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Data warehousing
In addition to designing and implementing Informix® dimensional databases, you can use tools to create data warehouse applications and optimize your data warehouse queries.
Informix® Warehouse Accelerator
The Informix® Warehouse Accelerator Administration Guide includes information about installing and configuring the accelerator server, creating data marts, accelerators, and accelerated query tables (AQTs).
Data marts and AQTs
For efficient query processing, the accelerator server must have its own copy of the data. The data is stored in logical collections of related data, or data marts. A data mart specifies the collection of tables that are loaded into an accelerator and the relationships, or references, between these tables.
Update a data mart
You can refresh the data in a data mart. You can update the data mart definition when you change the warehouse schema.
Reloading the data mart
You can reload all the data in the data mart. Query acceleration is temporarily suspended.

Data warehousing
In addition to designing and implementing Informix® dimensional databases, you can use tools to create data warehouse applications and optimize your data warehouse queries.
- Dimensional databases
  The Informix® Data Warehouse Guide provides information to help you design, implement, and manage dimensional databases, and describes the tools that you can use to create data warehouses and optimize your data warehouse queries.
- Informix® Warehouse Accelerator
  The Informix® Warehouse Accelerator Administration Guide includes information about installing and configuring the accelerator server, creating data marts, accelerators, and accelerated query tables (AQTs).
  - Overview of Informix® Warehouse Accelerator
    Informix® Warehouse Accelerator is a product that you use to improve the performance of your warehouse queries.
  - Installation
    You can install Informix® Warehouse Accelerator on the same computer as the Informix database server, on a separate computer, or on a cluster (including a high-availability cluster).
  - Configuration
    You must configure the accelerator server to work with the Informix® database server.
  - Create an accelerator
    You create an accelerator by connecting the Informix® database server to the accelerator server.
  - Data marts and AQTs
    For efficient query processing, the accelerator server must have its own copy of the data. The data is stored in logical collections of related data, or data marts. A data mart specifies the collection of tables that are loaded into an accelerator and the relationships, or references, between these tables.
    - Accelerated query tables
      Accelerated query tables, or AQTs, store information about data marts that the database server uses to determine which queries can be processed by Informix® Warehouse Accelerator.
    - Data marts
      Typically, data marts contain a subset of the tables in your database. The data marts can also contain a subset of the columns within a table. This configuration is advantageous when you are using the TCP/IP loopback optimization between Informix® and IWA, because it provides a seamless experience for the customer.
    - Create a data mart
      After you configure the accelerator server and set up the connection between an accelerator and the database server, you need to create the data marts.
    - Deploy and load the data mart
      To deploy a data mart, you specify the accelerator that will contain the data mart definition file. When you load a data mart, the related data is unloaded from the Informix® tables and transferred to the accelerator server.
    - Types of tables for acceleration
      You can load and accelerate data from tables, external tables, synonyms, views, and time series virtual tables.
    - Update a data mart
      You can refresh the data in a data mart. You can update the data mart definition when you change the warehouse schema.
      - Reloading the data mart
        You can reload all the data in the data mart. Query acceleration is temporarily suspended.
      - Re-creating a data mart
        You can re-create a data mart to update the data mart definition. You can add or remove dimension and fact tables to or from the data mart. You drop the data mart and re-create it with the new definition. Query acceleration is temporarily suspended.
      - Replacing a data mart
        You can replace a data mart to update the data mart definition. You create a new data mart with a new definition and drop the original data mart. Query acceleration continues uninterrupted.
    - Drop a data mart
      You can drop a data mart if you no longer need the data mart or if you need to update the data in a data mart.
    - Data marts for time series data
      You can create data marts that contain tables that represent time series data. Typically, such tables are fact tables in the data mart.
  - Turning on query acceleration
    Before queries can be routed to the accelerator server for processing, you must set the use_dwa session environment variable.
  - SQL administration routines
    You can use the Informix® Warehouse Accelerator functions and procedures from the command line or in an application to automate administration tasks.
  - Reversion requirements for Informix Warehouse Accelerator
  - Troubleshooting
  - Sample warehouse schema
    The Informix® Warehouse Accelerator examples use this sample warehouse schema.
  - Sysmaster interface (SMI) pseudo tables for query probing data
    The SMI tables provide a way to access probing data in a relational form, which is most convenient for further processing.

Reloading the data mart

You can reload all the data in the data mart. Query acceleration is temporarily suspended.

About this task

You do not need to stop query acceleration. Between the time when you set the data mart to disabled mode and load the data mart, query acceleration is suspended and all queries are run by the Informix® database server.

Procedure

To reload the data mart:

If trickle feed is enabled, disable it.
Put the data mart in Disabled state.
Query acceleration is suspended.
Load the data mart.
When the load completes, query acceleration resumes.
Optional: Enable trickle feed for the data mart.

Example

The following statements disable trickle feed for the data mart, put the data mart in Disabled state, load the data mart, and enable trickle feed for the data mart:

EXECUTE FUNCTION ifx_removeTrickleFeed('MyAccelerator', 'Datamart1');

EXECUTE FUNCTION ifx_setMart('MyAccelerator', 'Datamart1' 'OFF');

EXECUTE FUNCTION ifx_loadMart('MyAccelerator', 'Datamart1', 'MART');

EXECUTE FUNCTION ifx_setupTrickleFeed('MyAccelerator', 'Datamart1', 5);