Abstract: A method and system for optimizing the execution of database statement is described. Optimization of database statements having non-boolean predicates is disclosed. Also disclosed is the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions.

Abstract: A method and apparatus are provided for accessing ancillary data, and for generating and accessing ancillary data more efficiently. Ancillary data is generated during execution of the operator routine of a primary operator. The ancillary data is stored in a shared content and may be accessed through ancillary operators associated with the primary operator. Metadata is used to define a primary operator and ancillary operators associated with the primary operator. A DBMS, for example, receives a statement that includes a primary and at least one of its ancillary operators, and executes routines that implement the primary operator and the ancillary operator. During execution of the routine the implements the primary operator, ancillary data is generated and stored in shared content. During the execution of the routine that implements the ancillary operator, the ancillary data is retrieved from the shared content and is used.

Abstract: A method and system for associating properties in a computer system is described. An aspect relates to a mechanism for dynamically determining the value of a property for an instance or object, which can override the property defined for the class or object type. Another aspect relates to a mechanism for dynamically changing at run-time the set of properties associated with system structures, such as classes, object types, instances, or objects. Yet another aspect relates to a mechanism that can associate or disassociate an entire set of properties at the same time, rather than having to separately associate or disassociate each property within a set of properties. A further aspect relates to a mechanism for allowing particular instances or objects to explicitly not inherit properties of its familial class or object type.

Abstract: A method and system for optimizing the execution of database statement is described. An aspect is related to providing a framework for the creation, association, and use of optimizer-related functions to calculate the cost of execution plans involving non-native database entities. Examples of these optimizer-related functions include selectivity, statistics, and costs functions. Another aspect is related to the optimization of database statements having non-boolean predicates. Yet another aspect is related to the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions. Optimizer-related functions can also be defined for system-supplied objects and entities.

Abstract: Described herein is a framework for providing statement atomicity for DDL statements. The framework allows the ability to perform, as multiple transactions, the DDL operations specified by a DDL statement. To begin execution of a DDL statement, a DBMS, for example, updates a flag to indicate that DDL operations have commenced. While the flag is set to this state, the DBMS prevents execution of operations that depend on the DDL statement being executed as an atomic unit. If the DDL operations are aborted, the flag is set to a state that indicates that the execution of the DDL operations did not complete, and the DBMS continues to disallow dependent operations that depend on the atomicity of the DDL statement. Because the flag is used to provide statement atomicity, DDL operations may be performed as multiple transactions. For a DML statement, a mechanism described herein preserves the transactional context of a DML statement.

Abstract: A method and system for optimizing the execution of database statements are described. An aspect is directed to the generation of an execution plan for a database statement, wherein the database statement contains a predicate having one or more arguments whose values are not known at the time the execution plan is generated (e.g., at compile time). A feature of this aspect involves passing a description of the argument(s) to the optimizer. An example of such a description includes the argument type of the predicate argument.

Abstract: A method and apparatus for efficiently storing and retrieving data in a database using index-only tables is disclosed. Storing a row of data in a database using index-only tables involves storing in a leaf node an index entry that includes a key value along with all other values in the row of data. If the row of data exceeds a predetermined size, then a portion of the row of data is stored in a user specified overflow area. Retrieving a row of data from an index-only table for a user-supplied key involves identifying a leaf node for the key, and reading a row of data from the index entry and any remaining portion from the overflow area when the row exceeds the predetermined size.

Abstract: A method and apparatus for processing a query in a database system using index types that are not built into the database system are disclosed. Routines for managing an index structure that is not supported by a database system are generated. Data that identifies the routines are submitted to the database system, thereby "registering" the index types with the database system. In response to statements issued to the database system by a client, the database system calls the routines, causing the routines to create an index structure using data from a data container in the database, and to generate data that indicates which data in the data container satisfies a query issued by the client. The routines of the registered index type extend the indexing capabilities of the database systems and one or more such index types can be registered with the database system. The index structure managed by the routines may be maintained within segments of the database, and the segments may be accessed as index-only tables.

Abstract: A method and apparatus for building, maintaining, and using a multi-level index is provided. The multi-level index is accessed using a key. The key is divided into multiple portions referred to as sub-keys. The first level of the multi-level index is built on a first-level sub-key. Each index entry at the first-level is for a particular first-level sub-key value, and either includes sub-entries associated with second-level sub-key values or a reference to a second-level data retrieval structure. All second-level data retrieval structures are built on the portion of the key that has been designated as the second-level sub-key. As the vocabulary of the first-level sub-key becomes exhausted, fewer maintenance operations will have to be performed to maintain the first-level data retrieval structure. This decreases the overhead and increases the concurrency in a database system that uses the multiple-level index.

Abstract: A method and apparatus of operating a display system for displaying data items stored in an associated database. The database stores a display function for each data item class to be also stored in the database therein. When the user selects a data item class, a data item of and a display function associated with the selected data item class are retrieved from the database. The data item is used as an argument of a display function call. The system displays an object using the display data and the data format returned as the result of the display function call. The system may store multiple representations of each data item such as, pictorial, textual and audio representations which may be selected under user control.