Browse Prior Art Database

Allocation of Equivalent Communication Buffer Sizes in SQLJRA Remote Protocol

IP.com Disclosure Number: IPCOM000103570D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 3 page(s) / 95K

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) will be implemented in OS/2 ES 1.0 to access relational database remotely.

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Allocation of Equivalent Communication Buffer Sizes in 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) will be implemented in OS/2
ES 1.0 to access relational database remotely.

      All Database Manager commands, replies, and data are received
in the client's or server's communication buffer.  The size of this
buffer is a configurable parameter.  This parameter is configurable
on both client and server workstations.  When a remote connection
request is generated, the client allocates the communication buffer
with a size equal to the requestor I/O block size (RQRIOBLK)
parameter.  A similar process takes place on the database server
(SVRIOBLK).  These buffers are used to send and receive data while a
connection is active.

      The following is an example of an open-cursor operation.
(1) The client workstation will will place the appropriate command
data in its communication buffer (4K for this example) and send it to
the server.  The first two bytes of the buffer will contain the
length of the total amount of data that which will be sent to the
server.
(2) The server will receive the data and process the command (assume
server buffer size of 8K).  When completed, the server will place the
return data in its communication buffer and send it to the client.
For this example, we will assume the return data has a size of 7K
bytes.
(3) The first two bytes of the data will have a value of 7K
indicating the size of the data in the communication buffer.
(4) Because of its buffer size (4K bytes), the client will only
receive the first 4K bytes of data from the server; however, it will
attempt to copy 7K from it buffer as indicated by the 2-byte-length
field.

      The following is a description of the solution.
(1) When attempting to make a connection request, the client will
allocate its communication buffer (size equal to the RQIOBLKSZ
parameter) and send th...