informatica faq part4

Q: Can individual objects within a repository be restored from the back-up or from a prior version?
At the present time, individual objects cannot be restored from a back-up using the PowerCenter Repository Manager (i.e., you can only restore the entire repository). But, it is possible to restore the back up repository into a different database and then manually copy the individual objects back into the main repository.
Another option is to export individual objects to XML files. This allows for the granular re-importation of individual objects, mappings, tasks, workflows, etc.
Server Administration
Q: What built-in functions, does PowerCenter provide to notify someone in the event that the server goes down, or some other significant event occurs?
The Repository Server can be used to send messages notifying users that the server will be shut down. Additionally, the Repository Server can be used to send notification messages about repository objects that are created, modified or deleted by another user. Notification messages are received through the Informatica Client tools.
Q: What system resources should be monitored? What should be considered normal or acceptable server performance levels?
The pmprocs utility, which is available for UNIX systems only, shows the currently executing PowerCenter processes.
Pmprocs is a script that combines the ps and ipcs commands. It is available through Informatica Technical Support. The utility provides the following information:
- CPID - Creator PID (process ID)
- LPID - Last PID that accessed the resource
- Semaphores - used to sync the reader and writer
- 0 or 1 - shows slot in LM shared memory
(See Chapter 16 in the PowerCenter Repository Guide for additional details.)
A variety of UNIX and Windows NT commands and utilities are also available. Consult your UNIX and/or Windows NT documentation.
Q: What cleanup (if any) should be performed after a UNIX server crash? Or after an Oracle instance crash?
If the UNIX server crashes, you should first check to see if the repository database is able to come back up successfully. If this is the case, then you should try to start the PowerCenter server. Use the pmserver.err log to check if the server has started correctly. You can also use ps -ef | grep pmserver to see if the server process (the Load Manager) is running.
Metadata
Q: What recommendations or considerations exist as to naming standards or repository administration for metadata that might be extracted from the PowerCenter repository and used in others?
With PowerCenter, you can enter description information for all repository objects, sources, targets, transformations, etc, but the amount of metadata that you enter should be determined by the business requirements. You can also drill down to the column level and give descriptions of the columns in a table if necessary. All information about column size and scale, datatypes, and primary keys are stored in the repository.
The decision on how much metadata to create is often driven by project timelines. While it may be beneficial for a developer to enter detailed descriptions of each column, expression, variable, etc, it is also very time consuming to do so. Therefore, this decision should be made on the basis of how much metadata will be required by the systems that use the metadata.
There are some time saving tools that are available to better manage a metadata strategy and content, such as third party metadata software and, for sources and targets, data modeling tools.
Q: What procedures exist for extracting metadata from the repository?
Informatica offers an extremely rich suite of metadata-driven tools for data warehousing applications. All of these tools store, retrieve, and manage their metadata in Informatica's central repository. The motivation behind the original Metadata Exchange (MX) architecture was to provide an effective and easy-to-use interface to the repository.
Today, Informatica and several key Business Intelligence (BI) vendors, including Brio, Business Objects, Cognos, and MicroStrategy, are effectively using the MX views to report and query the Informatica metadata.
Informatica strongly discourages accessing the repository directly, even for SELECT access because some releases of PowerCenter change the look and feel of the repository tables, resulting in a maintenance task for you. Rather, views have been created to provide access to the metadata stored in the repository.
Additional products, such as Informaticas Metadata Reporter and PowerAnalyzer, allow for more robust reporting against the repository database and are able to present reports to the end-user and/or management.