Browse Prior Art Database

Sharing Conversations in a Distributed Data Environment

IP.com Disclosure Number: IPCOM000100295D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 1 page(s) / 50K

Publishing Venue

IBM

Related People

Crus, RA: AUTHOR [+5]

Abstract

In a distributed database environment supporting SQL statements, there are at least two database systems; the one at which the SQL statements are being presented and the one at which the data that is the object of the SQL statements resides. Communication between the database systems uses what are called conversations. A conversation is a communication path between two database systems. This invention describes how SQL statements may be allocated to conversations.

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Sharing Conversations in a Distributed Data Environment

       In a distributed database environment supporting SQL
statements, there are at least two database systems; the one at which
the SQL statements are being presented and the one at which the data
that is the object of the SQL statements resides.  Communication
between the database systems uses what are called conversations.  A
conversation is a communication path between two database systems.
This invention describes how SQL statements may be allocated to
conversations.

      According to this invention, a conversation is shared among
multiple SQL requests that refer to data at the same remote site.
Since conversations for cursors for which the answer set cannot be
blocked (i.e., cursors which must communicate synchronously) are
dormant between SQL statements that refer to that cursor, such
conversations are candidates for sharing.  Conversations can be
shared among both non- cursor related SQL statements and cursor
related statements for which the answer sets cannot be blocked, as
long as all such statements refer to data at the same remote site.
Conversations for cursors for which the answer set can be blocked
remain associated strictly with their respective cursors, and cannot
be shared.

      When it becomes necessary to allocate a conversation for a non-
cursor related SQL statement or for a cursor for which the answer set
cannot be blocked, a check is first be made for a "shareable"
conversat...