Abstract: The present disclosure relates to a system and techniques for preventing corruption of snapshot data by limiting the visibility of committed data. To do this, the system may maintain an index that indicates the highest transaction identifier value such that no future commits will have a transaction identifier less than or equal to the indexed transaction identifier value. In embodiments, if a read is performed, only transactions having a transaction identifier less than or equal to the index value can be read. Each time that a transaction is committed, the index value is updated to the transaction identifier for the transaction having the highest transaction identifier without any intermediary transactions.

Abstract: Techniques for enabling efficient data migration between data stores with no downtime are disclosed. A distributed computing system can be implemented with an initial data store and a target data store. During the migration of a portion of the data from the initial data store to the target data store, the distributed computing system can receive requests to create data entities or launch workflow instances at the data stores. The system can determine whether the initial data store or the target data store has been designated the primary data store for handling the requests. The system can also determine whether the initial data store or the target data store contain a key associated with the request. If the key is present in either of the data stores, the system may abort the creation of the data entity.

Abstract: The present disclosure relates to a system and techniques for preventing corruption of snapshot data by limiting the visibility of committed data. To do this, the system may maintain an index that indicates the highest transaction identifier value such that no future commits will have a transaction identifier less than or equal to the indexed transaction identifier value. In embodiments, if a read is performed, only transactions having a transaction identifier less than or equal to the index value can be read. Each time that a transaction is committed, the index value is updated to the transaction identifier for the transaction having the highest transaction identifier without any intermediary transactions.

Abstract: The present disclosure relates to a system and techniques for preventing corruption of snapshot data by limiting the visibility of committed data. To do this, the system may maintain an index that indicates the highest transaction identifier value such that no future commits will have a transaction identifier less than or equal to the indexed transaction identifier value. In embodiments, if a read is performed, only transactions having a transaction identifier less than or equal to the index value can be read. Each time that a transaction is committed, the index value is updated to the transaction identifier for the transaction having the highest transaction identifier without any intermediary transactions.

Abstract: The present disclosure relates to a system and techniques for preventing corruption of snapshot data by limiting the visibility of committed data. To do this, the system may maintain an index that indicates the highest transaction identifier value such that no future commits will have a transaction identifier less than or equal to the indexed transaction identifier value. In embodiments, if a read is performed, only transactions having a transaction identifier less than or equal to the index value can be read. Each time that a transaction is committed, the index value is updated to the transaction identifier for the transaction having the highest transaction identifier without any intermediary transactions.