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 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 handling within a database system data items that are associated with data types whose native structure is not known to the database system. The data items are stored within the database system in their native structure, even though it is not understood by the database system. To store the data items, the database system calls a pickling routine that is provided by the user, or by the runtime subsystem of the programming environment that is native to the data item. To retrieve the routine from storage, the database system calls an unpickling routine, also provided by the user or the appropriate runtime subsystem. Because the database maintains the data items in their native format, no conversions are required as the data items are passed between the database system and external routines that manipulate the data items.

Abstract: A method and apparatus are provided for handling within a database system data items that are associated with data types whose native structure is not known to the database system. The data items are stored within the database system in their native structure, even though it is not understood by the database system. To store the data items, the database system calls a pickling routine that is provided by the user, or by the runtime subsystem of the programming environment that is native to the data item. To retrieve the routine from storage, the database system calls an unpickling routine, also provided by the user or the appropriate runtime subsystem. Because the database maintains the data items in their native format, no conversions are required as the data items are passed between the database system and external routines that manipulate the data items. Techniques are also provided for declaring attributes of the data item that can be accessed within the database system.

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: A method and apparatus are provided for handling within a database system data items that are associated with data types whose native structure is not known to the database system. The data items are stored within the database system in their native structure, even though it is not understood by the database system. To store the data items, the database system calls a pickling routine that is provided by the user, or by the runtime subsystem of the programming environment that is native to the data item. To retrieve the routine from storage, the database system calls an unpickling routine, also provided by the user or the appropriate runtime subsystem. Because the database maintains the data items in their native format, no conversions are required as the data items are passed between the database system and external routines that manipulate the data items. Techniques are also provided for declaring attributes of the data item that can be accessed within the database system.

Abstract: A mechanism is described for processing requests to specify operations to database objects. A request to perform an action on a set of multiple objects is received by a database system. The request includes references to each object in the set, each reference indicating a table where the respective object resides. The reference is used to locate the object, and once located, the action is performed on the object. The reference may indicate a table using a unique table id not used in any of a plurality of databases to identify a table. The action request may be to modify the object, the references may include references to objects that reside in different database systems.

Abstract: A method and apparatus for generating references to a set of objects which reside in a plurality databases is described. Each object is associated with a table from a plurality of tables that are contained in the plurality of databases. An object id is associated with each object; the object id uniquely identifies the object relative to the objects in the set of objects. A table id is associated with each table; the table id uniquely identifies the table relative to tables in the plurality of tables. A table containing an object is located based on the table id associated with the table, and the object is located in the table based on the object id associated with the object. A table mapping is generated. The table mapping maps a set of tables to databases associated with the set of tables. The set of tables are from the plurality of tables. References to objects from the set of object are generated. Each reference comprises data that identifies an object.

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: An apparatus and process for storing representations of information objects having null values in a database are disclosed. A null object is established in memory associated with an information-bearing object. The null object has an attribute null value corresponding to each data-bearing attribute of the information-bearing object. Each attribute null value is set to a value indicating whether the corresponding attribute of the information-bearing object is null, not null, or not capable of having a null value. The null object also has an atomic null value that indicates whether the entire information-bearing object is null. When the information-bearing object is to be accessed, the null object is first accessed to determine whether the entire information-bearing object or any attributes thereof are null. Accordingly, unnecessary retrieval and manipulation of the information-bearing object is avoided.

Abstract: An apparatus and process for storing information objects in a database are disclosed. An information object, instantiated according to an abstract data type having a plurality of attributes, is pickled into an image that contains all values stored in the object in a linearized representation. In one embodiment, the entire image is stored in a single column of a table of the database. In another embodiment, each portion of the image associated with one of the attributes is stored in a separate column of the database table.

Abstract: A method and apparatus for presenting and modifying data from a set of tables in a database is provided. A view that is defined is based on a set of one or more tables that may include relational tables or object tables. The view defines a presentation of data from the one or more tables as a set of objects that reside in the database. Data is read from the one or more rows of the tables based on the view, and is presented as a set of objects that reside in the database. An object id that is based on data from the one or more rows is generated and associated with each object presented. The view may specify which columns from the one or more tables contain values used to generate the object ids. A trigger may associated with the view. The set of objects presented may be presented as objects having an attribute that is a column object. Column objects include user specified object types, collection objects (e.g. nested tables and variable arrays), or references to objects.

Abstract: The present invention pertains to an apparatus and process for storing information object collections in a database. Examples of such object collections are nested tables and variable length arrays. In an embodiment, the invention provides mechanisms and methods for storing nested tables in either a base table of a database, or an index-organized table. In one embodiment, mechanisms and methods are provided for storing variable length arrays into a table column, as a large object ("LOB"), or as an index-organized table. The invention also provides methods and mechanisms for accessing data from these storage mediums.

Abstract: A method and system for performing operations on large objects (LOBs) in a database system are provided. A server receives from a client a command that identifies a row of a table. The table includes a LOB column that contains LOBs. The server responds to the command by sending the client a first set of data from the row. The first set of data includes a locator for a LOB that belongs in the LOB column of the row. The locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB. The server receives from the client a request to perform an operation on the LOB. The request passes the locator for the LOB to a routine provided by the server. The server performs the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.

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.