sql server

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VMware View 5 Implementation : Installing Microsoft SQL Server (part 2)

After the SQL instance is installed, it is important to ensure your SQL databases are backed up properly. Microsoft SQL 2008 makes this process easy to configure.

VMware View 5 Implementation : Installing Microsoft SQL Server (part 1)

It is quite common to run into a deployment in which the SQL Server instance is already up and running, but the management tool has not been installed. Because the 2008 Management Tools are no longer available as a separate download, it is possible to use SQL Express Management Studio 2005.

Microsoft SQL Server 2012 : Knowing Tempdb - Troubleshooting Common Issues (part 3) - Troubleshooting Space Issues

Troubleshooting SQL Server implies a reactive activity; an issue has occurred that now needs to be fixed. That may be true but one of the differences that separates an average SQL Server professional from a good one is knowing about a problem before it has an impact on a live system.

Microsoft SQL Server 2012 : Knowing Tempdb - Troubleshooting Common Issues (part 2) - Latch Contention - ikelihood of it happening. Multiple Tempdb Data Files

If you’re a DBA rather than a developer, you might be tempted to opt for this solution first. Recall that there is a set of allocation pages at the start of each data file, so if you have more than one file and can balance the load between them you’ll be less likely to get a hotspot on the allocation pages compared to a single file.

Microsoft SQL Server 2012 : Knowing Tempdb - Troubleshooting Common Issues (part 1) - Latch Contention - Allocation Page Contention

Imagine that you take an action within an application that needs to create a temporary table. To determine where in tempdb to create your table, SQL Server will read the SGAM page (2:1:3) to find a mixed extent with free space to allocate to the table.

Microsoft SQL Server 2012 : Knowing Tempdb - Overview and Usage (part 2) - The Version Store

Many features in SQL Server 2012 require multiple versions of rows to be maintained, and the version store is used to store these different versions of index and data rows.

Microsoft SQL Server 2012 : Knowing Tempdb - Overview and Usage (part 1) - User Temporary Objects

To store data temporarily you can use local temporary tables, global temporary tables, or table variables, all of which are stored in tempdb (you can’t change where they’re stored).

SQL Server 2012 : Transact-SQL - Functions, Triggers

A trigger is a special kind of stored procedure that is executed when a special event happens within SQL Server. An event could include the execution of a given DDL or DML statement or a login to SQL Server.

SQL Server 2012 : Transact-SQL - Stored Procedures

A stored procedure is a block of T-SQL or .NET code that is stored within a database. This code is similar to other procedures in other languages because it accepts parameters as inputs and can provide output to the calling application or user. Stored procedures make building database applications easy.

SQL Server 2012 : Transact-SQL - Transactions

Transactions enable users to create T-SQL batch statements that are either completely applied or do nothing to the existing data. When changes are applied, it is said that the transaction has committed.

SQL Server 2012 : Transact-SQL - Data Manipulation Language (part 2)

Alternatively, you could have omitted the specific columns you wanted to insert. If you do this, SQL Server will assume that the first value will be for the first column definition, the second value entered will be for the second columns definition, and so on.

SQL Server 2012 : Transact-SQL - Data Manipulation Language (part 1)

Most of what you’ll do with T-SQL centers around the Data Manipulation Language (DML). DML consists of the four statements SELECT, INSERT, UPDATE, and DELETE. These are the four statements that you use to get data into a database, update and delete that data, and get it back out again.

SQL Server 2012 : Transact-SQL - The VetClinic Sample Database Revisited, Data Types

Each data type has different characteristics, including how much space on disk each value takes up. A VARCHAR data type can be defined for 20 characters but takes up only a few bytes on disk.

SQL Server 2012 : Latch Contention Examples - UP Latches in tempdb, Spinlock Contention in Name Resolution

It is possible that the resource your request is waiting on might be in tempdb, rather than the database you have designed. You can see this by looking at the wait_resource field in sys.dm_exec_requests and, in particular, the first number, which indicates the database.

SQL Server 2012 : Latch Contention Examples - Queuing

Another typical scenario that can exhibit large amounts of latch contention is a system designed to allow queuing, for similar reasons to the last example, although exhibited in a slightly different way, and certainly resolved with a different method.

SQL Server 2012 : Latch Contention Examples - Inserts When the Clustered Index Key Is an Identity Field

A lot of advice suggests using an identity field for the clustered index on a table. Certainly there are benefits to doing this.

SQL Server 2012 : Latches and Spinlocks - Monitoring Latches and Spinlocks

In terms of monitoring latches, you’ve already been introduced to some of the DMVs. There’s more to monitoring latches than just DMVs, though. Performance Monitor also offers useful information about latches, as do extended events, which also provide information about spinlocks.

SQL Server 2012 : Latches and Spinlocks - SuperLatches/Sublatches

The queuing method of accepting all compatible latches each time the latching check is done only helps so far. It’s still a lot of work to manage all this. Enter the SuperLatch (or sublatch).

