Hybrid Option and Data Extraction

Hybrid Option - After examining the legacy systems and the more modern applications in your corporation, it is most likely that you will decide that a single-plat form approach is not workable for your data warehouse. This is the conclusion most companies come to. On the other hand, if your company falls in the category where the legacy platform will accommodate your data warehouse, then, by all means, take the approach oho single-platform solution. Again, the single-platform solution, if feasible, is an easier solution.

For the rest of us who are not that fortunate, we have to consider other options. Let us begin with data extraction, the first major operation, and follow the flow of data unit it is consolidated into the load images and waiting in the staging area. We will now step through the data now and examine the platform options,

Data Extraction - In any-data warehouse it is best to perform the data extraction function from each source system on its own computing platform. If your telephone sales data resides in a minicomputer environment, create extract files tm the mini-computer itself for telephone sales. If your mail order application executes on the mainframe using an IMS database, then create the extract Ides for mail orders on the mainframe platform. It is rarely prudent to copy all the mail order database riles to another plat (Orin and then do the data extraction.

Initial Reformatting and Merging - After creating the raw data extracts from the various sources, the extracted files from each source ate reformatted and merged into a smaller number of extract files. Verification of the extracted data against source system repot and reconciliation of input and output record counts take place in this step. Just like the extraction step. It is best to do this step of initial merging in each set of source extracts on the source platform itself.

Preliminary Data Cleansing - In this step, you verify the extracted data from each data source for any missing values in individual fields, Supply default values, and perform basic edits. This is another step for the computing platform of the source system itself. However in some data warehouses, this type of data cleansing happens after the data from all sources are reconciled and consolidated. In either case the teat tires and conditions of data .from your source systems dictate when and where -this step must be performed for your data warehouse.

Transformation and Consolidation - This step comprises all the major data transformation and integration functions. Usually, you will use transformation software tools for this purpose. Where is the best place to perform this step? Obviously not in any individual legacy platform. You perform this step on the platform where your staging area resides.

Legacy Platform Stretched to Capacity

Legacy Platform Stretched to Capacity
In many companies, the existing legacy computing environment may have been around for a couple of decades and already fully stretched to capacity. The environment may be at a point where it can no longer be up-graded further to accommodate your data warehouse.

Non-availability of Tools. Software tools form a large part of the data warehouse infrastructure. You will clearly grasp this fact from the last few subsections of this chapter. Most of the tools provided by the numerous data warehouse vendors do not support the mainframe is minicomputer environment. Without the appropriate tools in the infrastructure, your data warehouse will fall apart.

Multiple Legacy Platforms. Although we have surmised that the legacy mainframe or minicomputer environment may be extended to include data warehousing, the practical fact points to a different situation. In most corporations, a combination of a few main-frame systems, an assortment of minicomputer applications, and a smattering of the newer PC-based systems exist side by side. The path roost companies have taken is from mainframes to minis and then to PCs. Figure 8-3 highlights the typical configuration. If your corporation is one of the typical enterprises, what can you do about a single-platform solution? Not much. With such a conglomeration of disparate platforms a single-platform option having your data warehouse alongside III the other applications is just not tenable.

Company's Migration Policy. This is another important consideration. You very well know the varied benefits of the client/server architecture for computing. 

Figure 8-3 Multiple platform in a typical corporation

You are also aware of the fact that every company is changing to embrace this new computing para-desgin by moving the applications from the mainframe and minicomputer platforms. In most companies the policy on the usage of information technology does not permit the platform perpetuation of the old platforms. II your company has a similar policy, then you will run be permitted to add another significant system such as your data warehouse on the old platforms.

Platform Options and Data Acquisition

Platform Options
Let us now turn our attention to the computing, platforms that are needed to perform the several functions of the various components of the data warehouse architecture. A computing platform is the set of hardware components, the operating system, the network, and the net-work software. Whether it is a function of an OLTP system or a decision support system like the data warehouse, the function has to be performed on a computing platform.

Before we get into a deeper discussion of platform options, let us get back to the functions and services of the architectural components in the three major areas. Here is a quick summary recap:

Data Acquisition - data extraction, data transformation, data cleansing, data integration, and data staging.
Data Storage: data loading, archiving, and data management.
Information Delivery: report generation, query processing, and complex analysis.

We will now discuss platform options in terms of the functions in these three areas. Where should each function be performed'? On which platforms? How could you optimize the functions?

Single Platform Option - This is the Iwo straightforward and simplest option for in implementing the data warehouse architecture. In this option, all functions from the end data extraction to the front-end query processing are performed on a single computing platform. This was perhaps the earliest approach, when developers were implementing data warehouses on existing mainframe, minicomputers, or a single UNIX -based saver.

Because all operations ill the data acquisition, data storage, and information deliver areas take place on the same platform, this option hardly ever encounters any compatibility or interface problems. The data flows smoothly from be to end without any platform-to-platform conversions. No middleware is needed. All tools work in a single com-putting environment.

In many companies, legacy systems are still running on mainframes or minis. Some of these companies have migrated to UNIX-based services and others have moved overt l systems in client/server environments as part of the transition to address the Y2K challenge. In any case, most legacy systems still reside on mainframes, minis or UNIX based servers. What is the relationship of the legacy systems to the data warehouse'? Remember, the legacy systems contribute the major part of the data warehouse data. If there companies wish to adopt a single-platform solution, that platform of choice has to I mainframe, mini, or a UNIX-based server.

If the situation in your company warrants serious consideration of the single-platform option, then analyze the implications before making a decision. The single-platform solution appears to be an ideal option. If so, why are not many companies adopting this option now? Let us examine the reasons.

350-001 Question 6

350-001 Question 6

While setting up remote access for your network, you type in the "aaa new-model" configuration line in your Cisco router. Which authentication methods have you disabled as aresultof this change? (Chooseallthat apply.)

350-001
 
A. RADIUS
B. RADIUS+
C. Extended TACACS (XTACACS)
D. TACACS
E. TACACS+
F. Kerberos

Answer: C, D

Explanation:
When you enable AAA, you can no longer access the commands to configure the older deprecated protocols, TACACS or Extended TACACS. If you decided to use TACACS or Extended TACACS in your security solution, do not enable AAA.

350-001 Question 5

350-001 Question 5   

You have forgotten the password to your Catalyst 5000 switch. Immediately after power cycling the switch, you are faced with the password prompt. What default password should yout ype i n?

A. cisco
B. abc123
C. sanfran
D. CTRL+ESC
E. No password, just hit the Enter key

Answer: E

Explanation:Password recovery in Cat 5000 switch is performed in the following way. Power cycle the switch. Hit the Enter key during the first 30 sec. The switch will allow you to get into the enable mode.You will have 60 seconds to change the password and save the configuration change made during this period.