Abstract: A first computer establishes a logical connection to a second computer for requesting and/or receiving data from a database. A logical connection is independent of the underlying physical network connection used to connect to the database. A context identifier is stored by both computers to enable the context of a logical connection to be persisted between switches from one physical network connection to another within the logical connection thus enabling database transfers to be continued on a second physical network connection when a failure in a first physical network connection occurs.

Abstract: Systems and methods are described that establish and maintain a virtual session between a client and one or more database servers. A database server establishes a first session with a client wherein establishing the virtual session with the client comprises associating a virtual session identifier (ID) with the first session, generates state information in association with the first session, and stores the state information in a repository in association with the virtual session ID. After the first session fails, a same or different database server establishes a second session with the client wherein establishing the second session with the client comprises receiving the virtual session ID from the client, accesses the state information that was stored in the repository in association with the virtual session ID, and associates the state information with the second session.

Abstract: Systems and methods are described that facilitate idempotent execution of commands generated by a client for execution by a database server. Each command transmitted to the server includes a command ID generated by the client. The server attempts to execute each command and subsequently stores the command ID associated therewith in a repository along with an indication of whether the command executed successfully. When a new command is received by the server, it determines if the command ID associated therewith has already been stored in the repository. If the command ID associated with the new command has not already been stored in the repository, then the server executes the new command. If the command ID associated with the new command has already been stored in the repository and a previously-received command associated with the command ID has been executed successfully, then the server will not execute the new command.

Abstract: Aspects of the subject matter described herein relate to extending types hosted in a database to other platforms. In aspects, a database may store objects according to a one type system while an application accessing the database may store objects according to another type system. To allow the application to understand the types, a mapping mechanism may be employed that maps from the types of type system of the database to types of a type system of the application. The mapping mechanism may utilize metadata associated with the data in mapping between types. In conjunction with mapping a source type to a target type, a target object may be instantiated and populated with properties of a source object of the source type.

Abstract: A first computer establishes a logical connection to a second computer for requesting and/or receiving data from a database. A logical connection is independent of the underlying physical network connection used to connect to the database. A context identifier is stored by both computers to enable the context of a logical connection to be persisted between switches from one physical network connection to another within the logical connection thus enabling database transfers to be continued on a second physical network connection when a failure in a first physical network connection occurs.

Abstract: A data transfer is received and processed out of order based on contextual information provided by the sending computer. Individual packets within a data transfer are marked as requiring in order processing while the remaining packets of the data transfer are processed out of order. The packets may be labeled with a sequential identifier to enable the receiving computer to determine the proper ordering of packets that require in order processing.

Abstract: A first computer utilizes a logical connection with a second computer. The logical connection comprises multiple physical network connections using multiple physical network devices on the first computer. Two or more of the physical network devices of a logical connection are used to transfer packets of a single data transfer such as a database request or response. A logical connection can include a single physical network device on the second computer creating a one-to-many logical connection or may also include multiple physical network devices on the second computer creating a many-to-many logical connection.

Abstract: Aspects of the subject matter described herein relate to database access. In aspects, a request for access to a database is received at a node of a database cluster. Also received at the node is an intent associated with the request. If the intent is to potentially write to the database, a primary instance of the database services the request. If the intent is to read from but not write to the database, an identifier of a secondary instance of the database is sent to the requestor for use in accessing the database.

Abstract: Aspects of the subject matter described herein relate to extending types hosted in a database to other platforms. In aspects, a database may store objects according to a one type system while an application accessing the database may store objects according to another type system. To allow the application to understand the types, a mapping mechanism may be employed that maps from the types of type system of the database to types of a type system of the application. The mapping mechanism may utilize metadata associated with the data in mapping between types. In conjunction with mapping a source type to a target type, a target object may be instantiated and populated with properties of a source object of the source type.

Abstract: Systems and methods are provided, wherein the method includes retrieving and/or storing one or more data types representative of a selected date and/or time value from a server to a client in a server/client SQL environment using a selected wire format. Another aspect provides apparatus including a SQL server, a SQL client operationally coupled to the server, and means to transmit the selected time/date data types between the server and the client according to a selected wire format. In an illustrative implementation, the wire format translates the date/time data into a binary format.

Abstract: Systems and methodologies that enhance a Tabular Data Stream (TDS) protocol by enabling efficient transmission of a row(s) with null columns(s). An identification component employs a bit map that can be positioned at beginning of a row, to indicate to the receiving side (e.g., a client) columns that are to be sent. Accordingly, by distinguishing columns that are null from columns that are not null—followed by sending columns that are not null—transmission resources can be effectively employed.