SQL Server 2012 : Latches and Spinlocks - Latch Types, Latch Modes

There are hundreds of different types of latch, most of which you are unlikely to encounter in any meaningful way when you are working with SQL Server. While latch waits will occasionally show up in sys.dm_os_wait_stats, you normally have to actively search for them. As a rule, they don’t come to you.

SQL Server 2012 : Understanding Latches and Spinlocks (part 3) - Latching Example - With Latching

With latches, Transaction 1 holds the EX latch for as long as it is needed to both write the row and update the page header and offset. Only then does it release the latch and allow another transaction in.

SQL Server 2012 : Understanding Latches and Spinlocks (part 2) - Latching Example - Without Latching

This part of the example represents a world without latches. Assume that the row containing the values (2,200) in Transaction 1 arrived at the page a fraction of a second before Transaction 2, when the values (3,300) are written. Transaction 1 writes to Slot 1

SQL Server 2012 : Understanding Latches and Spinlocks (part 1) - Latching Example

Running DBCC IND will provide information about the pages that are used in the table. You will use the PagePID value of the row which has a PageType value of 1.

SQL Server 2012 : Latches and Spinlocks - Symptoms (part 2) - Measuring Latch Contention, Measuring Spinlock Contention , Contention Indicators

A latch is like a lock on a piece of memory. As more threads get involved, they will start to compete to access the same pieces of memory, causing blocking. Blocking due to latch contention is exhibited in waits; but unlike a lock, a latch can be released as soon as the physical operation is completed.

SQL Server 2012 : Latches and Spinlocks - Symptoms (part 1) - Recognizing Symptoms

If your transactions per second figure is dropping as you enable extra processor threads, and your average latch waits are increasing at a rate greater than the throughput, then you quite possibly have a problem with latch contention.

SQL Server 2012 : XML and the Relational Database - Querying XML Data Using XQuery (part 2) - SQL Server XQuery in Action, XML DML

The W3C XQuery specification does not provide a way for you to modify XML data as you can modify relational table data using the INSERT, UPDATE, and DELETE keywords in T-SQL. So Microsoft has created its own XML data manipulation language, XML DML, which is included in its own XQuery implementation.

SQL Server 2012 : XML and the Relational Database - Querying XML Data Using XQuery (part 1) - Understanding XQuery Expressions and XPath

The XQuery specification contains several descriptions of requirements, use cases, and data models. We encourage you to review the specification to get a full understanding of what XQuery is all about.

SQL Server 2012 : XML and the Relational Database - Shredding XML Using OPENXML

Up to this point, you have been using FOR XML to compose XML from rows of data, but what if you already have XML data and want to shred it back into relational data? SQL Server 2000 introduced a feature called OPENXML for this purpose.

SQL Server 2012 : Running SQL Server in A Virtual Environment - MONITORING VIRTUALIZED DATABASE SERVERS

This section focuses on real-world monitoring of your virtualized database servers, identifying specific changes you may need to make to your monitoring processes and confirming which aspects of your current monitoring can remain unchanged.

SQL Server 2012 : Running SQL Server in A Virtual Environment - ARCHITECTING SUCCESSFUL VIRTUAL DATABASE SERVERS

To ensure SQL Server works at least as well as you expect, if not better, when you deploy it on a virtual server, design considerations must be made, which often involve settings and decisions that you wouldn’t have to make with a physical server deployment.

SQL Server 2012 : Running SQL Server in A Virtual Environment - IDENTIFYING CANDIDATES FOR VIRTUALIZATION

As virtualization’s popularity has grown, so has the debate about which server roles can be virtualized. Some of the very broad generalizations have contained a grain of truth. Certainly for a long time there was the view that production database servers could never be virtualized but virtualization technology has developed significantly to not normally make that a problem.

SQL Server 2012 : Running SQL Server in A Virtual Environment - MANAGING CONTENTION

In looking at some of reasons for virtualization’s popularity, the preceding sections identified the concept of contention, the capability to better use previously underutilized physical resources in a server in order to reduce the total number of physical servers deployed.

SQL server 2008 R2 : Reverting to a Database Snapshot for Recovery

If you have a database snapshot defined for a source database, you can use that snapshot to revert the source database to that snapshot’s point-in-time milestone. In other words, you consciously overlay a source database with the point-in-time representation of that database (which you got when you created a snapshot).

SQL server 2008 R2 : Setup and Breakdown of a Database Snapshot

You might actually be surprised to find out how easily you can set up a database snapshot. This simplicity is partly due to the level at which database snapshots are created: at the database level and not at the table level. Setting up a database snapshot only entails running a CREATE DATABASE with the AS SNAPSHOT OF statement.

SQL Server 2008 R2 : A Performance Monitoring Approach (part 3) - Monitoring Memory, Monitoring the Disk System

Memory, like a processor, is divided into segments for each process running on the server. If there is a demand for more memory than is available, the operating system has to use virtual memory to supplement the physical memory.

