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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.
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.
Identify a virtual partition
A virtual partition is identified by a calendar index or a time stamp.

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.
    - 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.
      - Define virtual partitions by assigning a calendar
        To virtually partition time series data, a time series calendar must be assigned to the time series virtual table in a data mart. Use the ifx_TSDW_setCalendar() routine to assign a calendar to a time series virtual table in a specific data mart.
      - Identify a virtual partition
        A virtual partition is identified by a calendar index or a time stamp.
      - Limit the size of data with time windows
        You can limit the amount of data in a data mart for time series data by using time windows.
      - Refresh time series virtual partition
        After you define virtual partitions and load the data mart, you can refresh the time series data for a single virtual partition by running the ifx_TSDW_updatePartition() routine.
      - Example: Accelerating time series data
        Use this step-by-step example as a guide to accelerate Informix® time series data by using Informix Warehouse Accelerator.
      - Example: Continuous refresh of accelerated time series data
        Use this step-by-step example as a guide to continuously refresh accelerated Informix® time series data by using Informix Warehouse Accelerator.
  - 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.

Identify a virtual partition

A virtual partition is identified by a calendar index or a time stamp.

The calendar index is a positive integer value, where 0 is the first virtual partition. For example, for the 2010monthly calendar used in the example, the calendar index 0 identifies the virtual partition for January 2010, and the calendar index 1 identifies February 2010.

When using a time stamp, the time stamp value is internally mapped into a calendar index. For the 2010monthly calendar used in the example, all time stamps between '2010-01-01 00:00:00.00000'::datetime year to fraction(5)', including this value, and '2010-02-01 00:00:00.00000'::datetime year to fraction(5)', excluding this value, identify the virtual partition for January 2010.

The time stamp is automatically extended to 'datetime year to fraction(5)'. For example, '2010-01'::datetime year to month' is equivalent to '2010-01-01 00:00:00.00000'::datetime year to fraction(5)'.