Abstract: An improved system and method for loading records into a partitioned database table is provided. A translation of records may be generated from a set of source partitions to a set of target partitions by generating a bipartite graph, determining a maximal matching using dynamic programming for a chain of nodes remaining in the bipartite graph after removing singleton edges, and generating a maximal matching after adding back the singleton edges for translation of records from the set of source partitions to the set of target partitions. The partition translation may be executed by traversing from top to bottom the set of source partitions and the set of target partitions in record key order to generate an optimal sequence of operations to transfer the records from the set of source partitions to the set of target partitions.

Abstract: Methods and apparatuses are provided for dynamically reorganizing the data within a replicated database system. One method, for example, includes performing a split operation across a plurality of replicated databases with regard to an existing partition therein, wherein the existing partition comprises a plurality of data records and the two new partitions each include at least a portion of the plurality of data records, and allowing at least one type of access to the plurality of data records during the split operation.

Abstract: An improved system and method for writing data dependent upon multiple reads in a distributed database is provided. A client may read several data records and may then send a request to a database server to perform a transaction to write a data record dependent upon multiple data records read. A database server may receive the request specifying a transaction to write a data record dependent upon multiple data records read and may perform the transaction by latching a master data record to be written and validating the data records the write depends upon. The multiple data records upon which the write depends may be validated by verifying the multiple data records are current versions of the data records stored in the distributed database. Data intensive applications may use this transaction type in large scale distributed database systems to provide stronger consistency without significantly degrading performance and scalability.

Abstract: An improved system and method for loading records into a partitioned database table is provided. A translation of records may be generated from a set of source partitions to a set of target partitions by generating a bipartite graph, determining a maximal matching using dynamic programming for a chain of nodes remaining in the bipartite graph after removing singleton edges, and generating a maximal matching after adding back the singleton edges for translation of records from the set of source partitions to the set of target partitions. The partition translation may be executed by traversing from top to bottom the set of source partitions and the set of target partitions in record key order to generate an optimal sequence of operations to transfer the records from the set of source partitions to the set of target partitions.

Abstract: An improved system and method for writing data dependent upon multiple reads in a distributed database is provided. A client may read several data records and may then send a request to a database server to perform a transaction to write a data record dependent upon multiple data records read. A database server may receive the request specifying a transaction to write a data record dependent upon multiple data records read and may perform the transaction by latching a master data record to be written and validating the data records the write depends upon. The multiple data records upon which the write depends may be validated by verifying the multiple data records are current versions of the data records stored in the distributed database. Data intensive applications may use this transaction type in large scale distributed database systems to provide stronger consistency without significantly degrading performance and scalability.

Abstract: An improved system and method for asynchronous update of indexes in a distributed database is provided. A database server may receive the request to update the data and may update the data in a primary data table of the distributed database. An asynchronous index update of the indexes may be initiated at the time a record is updated in a data table and then control may be returned to a client to perform another data update. An activity cache may be provided for caching the records updated by a client so that when the client requests a subsequent read, the updated records may be available in the activity cache to support the various guarantees for reading the data. Advantageously, the asynchronous index update scheme may provide increased performance and more scalability while efficiently maintaining indexes over database tables in a large scale, replicated, distributed database.

Abstract: An improved system and method for parallel retrieval of data from a distributed database is provided. A parallel interface may be provided for use by a cluster of client machine for parallel retrieval of partial results from parallel execution of a database query by a cluster of database servers storing a distributed database. A query interface may be augmented for inputting a database query and specifying the number of instances of parallel retrieval of results from query execution. To do so, a commercial query language may be augmented for sending a query request that may include a parameter specifying the database query and an additional parameter specifying the desired retrieval parallelism. The augmented query interface may return a list of retrieval point addresses for retrieving the partial results assigned to each of the retrieval point addresses from parallel execution of the database query.

Abstract: Methods and apparatuses are provided for dynamically reorganizing the data within a replicated database system. One method, for example, includes performing a split operation across a plurality of replicated databases with regard to an existing partition therein, wherein the existing partition comprises a plurality of data records and the two new partitions each include at least a portion of the plurality of data records, and allowing at least one type of access to the plurality of data records during the split operation.

Abstract: A system and method for generating and administering classroom exercises to a student. One or more root questions is generated, where each root question has a stem, a plurality of right answers, and a plurality of wrong answers. A multiple-choice question instance is created by combining the stem with a set of answer choices that are created from one of the right answers and one or more of the wrong answers. The questions are administered to a student. Preferably, the sets of questions based on the same root questions are administered one or more times to the student—e.g., a student may be required to work three sets of question instances based on the same set of root questions, or may be required to continue working new sets of question instances until all of the questions in one set are answered correctly.

Abstract: A system and method for generating and administering classroom exercises to a student. One or more root questions is generated, where each root question has a stem, a plurality of right answers, and a plurality of wrong answers. A multiple-choice question instance is created by combining the stem with a set of answer choices that are created from one of the right answers and one or more of the wrong answers. The questions are administered to a student. Preferably, the sets of questions based on the same root questions are administered one or more times to the student—e.g., a student may be required to work three sets of question instances based on the same set of root questions, or may be required to continue working new sets of question instances until all of the questions in one set are answered correctly.