Abstract: Locks placed on corresponding objects held in a plurality of databases located at different nodes in a network during replication are released in accordance with fairness criteria. Propagation delays are determined between a transaction initiating node and one or more other nodes in the network. An object is locked during a transaction being executed at the transaction initiating node. Corresponding objects are locked at one or more other nodes in the network that are manipulated as a result of the replication Upon determining that the object locks should be released, the propagation delays are used to determine when to release the object locks so that all of the object locks at the one or more other nodes are released in accordance with the fairness criteria.

Abstract: A method of performing transactions in accordance with fairness criteria is provided wherein one of a plurality of entities initiates a transaction on an object at a database. The steps or operations of the initiated transaction are immediately processed up to the transaction ownership step. Propagation delays are determined between the database and at least some of the other entities that are capable of initiating transactions to the database. The propagation delays and a fairness criteria is used to determine the fair propagation delay period. Upon determining that the fair propagation delay period has been exceeded, it is detecting whether any of the other entities initiated a transaction on the same object during the fair propagation delay time period. If not, then the transaction initiating entity performs the transaction ownership step on the initiated transaction.

Abstract: A replication system that includes an asynchronous replication mode and a synchronous replication mode replicates data associated with a plurality of transactions. The replication system includes one or more target nodes connected via communication media in a topology. Each target node includes a database and a plurality of appliers allocated thereto. Each transaction has one or more transaction steps or operations. A first set of transaction steps or operations are allocated to the plurality of appliers on an object-by-object basis when the replication system operates in asynchronous replication mode. A second set of transaction steps or operations are allocated to the plurality of appliers on a transaction-by-transaction basis when the replication system operates in synchronous replication mode.

Abstract: A method is provided for replicating transaction data from a source database to a target database wherein the transaction data is communicated from a change queue associated with the source database to the target database. An initial path is provided between the change queue and the target database for transaction data to flow. The initial path has a maximum transaction load capacity. It is then detected whether the current transaction load is close or equal to the maximum transaction load capacity of the initial path. If so, another path is provided between the change queue and the target database.

Abstract: A method is provided for using at least one response bubble on a response form to indicate one or more responses. The response form has a key definition area that includes one or more response bubbles corresponding to one or more intended responses, and a response area that includes one or more response bubbles for indicating intended responses. A response form is completed by defining an unambiguous symbology of one or more marks by completing the key definition area, and filling in the response area using the defined unambiguous symbology. The response form is then electronically imaged. The unambiguous symbology is then automatically interpreted from the key definition area of the response form. The indicated intended responses of the one or more response bubbles of the completed response form are automatically interpreted using the interpreted unambiguous symbology, and the electronically imaged completed response form.

Abstract: A method is provided for replicating transaction data from a source database to a target database wherein the transaction data is communicated from a change queue associated with the source database to the target database. An initial path is provided between the change queue and the target database for transaction data to flow. The initial path has a maximum transaction load capacity. It is then detected whether the current transaction load is close or equal to the maximum transaction load capacity of the initial path. If so, another path is provided between the change queue and the target database. Also, a method is provided of replicating transaction data from a source database to a target database wherein an associated with the target database has a maximum transaction threshold limit. The applier normally posts transaction data to the target database only upon receipt of a commit step or operation associated with respective transaction data.

Abstract: A method is provided for resolving collisions in a database replication system. The system includes a source database and a target database, wherein changes made at the source database are replicated to the target database. Each database has one or more tables, and at least one of the tables has multiple constraints. A collision is detected during data replication as a result of one of the tables having multiple constraints. One constraint that contributes to the collision is identified. The constraint that contributes to the collision is relaxed, or the cause of the constraint that contributes to the collision is removed. This process is repeated for all additional constraints that contribute to the collision. In this manner, the collision is resolved.

Abstract: Image data of a response form is processed. The response form has a plurality of response bubbles, including at least one filled and at least one unfilled response bubble. One or more baseline response bubble attributes for unfilled response bubbles are provided in a memory. Image data of a response form is processed to determine one or more response bubbles that are unfilled. One or more actual response bubble attributes of the one or more unfilled response bubbles is then calculated. A difference metric value is then calculated by comparing the one or more baseline response bubble attributes to the one or more actual response bubble attributes. The one or more baseline response bubble attributes are reset to a new set of one or more baseline response bubble attributes if the difference metric value exceeds a predetermined threshold. The one or more baseline response bubble attributes are maintained at their present value if the difference metric value does not exceed the predetermined threshold.

Abstract: An automated method is provided of replicating a locking protocol in a database environment for performing I/O operations wherein the database environment includes a plurality of databases. A locking protocol is performed that includes one or more explicit locking operations on objects in a first database of the database environment. The one or more explicit locking operations are replicated in one or more other databases in the database environment. At least some of the explicit locking operations are performed asynchronously with respect to the explicit locking operations performed in the first database. I/O operations are performed at the first database of the database environment that are associated with the one or more explicit locking operations implemented in the first database.

