Browse Prior Art Database

Partial Native SQLDA for SQLJRA Remote Protocol

IP.com Disclosure Number: IPCOM000109719D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Jordan, LE: AUTHOR [+4]

Abstract

Remote Data Service is a set of functions for OS/2* Extended Edition (EE) that allowed users to access databases not only on their local workstations but also on remote workstations. A private communication protocol (SQLJRA Remote Protocol) was implemented to Extended Services 1.0 to access relational database remotely. One of the features in the SQLJRA Remote Protocol to improve performance is the Record Blocking. With Record Blocking, the server can send multiple data rows in one communication buffer. The client will then retrieve one row at a time from the Communication buffer and pass it to the application program. Communication overhead can be reduced significantly. A SQLDA is a control block structure that describes the data for a data row in a SQL table and is used on requests to the Database Manager.

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This is the abbreviated version, containing approximately 52% of the total text.

Partial Native SQLDA for SQLJRA Remote Protocol

       Remote Data Service is a set of functions for OS/2*
Extended Edition (EE) that allowed users to access databases not only
on their local workstations but also on remote workstations.  A
private communication protocol (SQLJRA Remote Protocol) was
implemented to Extended Services 1.0 to access relational database
remotely.  One of the features in the SQLJRA Remote Protocol to
improve performance is the Record Blocking.  With Record Blocking,
the server can send multiple data rows in one communication buffer.
The client will then retrieve one row at a time from the
Communication buffer and pass it to the application program.
Communication overhead can be reduced significantly.  A SQLDA is a
control block structure that describes the data for a data row in a
SQL table and is used on requests to the Database Manager.  A native
SQLDA is one that contains the EXACT description of that data.  Since
a user is allowed to change his output SQLDA for fetches, Data Base
Manager (DBM) needs to have a native SQLDA in order to hold the data
rows during record blocking.

      In EE 1.3 implementation, Data Base Manager (DBM) allocated a
full native SQLDA for record blocking.  Data Base Manager (DBM)
allocated memory space for the data area in each SQLVAR in the native
SQLDA.  The client will get data from the communication buffer and
put it into the data area.  After the client put all data into the
native SQLDA, it will invoke the translation routine to translate
data in the native SQLDA into the user SQLDA.  Assuming that the
SQLLEN for each SQLVAR is 1,000, the data types are VARCHAR, and
there are two SQLVARs.  The total memory space needed is 4,300 bytes.
The formula to calculate the memory space is as fol...