Abstract: A system performs masking of data stored in a database. The system receives change logs from a source database and masks the change logs to generate masked change logs. The system stores the masked change logs in a pre-buffer. If the system determines that the set of masked change logs stored in the pre-buffer corresponds to a complete transaction, the system determines whether any conflicts exist between masked change logs stored in the pre-buffer and masked change logs stored in a main buffer. If the system identifies conflicts, the system applies the masked change logs stored in the main buffer to a masked replica database. This causes the system to move masked change logs corresponding to a complete transaction from the pre-buffer to the main buffer.

Abstract: Information from source databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A source database may contain partitions comprising sets of database tables. A partition is imported into a virtual database created. The database storage system validates the partition before importing, by checking whether the partition includes database tables that refer to database tables outside the partition. A partition imported in a virtual database may be rewinded to an older state or refreshed to a more recent state. Multiple partitions may be included in a virtual database and the state of each partition modified independent of the state of the remaining virtual database including the other partitions. Multiple versions of the same partition corresponding to different points in time are incorporated in the same virtual database, thereby allowing a query to process different versions of the same database table.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.

Abstract: Storage systems store data in a storage pool comprising storage devices or virtual devices. The storage pool may be allocated for a particular purpose. If a virtual device within the storage pool needs to be repurposed, the virtual device is removed from the storage pool. Data is moved from the removed virtual device to one or more target virtual devices. Segments of the source virtual device being removed are copied to target virtual devices. Mapping tables associating source segments with target segments are stored. If the storage system receives a request to access data stored on a virtual device that is removed, the storage system processes the mapping tables to determine where the data is stored.

Abstract: A storage system maintains copies of a source database to allow virtual databases to be provisioned. Transaction logs received from the source database are applied to database blocks stored in the storage system to update the database blocks. The storage system checks if there are defect in the transaction logs of the source database. If a defect in transaction logs is detected, the storage system obtains a latest copy of the source database. The storage system matches database blocks of the received copy with database blocks already available in the storage system to determine whether a corresponding database block is already available in the storage system. If a received database block is different from database blocks already available at the storage system, the received database block is stored in the storage system. The database blocks may be matched using a hash value of the database blocks.

Abstract: Allocation of resources across multiple consumers allows efficient utilization of shared resources. Observed usages of resources by consumers over time intervals are used to determine a total throughput of resources by the consumers. The total throughput of resources is used to determine allocation of resources for a subsequent time interval. The consumers are associated with priorities used to determine their allocations. Minimum and maximum resource guarantees may be associated with consumers. The resource allocation aims to allocate resources based on the priorities of the consumers while aiming to avoid starvation by any consumer. The resource allocation allows efficient usage of network resources in a database storage system storing multiple virtual databases.

Abstract: Database storage systems provide replication capability that allows data of a source database storage system to be replicated to a target database storage system. Virtual databases can be provisioned from the target database system, thereby supporting remote provisioning of virtual databases. The virtual databases on the remote site can be used to perform various operations including read/write of data, refresh, rollback, and so on. Database objects may be deleted on the source database storage system while the corresponding data is used by other entities for example, virtual databases at the target database storage system. The database storage system verifies if an entity being deleted is in use by any other database infrastructure object of the database storage system. A placeholder object maintains the data corresponding to the deleted object. This provides the ability to create geographical distribution networks and support remote provisioning of virtual databases.

Abstract: An application development system allows developers of a software system to manage infrastructure resources during the development and testing process. The application development system allows users to define application containers that comprise components including source code, binaries, and virtual databases used for the application. An application container can be associated with policies that control various aspects of the actions taken using the application container including constraints and access control. The application development system enforces the policies for actions taken by users for the application containers. The encapsulation of policies with the application containers allows users of the application containers to take actions including creating virtual databases, provisioning virtual databases, and the like without requiring system administrators to manage resource issues.

Abstract: A database storage system provides replication capability that allows data from a source database and application specific data from a source application to be replicated respectively to a target database storage system and a target application, thereby creating a virtual database and a virtual application. The database storage system generates a plurality of snapshots of the virtual database at a corresponding plurality of time points and a plurality of snapshots of the virtual application at the corresponding plurality of time points. The database storage system associates the plurality of snapshots of the virtual database with the plurality of snapshots of the virtual application at the corresponding plurality of time points so as to generate a historical time-sequence of concurrent modifications to both the virtual database and the virtual application at the one or more development environments, thereby allowing concurrent read/write and rollback, of data and applications.

