SQL Server Reference Guide

Mar 28, 2003

␡

⎙ Print

< Back Page 340 of 365 Next >

In a previous tutorial, I explained the general process I follow to implement a Business Intelligence project. Starting in this series of tutorials, I’ll implement that process using a need I now have for some intelligence data. If you’re just joining me now, start out with this article first, since you’ll need that background for this tutorial. You’ve got a front-seat to my experiment as I work through it.

SQL Server 2008 introduces a new feature called the Management Data Warehouse. This feature uses yet another new feature, called the Data Collector, to store performance data from various systems in a single location. Together with a new set of reports, these features combine to show you how your systems are performing, and how you can correct many of them. I’m using the data store for that feature for my “source”.

As I mentioned in the last article, I’m in a bit of a circular pattern here. The first thing you normally want to do when you create a BI solution is to define the type of answers you want to be able to find. To do that in this situation, I need to know what kind of data I can use to find those answers. After all, I can’t report using data I don’t have. so in this case I actually need to evaluate the source data before I state what I want to learn from it. I’m using the standard Data Collectors in the Management Data Warehouse feature, and as I explained in the last tutorial I do know the data structures.

Since the Management Data Warehouse (MDW) comes with reports over the data I’ve collected, I have a leg up already on what kind of information I can see, and even a pretty good idea of how to see it. So that’s where I’ll start — I’ll dig in to the reports I already have, and then work backwards from that to find out the data they use. From there, I’ll know what level of detail I have and I can extrapolate from that the kind of rollups to do.

This process is one of the methods you can use to flesh out your own BI implementation. This is a “bottoms up” approach, since I have a set of pre-defined data that I understand well. In other cases, you might already know the questions the business wants to ask, and you’ll have to find or start collecting that data.

So step one is to evaluate the reports I have in the MDW (see the article referenced in the Note above for a quick description of those reports). The first MDW report I open is called “Server Activity”:

Figure 1

This looks promising. I can see CPU, Memory, I/O and Network data, along with the data that shows the waits the users are experiencing. It also has data that shows user activity. All that information is interesting, but not necessarily in a BI sense. For instance, is it important to know a particular wait occurred a year and a half ago? Probably not. Is it important to know about the network usage? Possibly. But what strikes me as very interesting is the part about the Disk I/O — if I could find out more about my drive subsystem, I can track growth, trend usage, and incorporate the data into my decision making about SAN purchases and more. I think I’ve hit on something I want to investigate further.

I click on the Disk I/O graph and get the following information:

Figure 2

Perfect — this is just the kind of thing I want. I’ll scroll down a little to see what the bottom part of the report shows:

Figure 3

Hmm. This is interesting as well, but since it shows pretty detailed information on the specific applications that are generating reads and writes, that isn’t as useful to me in the long run. That’s more of a short-term thing, at least in my case.

Now I’ll return to the main report overview for the MDW system, and select the “Disk Usage” report:

Figure 4

This report is exactly what I’m looking for. It shows not only the size of the database files, but the earlier sizes and even an average growth number. In fact, if I just kept this data, this would be one of the reports I would use. As it is, this data will “roll forward” every two weeks (that’s the retention period I have set) so I’ll use this report for a model of what I want.

Now on to the data that this report is using. You’ll have the same process to follow on your own systems — you can locate the reports or even application screens that show the data you want, and then find out what those screens and reports are using. There are a lot of ways to do that, but in this case it’s very simple.

Recall from the last tutorial in this series that I already have a full outline of the schema and what each table in the database does. That’s a rare privilege, so I’ll take full advantage of it and start with another tool I use quite often — the Database Diagrams in SQL Server Management Studio. I add four tables to the tool, and it automatically draws the relationships between them:

Figure 5

The reason this tool is so useful to me is that it shows the tables, their joins, and all of the columns I need.

Based on this diagram, I begin to work with the data in the MDW with two sets of queries that will show me the database read and write patterns, and the size of the data. The first query uses three tables that show me the read and write patterns, along with the “stall” information, which is the time that users spend waiting on the disk subsystem:

USE MDW;
GO

SELECT c.instance_name
, a.database_name
, a.logical_disk
, a.logical_file_name
, a.type_desc
, a.num_of_reads
, a.num_of_writes
, a.num_of_bytes_read
, a.num_of_bytes_written
, a.io_stall_read_ms
, a.io_stall_write_ms
, a.collection_time 
FROM
snapshots.io_virtual_file_stats a
	INNER JOIN core.snapshots_internal b
	ON a.snapshot_id = b.snapshot_id
		INNER JOIN core.source_info_internal c
		ON b.source_id = c.source_id
ORDER BY c.instance_name, a.database_name, a.type_desc;
GO

This information is very useful over the long term, since I can use it to show which databases are more read-oriented and which are more write-intensive. Why is that useful? Well, it allows me to pick the drive types I can use for a particular application — certain RAID levels do better on reads, others on writes. Since there is a cost associated with that, I want to put the right data in the right place. That also saves time, and power. Hey — green computing with a little BI!

The next query shows the file sizes and growth. I had to investigate the source of this data a little further, since I wasn’t sure of the size numbers the table was using. With a little experimentation, I found that the number was in pages, which in SQL Server is 8K. Then to get the size in megabytes, I divided that by 1024:

SELECT f.instance_name
, d.database_name
, (d.dbsize*8)/1024
, (d.logsize*8)/1024
, d.ftsize
, d.pages
, d.reservedpages
, d.collection_time
FROM snapshots.disk_usage d
	INNER JOIN core.snapshots_internal e
	ON d.snapshot_id = e.snapshot_id
		INNER JOIN core.source_info_internal f
		ON f.source_id = e.source_id	
ORDER BY d.collection_time;
GO

To find all that out, I just navigated down to the Management node of the server that is being monitored and double-clicked the Data Collectors that are feeding the Server Activity and Disk Usage reports. There in the details pane I saw the SELECT statements that are used for the reports. I’m not interested in the specific statements that collect the data, just how it is creating that data. That’s how I found out where they got the data from, and then I could do the number translations.

With all this information, I’m ready for the next step: creating my tables that will hold all this data for the analysis. I’ll cover that process next week.

InformIT Articles and Sample Chapters

There’s a lot more on the MDW feature in The SQL Server 2008 Management Data Warehouse and Data Collector elsewhere in this Reference Guide.

Books and eBooks

Before we get through with this project, you’ll need a good background on SQL Server Integration Services. I’ve got the reference for that right here: Microsoft SQL Server 2008 Integration Services Unleashed. (Also available as a downloadable eBook and in Safari Books Online)

Online Resources

To make sure I give credit where it is due, here is the reference from Books Online that I used in this tutorial.

< Back Page 340 of 365 Next >

🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Privacy Notice

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
Such marketing is consistent with applicable law and Pearson's legal obligations.
Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

As required by law.
With the consent of the individual (or their parent, if the individual is a minor)
In response to a subpoena, court order or legal process, to the extent permitted or required by law
To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
To investigate or address actual or suspected fraud or other illegal activities
To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020

Email Address