Abstract: A method for maintaining cache of database objects using a chain set that includes multiple chains each specifying an ordering of database objects is disclosed. In response to a change of state of a particular database object, a corresponding chain is selected. The selected chain is then locked, the state of the particular database object changed, and then the selected chain is unlocked.

Abstract: Techniques are disclosed for handling database queries from multiple different application versions using a single database. A computer system executing a database management system (DBMS) may receive a database query for a database, where the database query is received from a particular version of an application having a plurality of versions. The database query may specify the particular version. The computer system may then identify catalog tables, where the catalog tables include version information columns storing version access information. The computer system may determine that version access information for the database query indicates that one or more database objects corresponding to the database query are accessible to the particular version of the application.

Abstract: Techniques are disclosed relating to concurrently processing transactions. A computer system may maintain a database table having a plurality of versions. Each of the versions may identify a corresponding portion of the database table that transactions associated with that version are permitted to access. The computer system may receive a first request to perform a first transaction to modify a definition of the database table. The computer system may receive a second request to perform a second transaction to modify data stored in the database table. In response to determining that the first and second transactions are associated with different versions of the plurality of versions, the computer system may concurrently process the first and second transactions.

Abstract: Techniques are disclosed for handling database queries from multiple different application versions using a single database. A computer system executing a database management system (DBMS) may receive a database query for a database, where the database query is received from a particular version of an application having a plurality of versions. The database query may specify the particular version. The computer system may then identify catalog tables, where the catalog tables include version information columns storing version access information. The computer system may determine that version access information for the database query indicates that one or more database objects corresponding to the database query are accessible to the particular version of the application.

Abstract: A method for maintaining cache of database objects using a chain set that includes multiple chains each specifying an ordering of database objects is disclosed. In response to a change of state of a particular database object, a corresponding chain is selected. The selected chain is then locked, the state of the particular database object changed, and then the selected chain is unlocked.

Abstract: Techniques are disclosed relating to concurrently processing transactions. A computer system may maintain a database table having a plurality of versions. Each of the versions may identify a corresponding portion of the database table that transactions associated with that version are permitted to access. The computer system may receive a first request to perform a first transaction to modify a definition of the database table. The computer system may receive a second request to perform a second transaction to modify data stored in the database table. In response to determining that the first and second transactions are associated with different versions of the plurality of versions, the computer system may concurrently process the first and second transactions.

Abstract: There is disclosed a system and method for executing multiple distinct aggregate queries. In an embodiment, the method comprises: providing at least one Counting Bloom Filter for each distinct column of an input data stream; reviewing count values in the at least one Counting Bloom Filter for the existence of duplicates in each distinct column; and if necessary, using a distinct hash operator to remove duplicates from each distinct column of the input data stream, thereby removing the need for replicating the input data stream and minimizing distinct hash operator processing. Also, the use of Counting Bloom Filters for monitoring data streams allow an early duplicate removal of the input stream of data, resulting in savings in computation time and memory resources.

Abstract: For a data processing system having memory for storing a database, a method, a system and a computer program product for directing the data processing system to process a record to be inserted into the database is disclosed. The database includes a plurality of base tables.

Abstract: For a data processing system having memory for storing a database, a method, a system and a computer program product for directing the data processing system to process a record to be inserted into the database is disclosed. The database includes a plurality of base tables.

Abstract: There is disclosed a system and method for executing multiple distinct aggregate queries. In an embodiment, the method comprises: providing at least one Counting Bloom Filter for each distinct column of an input data stream; reviewing count values in the at least one Counting Bloom Filter for the existence of duplicates in each distinct column; and if necessary, using a distinct hash operator to remove duplicates from each distinct column of the input data stream, thereby removing the need for replicating the input data stream and minimizing distinct hash operator processing. Also, the use of Counting Bloom Filters for monitoring data streams allow an early duplicate removal of the input stream of data, resulting in savings in computation time and memory resources.

Abstract: For a data processing system having memory for storing a database, a method, a system and a computer program product for directing the data processing system to process a record to be inserted into the database is disclosed. The database includes a plurality of base tables.

Abstract: For a data processing system having memory for storing a database, a method, a system and a computer program product for directing the data processing system to process a record to be inserted into the database is disclosed. The database includes a plurality of base tables.

Abstract: A computer system identifies a predicate in a computer language containing constant expressions as vacuous. The system identifies distinct variables contained in the predicate and represents the predicate by a set of bounding rectangles. The bounding rectangles are represented in a space having a number of dimensions equal to the number of variables. There are finite limits on dimensions of a bounding rectangle which represent the relationship between the variables in the predicate and the constant expressions in the predicate. The predicate is identified as vacuously FALSE where the set of bounding rectangles is empty.

Abstract: A method, apparatus, and article of manufacture for an intelligent compiler. A query is executed in a computer to retrieve data from a relational database stored on a data storage device. The query contains a procedural function. The query is compiled to generate an internal representation of the procedural function. Then, the execution of the procedural function is optimized using the generated internal representation.

Abstract: A method, apparatus, and article of manufacture for an intelligent compiler. A query is executed in a computer to retrieve data from a relational database stored on a data storage device. One or more scripting language statements are compiled to generate an internal representation. Then, the execution of the scripting language statements is optimized using the generated internal representation.

Abstract: The system, method, and program of this invention avoids potential write/write conflicts and read/write conflicts when a subcomponent of a composite object (e.g., an ADT) is mutated. The embodiments of this invention define a copy semantic for the mutation function. In one embodiment, a copy function is inserted prior to any mutation function. In a another embodiment, a global compile-time analysis is performed to determine if a write/write or read/write conflict exists; and to eliminate redundant copy constructors if a conflict does exist. In a preferred embodiment, only a local analysis is performed during the parsing phase, thereby avoiding a global compile-time analysis. A mutation safe flag is associated with each parse tree node. A read target leaf parse tree node is set to false while non-leaf parse tree nodes (functions) derive their value from an incoming node, except that constructors and copy constructor functions are always true. Whether or not a copy is made of the composite object (i.e.