Abstract: A database storage system allows users to modify the state of a virtual database. The database storage system provides a respective virtual database (VDB) at a respective destination, the respective VDB having a first timeflow stored in a respective container. A user can send a request to rewind a VDB. The request identifies timeflow of the VDB and a state of the VDB associated with a timeflow. The database storage system modifies the virtual database to refer to database blocks associated with a snapshot of the VDB associated with the identified timeflow. The database storage system maintains a new timeflow for the modified VDB. The database storage system also allows the virtual database to be refreshed to a state of a source database. The source database can be a database stored in an external system or a virtual database stored within the database storage system.

Abstract: A database storage system allows users to modify the state of a virtual database. The database storage system provides a respective virtual database (VDB) at a respective destination, the respective VDB having a first timeflow stored in a respective container. A user can send a request to rewind a VDB. The request identifies timeflow of the VDB and a state of the VDB associated with a timeflow. The database storage system modifies the virtual database to refer to database blocks associated with a snapshot of the VDB associated with the identified timeflow. The database storage system maintains a new timeflow for the modified VDB. The database storage system also allows the virtual database to be refreshed to a state of a source database. The source database can be a database stored in an external system or a virtual database stored within the database storage system.

Abstract: An application development system allows developers of software system to manage infrastructure resources during the development and testing process. The application development system allows users to define application containers that comprise components including source code, binaries, and virtual databases used for the application. An application container can be associated with policies that control various aspects of the actions taken using the application container including constraints and access control. The application development system enforces the policies for actions taken by users for the application containers. The encapsulation of policies with the application containers allows users of the application containers to take actions including creating virtual databases, provisioning virtual databases, and the like without requiring system administrators to manage resource issues.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.

Abstract: Virtual databases are provisioned using point-in-time copies of a source database. Transaction logs received from the source database are applied to a point-in-time copy of the source database to create recovery milestones comprising database blocks that can be used to provision virtual databases. The recovery milestones are created in advance of receiving a request to provision a virtual database. Each recovery milestone is validated to determine that a consistent database snapshot can be created using the recovery milestone. If a problem is identified that prevents creation of a consistent database snapshot, the problem is fixed before creating the next recovery milestone. In response to receiving a request to provision a virtual database corresponding to a point in time, a recovery milestone is identified and transaction logs applied to the recovery milestone to create a database snapshot corresponding to the requested point in time.

Abstract: Virtual databases are provisioned using point-in-time copies of a source database. Transaction logs received from the source database are applied to a point-in-time copy of the source database to create recovery milestones comprising database blocks that can be used to provision virtual databases. The recovery milestones are created in advance of receiving a request to provision a virtual database. Each recovery milestone is validated to determine that a consistent database snapshot can be created using the recovery milestone. If a problem is identified that prevents creation of a consistent database snapshot, the problem is fixed before creating the next recovery milestone. In response to receiving a request to provision a virtual database corresponding to a point in time, a recovery milestone is identified and transaction logs applied to the recovery milestone to create a database snapshot corresponding to the requested point in time.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.

Abstract: File system backups are performed by copying information describing changes in the file system since a previous point in time. To restore data, a virtual restored file system (VRFS) structure is created corresponding to a snapshot of data copied from the file system that is stored in the backup file system. A client can read the data stored in the backup file system pointed at by the VRFS structure as well as write to the backup file system. Multiple clients can share blocks of data stored on the backup file system via the same VRFS structure or via multiple VRFS structures. If a client writes to a data block pointed at by a VRFS, a copy of the data block is made to which the client makes changes so that the data in the original data blocks is saved for other clients.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.

Abstract: Information from multiple databases is retrieved and stored on a database storage system. Multiple point-in-time copies are obtained for each database. A point-in-time copy retrieves data changed in the database since the retrieval of a previous point-in-time copy. A virtual database (VDB) is created by creating a set of files in the data storage system. Each file in the set of files created for a VDB is linked to the database blocks on the database storage system associated with a point-in-time copy of the source database. The set of files associated with the VDB are mounted on a database server allowing the database server to read from and write to the set of files. Workflows based on VDBs allow various usage scenarios based on databases to be implemented efficiently, for example, testing and development, backup and recovery, and data warehouse building.