clone of the segment may contain the complete user transaction history, and hence, the history has to be pieced together from the logs of multiple different clones. This is accomplished such that log harvesting is coordinated with the clone state transitions to ensure the correctness of logical replication.

Abstract: Aspects of the subject matter described herein relate to data change ordering in multi-log based replication. In aspects, local seeds are maintained for subtransactions involved in a transaction, where each subtransaction may occur on a different node that hosts one or more database fragments involved in the transaction. When a subtransaction communicates with another subtransaction in a transaction, the subtransaction sends its local seed to the other subtransaction. The receiving subtransaction compares its local seed with the received seed and updates its local seed if the received seed is logically after its local seed. A subtransaction uses a local seed to generate sequence identifiers for changes made by the subtransaction. These identifiers allow data changes of a transaction that are made on multiple nodes to be partially ordered relative to other changes made during the transaction.

Abstract: Architecture that addresses an end-to-end solution for logical transactional replication from a shared-nothing clustered database management system, which uses adaptive cloning for high availability. This can be time based using a global logical timestamp. The disclosed architecture, used for refreshing stale clones, does not preserve user transaction boundaries, which is a more complex situation than where the boundaries are preserved. In such a scenario it is probable that for a given data segment no clone of the segment may contain the complete user transaction history, and hence, the history has to be pieced together from the logs of multiple different clones. This is accomplished such that log harvesting is coordinated with the clone state transitions to ensure the correctness of logical replication.

Abstract: Methods, systems, and computer-readable media of database mirroring are disclosed. A particular method includes initiating a transaction that modifies one or more pages of a first database. Each page includes a structure modification operation (SMO) bit and initiating the transaction includes setting the SMO bit of each of the one or more pages to a first value. One or more first records are created at a transaction log of the first database. The transaction log is useable at a second database to mirror the transaction. Each first record indicates the setting of a SMO bit of a particular page to the first value. The database transaction is performed, and the SMO bit of each of the one or more pages is set to a second value. One or more second records are created at the transaction log, each second record indicating the setting of a SMO bit of a particular page to the second value. The method includes committing the transaction.

Abstract: Aspects of the subject matter described herein relate to data change ordering in multi-log based replication. In aspects, local seeds are maintained for subtransactions involved in a transaction, where each subtransaction may occur on a different node that hosts one or more database fragments involved in the transaction. When a subtransaction communicates with another subtransaction in a transaction, the subtransaction sends its local seed to the other subtransaction. The receiving subtransaction compares its local seed with the received seed and updates its local seed if the received seed is logically after its local seed. A subtransaction uses a local seed to generate sequence identifiers for changes made by the subtransaction. These identifiers allow data changes of a transaction that are made on multiple nodes to be partially ordered relative to other changes made during the transaction.