SQL Server 2008 R2 : A Performance Monitoring Approach (part 2) - Monitoring the Processors

The main processors of a server do the majority of the hard work, executing the operating system code and all applications. This is the next logical place to start looking at the performance of a system. With SQL Server 2008, you can identify the number of CPUs you want to utilize on your physical machine.

SQL Server 2008 R2 : A Performance Monitoring Approach (part 1)

One area of possible congestion is the network card or network interface; it does not matter how fast the server’s work is if it has to queue up to go out through a small pipe.

SQL Server 2012 : Running SQL Server in A Virtual Environment - EXTENDED FEATURES OF VIRTUALIZATION

Snapshotting a virtual server is very similar to how SQL Server’s own snapshot function works. In principle, the hypervisor suspends the virtual machine, or perhaps requires it to be shut down, and places a point-in-time marker within the virtual machine’s data files.

SQL Server 2012 : Running SQL Server in A Virtual Environment - VIRTUALIZATION CONCEPTS

Like any technology, virtualization covers a minefield of new terminology, features, and capabilities. To make things even more complicated, different vendors often use different terms for the same item. To help remove that ambiguity, this section covers the main terms and features commonly used by virtualization software currently being deployed.

SQL Server 2012 : Running SQL Server in A Virtual Environment - COMMON VIRTUALIZATION PRODUCTS

If you search for virtualization products using your favorite search engine, you’ll get dozens of results for different products, and many opinions about which is best. While it’s true that the virtualization marketplace is crowded, there are still only a handful of vendors that offer production-ready server virtualization products.

SQL Server 2012 : Running SQL Server in A Virtual Environment - WHY VIRTUALIZE A SERVER?

Additionally, virtual servers running SQL Server can benefit from some of the features that encapsulation brings, which we’ve just discussed; however, it’s at this point that some virtualization features, such as snapshotting a virtual server, Microsoft does not support using with SQL Server.

SQL Server 2012 : Running SQL Server in A Virtual Environment - AN OVERVIEW OF VIRTUALIZATION

A typical textbook definition of virtualization defines the concept of sharing a single physical resource between multiple isolated processes, by presenting each with their own virtual version of the physical resource.

SQL Server 2012 : Data Architecture (part 2) - Smart Database Design

More than a few databases do not adhere to the principles of information architecture, and as a result, fail to meet organization's needs. In nearly every case, the root cause of the failure was the database design. It was too complex, too clumsy, or just plain inadequate.

SQL Server 2012 : Data Architecture (part 1) - Information Architecture Principle, Database Objectives

Based on the Information Architecture Principle, every database can be architected or evaluated by six interdependent database objectives. Four of these objectives are primarily a function of design, development, and implementation: usability, extensibility, data integrity, and performance

SQL Server 2008 R2 : Performance Monitoring Tools (part 12) - Viewing Data Collector Set Results in Performance Monitor

To view a Data Collector Set report in Windows Performance Monitor, expand Reports and click User Defined or System. Then expand the Data Collector Set that you want to view as a report. Simply click the report that you want to view from the list of available reports. The report opens in the console pane.

SQL Server 2008 R2 : Performance Monitoring Tools (part 11) - Creating Data Collector Sets in Performance Monitor

A Data Collector Set is the building block of performance monitoring and reporting in Windows Performance Monitor. It organizes multiple data collection points into a single component that can be used for review or to log performance counters.

SQL Server 2008 R2 : Performance Monitoring Tools (part 10) - Creating an Extended Events Session

Windows Performance Monitor is a graphical tool that provides a visual display of built-in Windows performance counters, either in real-time or as a way to review historical data. It is supplied as part of the installation of any Windows server or workstation.

SQL Server 2008 R2 : Performance Monitoring Tools (part 9) - Creating an Extended Events Session

As you examine the CREATE EVENT SESSION T-SQL code, notice that two events are being created with the ADD EVENT statements. One will gather async IO requests, and the other will retrieve SQL Server–acquired locks on an object’s information.

SQL Server 2008 R2 : Performance Monitoring Tools (part 8) - Extended Events Catalog Views and DMVs

To get metadata information about what events, actions, fields, and targets have been defined, you can use the catalog views supplied with SQL Server.

SQL Server 2008 R2 : Performance Monitoring Tools (part 7) - SQL Server Extended Events

SQL Server Extended Events (SSEE) are truly the future event-oriented framework that all SQL Server–based systems and applications will be using going forward. Extended Events are highly flexible to define, are able to capture almost any action or event within your reach, are lightweight in their implementation, and are flexible enough to create simple or complex monitoring across multiple systems and environments.

SQL Server 2008 R2 : Performance Monitoring Tools (part 6) - SQL Server Utility

SQL Server 2008 R2 introduces a new multiserver management tool named the SQL Server Utility. This new tool takes performance monitoring in SQL Server to the next level by providing the capability to monitor specific performance metrics for one or more SQL Server instances in a single view from a single SQL Server instance.