The information provided applies to the new Informix Server and IWA Version 12.10.FC1.
The latest Release of Informix Server and the Informix Warehouse Accelerator (IWA) a few days ago contains quite useful new features that will be described briefly in the list below.
( The new URL to the official Informix Warehouse Accelerator Version 12.10
- Two new methods to refresh data in an existing data mart without
having to fully reload the complete data set into the data mart. Both
methods have the advantages, that compared to a full reload, less data
is moved and the data mart remains available for query acceleration
during the refresh operation.
- Automatic Partition Refresh (aka RefreshMart) checks in the warehouse database for changed partitions. These are either whole unfragmented tables or fragments of a fragmented table. Only the data of partitions that have been changed will be loaded again into the data mart. In addition, fragments detached from tables in the warehouse database will have their corresponding partition dropped from the data mart. Likewise, fragments newly attached to tables in the warehouse database will have their corresponding partition loaded into the data mart. This method is most effective for warehouse databases containing fragmented tables, where data is removed by detaching older fragments and new data is added by attaching new fragments.
- Trickle Feed can be set up for a data mart to continuously feed the data that gets inserted into the fact tables in small portions (as a trickle) to the data mart. This is most useful for warehouse databases where accelerated queries should utilize the newest data, assuming that most of the data changes in the warehouse database are inserts to fact tables. Other data changes to the fact tables, i.e. updates and deletes, are not propagated by trickle feed to the data mart. Optionally, the trickle feed can be set up in a way to also perform partition refresh of dimension tables in defined time intervals.
- Integration of TimeSeries data with IWA
Informix TimeSeries data normally is stored in the database in a special format that maximizes space utilization and performance of TimeSeries specific queries using the TimeSeries Datablade© functions. To speed up general analytic queries that are not using the TimeSeries specific syntax, but still should use the TimeSeries data, IWA can now be utilized. The TimeSeries data can be loaded into a data mart via the Virtual Table Interface.
- Enhanced support for SQL Elements
- Multiple queries combined with UNION or UNION ALL into a single SELECT statement are now considered for acceleration. Qualifying queries will be accelerated and their results will be combined with results from the queries executed locally by the Informix Server.
- When using the ANSI SQL Standard OLAP window functions, now supported by the Informix Server, IWA can accelerate the underlying SELECT, JOIN and PROJECT operations of the query. Before handing their results to the user, Informix Server will perform the OLAP and ORDER BY portions of the query.
- The new keywords NULLS FIRST or NULLS LAST as options in the ORDER BY clause are now supported by IWA. Previously NULL was always considered the lowest value and appeared in the sorting order accordingly.
- Additional query syntax, that now can be accelerated by IWA:
- Aggregate functions inside a CASE construct
- Multiple DISTINCTs
- COUNT of DISTINCT with CASE construct
- Integration with the IBM OpenAdmin Tool (OAT)
IWA and its data marts can now be administered using OAT Version 3.11. Tasks supported by OAT include creating an accelerator, monitoring it, as well as creating, loading, monitoring and dropping data marts. You can get OAT Version 3.11 from http://www.openadmintool.org .
- New SQL routines for IWA and data mart administration
IWA includes new procedures and functions that can be called from any SQL client application. The names of these new routines start with the prefix "ifx_", e.g. "ifx_createMart()". Usage of these routines is simplified, as no handling of CLOB data is needed.
- Privilege control for data mart administration
From now on, users need to have required privileges to be able to perform IWA and data mart administrative tasks. By default user "informix" has these privileges. Other users need to have the DBA role or must be granted the WAREHOUSE privilege explicitly. The latter is done by running the "grant admin" command with the argument "WAREHOUSE" via the SQL administration API.
- New utility "ondwachk"
This new utility script is used to check, that the setup and configuration of the Informix Server instance is valid for accelerating queries using IWA. As such, the utility is part of the Informix Server installation, located in $INFORMIXDIR/bin , and run from within the Informix Server instance's environment. It will quickly check a list of prerequisites for successful connection to IWA, like the matching of IWA and Informix Server versions, existance and configuration of a SmartBLOB Space, an appropriate listener thread is running, a DWA VP is started or can be started automatically, etc.