Abstract: A method is provided for loading data from a source database to a target database that includes at least one table. Prior to loading the data from the source database into the target database, at least one referential integrity constraint and/or at least one consistency requirement regarding the data is automatically identified. A subset of the data that satisfies the at least one referential integrity constraint and/or consistency requirement is then automatically identified. The identified subset of the data is then loaded into the target database as a unit of work.

Abstract: A target database is synchronized with a source database and the source database is replicated to the target database in a database replication system. The source database is on-line during the synchronization. The source database is located at a first node of the system, and the target database is located at a second node of the system. Changes in the source database are replicated to the target database by sending a replication stream from the first node to the second node. Successive blocks of data are sent from the first node to the target database to synchronize or resynchronize the target database with the source database. Each block of data includes one or more rows of data. The successively sent blocks of data define a loading stream. The successively sent blocks of data are posted into the target database when the replication stream is occurring slower than the loading stream. Synchronization or resynchronization thereby occurs simultaneously with replication.

Abstract: Response bubbles on a scannable form are provided that allow a user to mark the bubbles in a manner that signifies that the user wishes to have a response disregarded.

Abstract: A method is provided for replicating transaction data from a source database to a target database wherein the transaction data is communicated from a change queue associated with the source database to the target database. An initial path is provided between the change queue and the target database for transaction data to flow. The initial path has a maximum transaction load capacity. It is then detected whether the current transaction load is close or equal to the maximum transaction load capacity of the initial path. If so, another path is provided between the change queue and the target database. Also, a method is provided of replicating transaction data from a source database to a target database wherein an associated with the target database has a maximum transaction threshold limit. The applier normally posts transaction data to the target database only upon receipt of a commit step or operation associated with respective transaction data.

Abstract: A method is provided for processing base level data of a change queue that is not serialized at the logical level. The base level change queue data is transaction data previously posted to a source database. A logical replication engine is provided to replicate and post the change queue data to a target database in the order that the transaction data is stored in the change queue. Upon detection in the logical replication engine of change queue data that is not serialized at the logical level, the change queue data is reserialized at the logical level before the logical replication engine applies the change queue data to the target database. The change queue data that is not serialized at the logical level may be posted to the target database using asynchronous database access.

Abstract: A target database is synchronized with a source database and the source database is replicated to the target database in a database replication system. The source database is on-line during the synchronization. The source database is located at a first node of the system, and the target database is located at a second node of the system. Changes in the source database are replicated to the target database by sending a replication stream from the first node to the second node. Successive blocks of data are sent from the first node to the target database to synchronize or resynchronize the target database with the source database. Each block of data includes one or more rows of data. The successively sent blocks of data are inserted into the replication stream at a point when the respective blocks of data are current or consistent in the source database, and the replication stream is posted to the target database. Synchronization or resynchronization thereby occurs simultaneously with replication.

Abstract: During replication of transaction data from a source database to a target database via a change queue associated with the source database, one or more multiple paths are provided between the change queue and the target database. The one or more multiple paths cause at least some of the transaction data to become unserialized. At least some of the unserialized data is reserialized prior to or upon applying the originally unserialized transaction data to the target database. If the current transaction load is close or equal to the maximum transaction load capacity of a path between the change queue and the target database, another path is provided. If the maximum transaction threshold limit of an applier associated with the target database has been reached, open transactions may be prematurely committed.

Abstract: An automated method is provided of replicating a locking protocol in a database environment for performing I/O operations wherein the database environment includes a plurality of databases. A locking protocol is performed that includes one or more explicit locking operations on objects in a first database of the database environment. The one or more explicit locking operations are replicated in one or more other databases in the database environment. At least some of the explicit locking operations are performed asynchronously with respect to the explicit locking operations performed in the first database. I/O operations are performed at the first database of the database environment that are associated with the one or more explicit locking operations implemented in the first database.

Abstract: Data associated with a plurality of transactions in a data replication system including first and second nodes connected via communication media in a topology is replicated. Each node includes a database and a replication engine which performs data replication functions between the first and second nodes. Each transaction is one or more transaction steps or transaction operations. One or more initial transaction steps or operations of a transaction are sent from an input device to a first node. The one or more initial transaction steps or operations of the transaction are sent to the second node via the replication engine at the first node. If a communication failure is detected between the input device and the first node, the input device sends the remaining transaction steps or operations to the second node.

Abstract: A method is provided for loading data from a source database to a target database that includes at least one table. Prior to loading the data from the source database into the target database, at least one referential integrity constraint and/or at least one consistency requirement regarding the data is automatically identified. A subset of the data that satisfies the at least one referential integrity constraint and/or consistency requirement is then automatically identified. The identified subset of the data is then loaded into the target database as a unit of work.

Abstract: A replication system that includes an asynchronous replication mode and a synchronous replication mode replicates data associated with a plurality of transactions. The replication system includes one or more target nodes connected via communication media in a topology. Each target node includes a database and a plurality of appliers allocated thereto. Each transaction has one or more transaction steps or operations. A first set of transaction steps or operations are allocated to the plurality of appliers on an object-by-object basis when the replication system operates in asynchronous replication mode. A second set of transaction steps or operations are allocated to the plurality of appliers on a transaction-by-transaction basis when the replication system operates in synchronous replication mode.