Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped field included in a collection of documents. Each untyped field is configured to store one or more scalar data values. The system generates histograms for scalar data values stored in untyped fields. Responsive to receiving a query statement for fetching or updating data value stored in one of the untyped fields, the system assigns a cost to each operator associated with the query statement based on the histogram, compares the costs assigned to the operators, and generates a query execution plan based on the comparison, and query the database using the query execution plan.

Abstract: A distributed database system receives and executes a transaction including a first modification statement describing a first modification operation on a subset of records, a second modification statement describing a second modification operation on the subset of records, and a commit statement. Responsive to executing the first and second modification statements, the system receives a copy of the subset of records from data servers; performs the first modification operation to generate a first modified subset of records; and performs the second modification operation on the first modified subset of records. Responsive to executing the commit statement, the system stores the second modified subset of records in a commit table and causes the subset of records to be updated at the data servers.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: A distributed database system executes transactions on a distributed database. A received transaction includes statements describing modifications of records stored in the distributed database. The distributed database system executes the transaction at a query server by obtaining copies of records corresponding to the statements of the transaction and performing the modifications specified by the statements of the transaction on the record copies. The distributed database system stores the modified record copies at the query server during execution of the transaction. After the transaction has successfully been executed at the query server, the distributed database system attempts to perform a commit process to update the records stored in the distributed database based on the modified record copies.

Abstract: A database system performs queries on fields storing arrays of a database (i.e., array fields) using de-duplication indexes. The system generates de-duplication indexes for array fields. The de-duplication indexes include unique entries for corresponding distinct values stored by the array fields. The system uses the de-duplication indexes to perform efficient queries specifying corresponding array fields. The system may further generate de-duplication indexes corresponding one or more fields storing various types of values. In various embodiments, the system selects an optimal index from various indexes usable to execute a query, such as a de-duplication index and a conventional index.

Abstract: A database system performs queries on fields storing arrays of a database (i.e., array fields) using de-duplication indexes. The system generates de-duplication indexes for array fields. The de-duplication indexes include unique entries for corresponding distinct values stored by the array fields. The system uses the de-duplication indexes to perform efficient queries specifying corresponding array fields. The system may further generate de-duplication indexes corresponding one or more fields storing various types of values. In various embodiments, the system selects an optimal index from various indexes usable to execute a query, such as a de-duplication index and a conventional index.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: A distributed database system executes transactions on a distributed database. A received transaction includes statements describing modifications of records stored in the distributed database. The distributed database system executes the transaction at a query server by obtaining copies of records corresponding to the statements of the transaction and performing the modifications specified by the statements of the transaction on the record copies. The distributed database system stores the modified record copies at the query server during execution of the transaction. After the transaction has successfully been executed at the query server, the distributed database system attempts to perform a commit process to update the records stored in the distributed database based on the modified record copies.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: A database system performs queries on fields storing arrays of a database (i.e., array fields) using de-duplication indexes. The system generates de-duplication indexes for array fields. The de-duplication indexes include unique entries for corresponding distinct values stored by the array fields. The system uses the de-duplication indexes to perform efficient queries specifying corresponding array fields. The system may further generate de-duplication indexes corresponding one or more fields storing various types of values. In various embodiments, the system selects an optimal index from various indexes usable to execute a query, such as a de-duplication index and a conventional index.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: A document-oriented database system generates an optimal query execution plan for database queries on an untyped data field included in a collection of documents. The system generates histograms for multiple types of data stored by the untyped data field and uses the histograms to assign costs to operators usable to execute the database query. The system generates the optimal query execution plan by selecting operators based on the assigned costs. In various embodiments, the untyped data field stores scalars, arrays, and objects.

Abstract: Disclosed is a technique for processing predicates in an iterator function. When an iterator function included in a statement is invoked, one or more predicates included in the statement are obtained. The one or more predicates are applied to a row of data. If applying the one or more predicates results in a match, the row of data is returned. If applying the one or more predicates does not result in a match, a search is performed for another row of data for which application of the one or more predicates results in a match. Also disclosed is a technique for processing predicates in which a statement including an iterator function and one or more predicates is received. A qualification descriptor that describes the one or more predicates and one or more functions that are to be used to evaluate the one or more predicates is created. Then, the iterator function is invoked one or more times, until receiving a done indicator from the iterator function.

Abstract: Disclosed is a mechanism that can be implemented in database systems to support distributed transactions in heterogeneous systems. Once the transaction manager of a database system implements this mechanism, application developers and vendors can integrate new datasources into the transaction manager of the database system. This would simplify the application design and ensure the integrity of data and interactions. The interface and interactions between the transaction manager and external datasources (both structured and non-structured) conform to X/Open XA standards. Also disclosed is a technique to design the system catalogs for organizing the datasources and instances of the new datasources.