Datawarehousing Concepts and Tools

In Datastage, the degree of parallelism, resources being used, etc. are all determined during the run time based entirely on the configuration provided in the APT CONFIGURATION FILE. This is one of the biggest strengths of Datastage. For cases in which you have changed your processing configurations, or changed servers or platform, you will never have to worry about it affecting your jobs since  all the jobs depend on this configuration file for execution. Datastage jobs determine which node to run the process on, where to store the temporary data , where to store the dataset data, based on the entries provide in the configuration file. There is a default configuration file available whenever the server is installed.  You can typically find it under the <>\IBM\InformationServer\Server\Configurations  folder with the name default.apt. Bear in mind that you will have to optimise these configurations for your server based on your resources. Basically the configurati...

In parallel we have Dataset which acts as the intermediate data storage in the linked list, it is the best storage option it stores the data in datastage internal format. In parallel we can choose to display OSH , which gives information about the how job works. In Parallel Transformer there is no reference link possibility, in server stage reference could be given to transformer. Parallel stage can use both basic and parallel oriented functions. Datastage server executed by datastage server environment but parallel executed under control of datastage runtime environment Datastage compiled in to BASIC(interpreted pseudo code) and Parallel compiled to OSH(Orchestrate Scripting Language). Debugging and Testing Stages are available only in the Parallel Extender. More Processing stages are not included in Server example, Join, CDC, Lookup etc….. In File stages, Hash file available only in Server and Complex flat file , dataset , lookup file set avail in parallel only. Server Trans...

Server job stages do not have in built partitioning and parallelism mechanism for extracting and loading data between different stages. To enhance the speed and performance in server jobs is to     - Enable inter process row buffering through the administrator. This helps stages  to exchange data as soon as it is available in the link.     - Using IPC stage also helps one passive stage read data from another as soon as data is available. In other words, stages do not have to wait for the entire set of records to be read first and then transferred to the next stage.    - Link partitioner and link collector stages can be used to achieve a certain degree of partitioning paralellism. All of the above features which have to be explored in server jobs are built in datastage Parallel jobs . The Px engine runs on a multiprocessor sytem and takes full advantage of the processing nodes defined in the configuration file. Both SMP and MMP archi...

After upgrading Informatica PowerCenter, the INFA_HOME operating system environment variables must be set to a new PowerCenter installation path: For example, when upgrading from 9.0 to 9.0.1, the path: INFA_HOME=/opt/Informatica/9.0    is changed to path    INFA_HOME=/opt/Informatica/9.0.1 Other PowerCenter environment variables are relative to the INFA_HOME environment variable. Therefore, one need not apply any further changes, but it is worthwhile to check if the above statement is true. An example setting for other PowerCenter environment variables is presented below: INFA_HOME=/opt/Informatica/9.0.1 INFA_DOMAINS_FILE=$INFA_HOME/domains.infa PM_ROOT=$INFA_HOME/server/infa_shared PM_HOME=$PM_ROOT PATH=$PATH:$INFA_HOME/server/bin LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$INFA_HOME:$INFA_HOME/server/bin JRE_HOME=$INFA_HOME/Java For each Integration Service make sure that $PMRootDir variable is set properly. Is should be set to path: /server/infa_...

Introduction: Capturing and preserving the state of data across time is one of the core functions of a data warehouse, but CDC can be utilized in any database or data integration tool. There are many methodologies such as Timestamp, Versioning, Status indicators, Triggers and Transaction logs exists but MD5 function outlines on working with Checksum. Overview: MD5 stands for Message Digest 5 algorithm.It calculates the checksum of the input value using a cryptographic Message-Digest algorithm 5 and returns a128-bit 32 character string of hexadecimal digits (0 - F). Advantage of using MD5 function is that, it will reduce overall ETL run time and also reduces cache memory usage by caching only required fields which are utmost necessary. Implementation Steps : Identify the ports from the source which are subjected to change. Concatenate all the ports and pass them as parameter to MD5 function in   expression transformation Map the MD5 function output to a checksum outp...