The fetch buffer is a memory location in a client-server environment where cursor data received from the server and held before transmit to the application. Setting a bigger fetch buffer size can significantly improve query performance by reducing network traffic. It is the amount of data that client accepts from the server without waiting to send a "received" message which make the difference. Starting with Informix version 11.70.xC5, you can set the maximum size of the fetch buffer to 2 GB to increase query performance.
The FET_BUF_SIZE environment is used to set the size of the application fetch buffer. This environment variable can override the default setting for the size of the fetch buffer for all data types except BYTE and TEXT values. An ANSI database needs addition consideration; you must set transactions to READ ONLY mode for the FET_BUF_SIZE environment variable to improve performance, otherwise rows are returned one by one.
A valid FET_BUF_SIZE setting is in effect for the local database server and for any remote database server from which you retrieve rows through a distributed query in which the local server is the coordinator and the remote database is subordinate. The greater the size of the buffer, the more rows can be returned, and the less frequently the client application must wait while the database server returns rows. A large buffer can improve performance by reducing the overhead of filling the client-side buffer.
In case of an invalid FET_BUF_SIZE setting, Informix not generates any error. It uses the default fetch buffer size.
The combination of fetch buffer, communication buffer (the "b" option in the sqlhosts file), network driver size and application cursor can enhance the query performance farther.
Upgrading Informix Dynamic Server Version 10.00 to Versions 11.10 or 11.50:
When installing IDS 11.10 or 11.50, if you choose the option "Upgrade from the previous version", all the server binaries will be upgraded to the newer version(s) automatically.
Upgrading Informix Dynamic Server from Version 11.10 to 11.50:
When installing IDS 11.50 on Windows, direct upgrade from IDS 11.10 is not supported. If “Upgrade from the previous version” is selected the following message pops up. Installer stops beyond this point.
Since the support to install both 11.10 and 11.50 on the same machine exists, it is recommended to choose the option “Install into a default/different directory” (shown in the panel below) to install IDS 11.50. Note: This will not upgrade IDS 11.10 to IDS 11.50.
As part of providing a folder name to install the product, a completely new path must be supplied. If the folder selected already contains binaries from IDS 11.10, then the following message pops up.
User can respond to the question “Do you want to select another folder? “. Clicking “yes”, the installer returns to the destination panel where they can provide a different folder. Clicking No, the installer goes to finish panel
The recommended approach to upgrade to 11.50 is
Snigdha Sahu[Read More]
OAT 2.21 has incorporated IDS Enterprise Replication monitoring, a plugin manager to allow customization of OAT functionality and an automated installer on Mac OS X. OpenAdmin Tool for IDS (OAT) is a PHP-based Web browser administration tool for IDS 11 and IDS 11.5 that provides the ability to administer multiple database server instances from a single location. OAT makes administration easy by allowing you to drill down on resource usage and events, view query performance statistics, and much more. And since the tool is written in PHP and available as open source, you can customize it with your own business logic and installation requirements.
New feature highlights of OpenAdmin Tool for IDS version 2.21 include:
Download OAT version 2.21 now at https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?lang=en_US&source=swg-informixfpd .
Leo Chan[Read More]
CommonDevelopment ToolOne of the big ideas recently proposed by IBM, and further proof of our commitment to IDS, has been the idea of a common setof clients tools (like a Java Common Client (JCC), for example). If you aregoing to have a common set of clients, or programming interfaces, itmight not be a bad idea to have a common development tool that willallow you to use these common clients, for both DB2 and IDS. Well IBMhas released in beta an Eclipse based common tool that allows that. Forthose who want to jump right in here is the link:
IBMData Server Developer Workbench 9.5
As with many things IBM , since this is an open beta the actual name atthe time of release may change. I will be blogging on thisproduct over the next few weeks covering its capabilities from the IDSside of the tool. So far there will be 5 parts to this report, notcounting this introduction.
Part 1 - Installation for IDS
Part 2 - Setting up your workspace and connecting to IDS.
Part 3 - The Database Explorer window.
Part 4 - ER Diagramming
Part 5 - The SQL Builder and The SQL Editor Windows.
Part 6 - PureQuery and IDS