International Business Machines Corporation

Margaret Ann Dong

James Willis Pickel

Curt Lee Cotner

William Robert Bireley

Paul Miller Bird

Tammie Dang

Hugh J Smith

Shivram Ganduri

Georgia Carroll Fuller

Frankie K Sun

Michelle D Lam

Richard K Treiber

Sigitas Bigelis

Kelvin Ho

Continuously blocking query result data for a remote query is provided. Included is: creating a first connection, using a communications network, between a database server and a client. At least one secondary connection is created, using the communications network, between the database server and the client, based on the database server supporting a continuous block fetch protocol. Using the at least one secondary connection, the database server receives at least one cursor-based fetch query. The database server generates continuous blocks of result data, based on the received at least one cursor-based fetch query and sends to the client, using the at least one secondary connection, the continuous blocks of result data.

Continuously blocking query result data for a remote query

A method and system for efficient allocation of memory in database retrieval employs a technique which allocates a memory portion of a first size which may or may not be smaller than a data item to be retrieved from the database (such as a column which may be of indeterminate length). In that circumstance, a first FETCH, for example, an SQL FETCH, is followed by a new syntactical instruction, a FETCH CONTINUE, until all of the data item is retrieved. The FETCH CONTINUE may involve allocating memory portions of similar or different sizes to accommodate additional fetched portions, and may involve varying numbers of fetches.

Method and system for efficient retrieval of data of large or unknown length by a native application program

Provided are a system and program for accessing data in a distributed database environment. A client program receives multiple requests for data from a database object satisfying specified search predicates from an application program. Each request includes a request for at least one row from the table. The client program transfers a database command and a rowset parameter indicating a maximum number of rows to return to a server program over a network if the requested row is not maintained by the client program. A data block is generated with the server program including rows from the database object satisfying the search predicates in response to the database command. The rows included in the data block do not exceed the rowset parameter. The server program transfers the data block to the client program. In turn, the client program returns at least one requested row from the received data block in response to one request for the at least one row of data from the application program.

System and program for implementing scrollable cursors in a distributed database system

In a system for avoiding section collision for application server requests over a single database connection, the database server assigns query identifiers to each instance of the same cursor opened for the same processing level within an application, allowing multiple instances of the same cursor to be processed in parallel without section collision. The application server assigns a command source identifier to each statement sent over a single database connection to uniquely identify the application source of the statement. This applies for multiples of the same statement sent by different application sources within the same application, for a single statement containing multiple application sources, and for multiple statements from different applications multiplexed over a single database connection. These statements can be processed separately from and in parallel with the each other without section collision.

Computer-readable medium to multiplex multiple application server requests over a single database connection

Provided is a method for accessing data in a distributed database environment. A client program receives multiple requests for data from a database object satisfying specified search predicates from an application program. Each request includes a request for at least one row from the table. The client program transfers a database command and a rowset parameter indicating a maximum number of rows to return to a server program over a network if the requested row is not maintained by the client program. A data block is generated with the server program including rows from the database object satisfying the search predicates in response to the database command. The rows included in the data block do not exceed the rowset parameter. The server program transfers the data block to the client program. In turn, the client program returns at least one requested row from the received data block in response to one request for the at least one row of data from the application program.

Method implementing scrollable cursors in a distributed database system

In a method for avoiding section collision for application server requests over a single database connection, the database server assigns query identifiers to each instance of the same cursor opened for the same processing level within an application, allowing multiple instances of the same cursor to be processed in parallel without section collision. The application server assigns a command source identifier to each statement sent over a single database connection to uniquely identify the application source of the statement. This applies for multiples of the same statement sent by different application sources within the same application, for a single statement containing multiple application sources, and for multiple statements from different applications multiplexed over a single database connection. These statements can be processed separately from and in parallel with the each other without section collision.

Method and mechanism to multiplex multiple application server requests over a single database connection

Provided is a method, system, and program for accessing data in a distributed database environment. A client program receives multiple requests for data from a database object satisfying specified search predicates from an application program. Each request includes a request for at least one row from the table. The client program transfers a database command and a rowset parameter indicating a maximum number of rows to return to a server program over a network if the requested row is not maintained by the client program. A data block is generated with the server program including rows from the database object satisfying the search predicates in response to the database command. The rows included in the data block do not exceed the rowset parameter. The server program transfers the data block to the client program. In turn, the client program returns at least one requested row from the received data block in response to one request for the at least one row of data from the application program.

Method, system, and program for implementing scrollable cursors in a distributed database system

The present invention discloses a method, apparatus, and article of manufacture for transmitting data having non-standard data types between computers. A query is executed to retrieve data from a database. The database comprises data having standard data types and data having non-standard data types and is stored on a data storage device connected to a server computer. At the server computer, data having standard data types, small non-standard data types, and large non-standard data types is retrieved. An answer set is generated that comprises data having standard data types, small non-standard data types, and one or more placeholders representing data having the large non-standard data types. The generated answer set is transmitted to a client computer. After transmitting the generated answer set, data represented by each placeholder in the answer set is transmitted to the client computer.

Externalizing very large objects in a relational database client/server environment

The present invention discloses a method, apparatus, and article of manufacture for transmitting data having non-standard data types between computers. A query is executed to retrieve data from a database. The database comprises data having standard data types and data having non-standard data types and is stored on a data storage device connected to a server computer. At the server computer, data having standard and non-standard data types is retrieved. An answer set is generated that comprises data having standard data types and one or more placeholders, wherein each placeholder represents data having a non-standard data type. The generated answer set is transmitted to a client computer. After transmitting the generated answer set, data represented by each placeholder in the answer set is transmitted to the client computer.

A method for expanding and contracting a resource pool dynamically, i.e. in response to demand for the resources, is disclosed. Resources are allocated for use from a single master pool 22. The overall pool of available resources is expanded by creating an extension pool and adding its resources to the master pool. The master pool can theoretically be expanded to the limits of the number of resources available in the system. To contract the pool dynamically, first one of the extension pools is selected to be freed (FREE.sub.-- POOL 66). Those resources owned by the freed pool but still in the master pool (i.e., not in use) are moved to the extension pool, preventing their reuse. Resources in use which are owned by the freed pool are labeled by changing their home address 52 so that they will be returned to the extension pool instead of to the master pool. Once all such resources have been returned to the freed extension pool it is deleted, thereby contracting the overall pool of resources. Pseudocode implementations of the procedures for manipulating storage buffers and buffer pools are included.

Growing community of inventors

San Jose, CA, United States of America

Margaret Ann Dong