When you use the Statement.setCursorName( ) method or the setFetchSize( ) method in the SybCursorResultSet class, jConnect creates a cursor in the database. Other methods cause jConnect to open, fetch, and update a cursor.
Versions of jConnect earlier than 4.0 can create and manipulate cursors only by sending SQL statements with explicit cursor commands to the database for parsing and compilation.
jConnect version 4.0 and later create and manipulate cursors either by sending SQL statements to the database or by encoding cursor commands as tokens within the Tabular Data Stream (TDS) communication protocol. Cursors of the first type are “language cursors;” cursors of the second type are “protocol cursors.”
Protocol cursors provide better performance than language cursors. In addition, not all databases support language cursors. For example, Adaptive Server Anywhere databases do not support language cursors.
In jConnect, the default condition is for all cursors to be protocol cursors. However, the LANGUAGE_CURSOR connection property gives you the option of having cursors created and manipulated through language commands in the database.
| Copyright © 2003. Sybase Inc. All rights reserved. |
|
|
