Home > Articles > Data > SQL Server

Like this article? We recommend

Availability Features

With the introduction of the Internet to "web-enable" businesses, demand for service has increased exponentially. Customers expect to be able to browse and order products online at any time—when they're at home in the morning reading the newspaper, or even at 2 a.m. when they should be in bed asleep!

Whatever the individual circumstances of the customer, they all want reliable, efficient service at all hours. Recognizing these demands, Microsoft provides a number of key features in SQL Server 2000 to assist businesses in delivering highly available and fast applications.

NOTE

Some of the features discussed in this article are not available with all editions of SQL Server 2000 and Windows 2000. You may need to purchase Windows 2000 Advanced Server or Windows 2000 DataCenter in conjunction with SQL Server 2000 Enterprise Edition.

Clustering Support

Clustering is not a new concept in the RDBMS world; in fact, some of the first-ever clusters were developed by Digital Equipment Corporation (DEC), and Oracle Corporation utilized these clusters as early as 1987!

However, this is the first time that Microsoft has implemented clustering inside SQL Server as a feature that's easy to implement out of the box. SQL Server v7.0 supported clustering, although it definitely wasn't as easy to implement in that version as in SQL Server 2000.

There are two main types of clustering in SQL Server 2000:

  • Active/active clustering. In this type of clustering, an instance of SQL Server 2000 runs on each node (server) in the cluster, and actively serves requests. If a node fails, another node in the cluster takes over processing the failed node's work, as well as its own. As you can imagine, this has a performance impact on your servers and applications.

  • Active/passive clustering. Suppose you have a two-node cluster, with one of the nodes actively servicing requests while the other node sits idle. If the active node fails, the second node takes over the workload of the first node and continues processing while the first node is taken out of service and repaired. This avoids the performance impact of active/active clustering, but is more expensive because hardware sits idle.

Federated Database Servers

To improve the performance of large-scale enterprise applications, SQL Server 2000 incorporates distributed partitioned views (which are updatable), allowing your data to be horizontally partitioned over many different servers, sometimes known as groups or federations. For example, in a four-server federation, with a 10,000 row table you might have the following arrangement:

  • Server A contains records 1–2,500

  • Server B contains records 2,501–5,000

  • Server C contains records 5,001–7,500

  • Server D contains records 7,501–10,000

When a user submits a query to the distributed view, SQL Server queries the appropriate server for the requested data.

While this scheme isn't load balancing, it offers enterprises a simple and easy way to scale out their RDBMS solution. To provide more processing power, you can add another server and change the indexes to incorporate the new server.

NOTE

Each server in the federation is treated independently, and therefore can contain other data or databases without reliance or dependence on any other server within the federation.

Transaction Log Shipping

To further help provide reliable and highly available solutions, Microsoft has implemented transaction log shipping, which allows a company to keep a "warm" standby server on hand. As transactions are performed against the database, they're written to the log file (usually an .ldf extension). These transaction log files are "shipped" (sent) to a second instance/server of SQL Server 2000 at a time period specified by the database administrator. Suppose an update occurs to Table A on Server A. After a specified time has elapsed (such as 15 minutes), the same update to Table A occurs on Server B. In this example, if Server A fails, Server B can be rolled into production with only a 15-minute period of data latency.

Replication

Just as its predecessors did, SQL Server 2000 fully supports replication. Replication allows administrators to keep the data and database objects from multiple servers in sync, with a lower administrative overhead.

Replication may be configured for any of the following settings:

  • Snapshot. As the name suggests, this is a snapshot of the data at a specific point in time. The data for a subscriber to the replication publisher is refreshed in its entirety. The subscriber doesn't need to monitor data changes. This is generally used for a one-way replication scenario, and where read-only data is required by the subscriber.

  • Transactional. With transactional replication, the subscriber receives an initial snapshot of the data and objects, and then updates as the data changes. This requires the subscriber to be notified of changes, which then must be applied as required. This method is generally used in a one-way replication scenario.

  • Merge. Merge replication allows several instances of SQL Server to interact autonomously. When the data changes within one instance of SQL Server, the other instances are notified and accept the changes, and vice versa. All servers can collect data and act upon the changes independently. This type of replication requires more overhead to manage and can result in more data conflicts than other types of replication. This is generally used for a two-way replication scenario.

These prominent availability features of SQL Server 2000 allow many organizations to provide reliable and scalable solutions for their clients. Now let's take a look at SQL Server 2000 integration by examining the environmental features of the RDBMS.

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.

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