SQL Management for IT Users Intermediate Level

John Tappero, Software Engineer Andrew Glasfeld, Software Engineer

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• Overview of SQL Server 2005/2008. • SQL Server tools. • Common administrative tasks. • Tips and diagnostic advice for reliability and performance. • Scaling SQL Server.

Class objectives

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• It is a relational database management system (RDBMS). • Maintains valid relationships between data. • Ensures that data is stored correctly. • Can recover data when the system fails.

What is SQL Server?

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• It uses “client/server” architecture. • This separates the workload into tasks that run on server computers

and those that run on client computers. • The “client” is responsible for business logic and presenting data to

the user. • SQL Server (the “server”) manages the databases and allocates the

available server resources.

What is SQL Server? (cont’d)

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• Microsoft SQL Server uses Transact-SQL (T-SQL). • SQL is a set of commands to retrieve, modify or delete information.

The American National Standards Institute (ANSI) has defined the standards for SQL.

• T-SQL is Microsoft's version of SQL. • T-SQL supports the ANSI SQL specification, but more.

What is SQL Server? (cont’d)

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• What’s new in SQL Server 2005 • SQL Server Management Studio. • SQL Server 2005 SP1 added Database Mirroring.

• What’s new in SQL Server 2008

• Transparent data encryption. • Enhanced performance and data auditing. • Enhanced database mirroring. • Performance data collection. • Backup compression. • Resource governor.

What is SQL Server? (cont’d)

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• What is SSMS? • A utility to perform system management tasks on SQL Server and its

databases. • What can you do with SSMS?

• Set up SQL Server login accounts. • Back up your main SiriusSQL database. • Restore your main SiriusSQL database. • Detach your main SiriusSQL database. • Attach your main SiriusSQL database. • Export SQL Server logs. • Query Window: Run any valid T-SQL code (scripts).

SQL Server Management Studio (SSMS)

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• Backups are the second most important task. • Restoring a backup is the most important. • Note: The following are only suggestions.

Better backups – understanding the details

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• SQL Server Transaction Logs record all database activity as it comes through. Transaction Logs have an LDF extension.

• File Groups are a database that is broken up into multiple physical files. Each of these have an NDF extension.

• Siriusware broke up the MDF into three File Group files called SiriusSQL.MDF, SiriusSQL_Transact.NDF, SiriusSQL_Logs.NDF

• The transaction log is still SiriusSQL.LDF.

Transaction Logs and File Groups

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• Don't confuse SQL Server Transaction Logs with the files SiriusSQL_Transact.NDF and SiriusSQL_Logs.NDF.

• Don’t confuse SQL Server Transaction Logs with the tables in the SiriusSQL database called “transact”, “gst_log” and “acc_log”.

Transaction Logs and File Groups (cont’d)

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• The Recovery Model is set as a property of each database. • SQL Server 2000 defaulted to the "Simple" recovery model. • SQL Server 2005 and 2008 defaults to the "Full" recovery model. • What does Microsoft think is best for you today?

Types of Recovery Models

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• Transaction Log is automatically pruned (truncated) immediately after a transaction is committed (every basic INSERT, UPDATE and DELETE statement).

• This means that the LDF file never grows. • This is the default for your SiriusSQL database.

Simple Recovery Model

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• So why doesn't everyone use Simple? • Because you are more at risk in the event of failure. • Choose Simple to keep your life simple.

Simple Recovery Model (cont’d)

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• This is the same as Full recovery model except bulk operations are not logged.

• Code in Siriusware's software does not perform bulk operations, so Bulk Logged is essentially the same as Full Recovery.

Bulk Logged Recovery Model

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• This logs all database activity and KEEPS it in the log until a transaction log backup (or a transaction log truncate) takes place.

• Recover data right up to the moment of failure. • First restore your first full backup, and then restore each transaction log

backup.

Full Recovery Model

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• Requires periodic (i.e. nightly) full database backups AND • Requires frequent (i.e. hourly) transaction log backups. • Don’t use this model unless you have a full-time DBA on staff.

Full Recovery Model (cont’d)

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• Is a complete snapshot backup of the database. • They can take up as much space as the MDF and NDF files.

Full Database Backup

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• Backs up only what is different since the last Full Backup. • They grow larger throughout the day as more data changes. • After the next full backup, the backups begin to be small again. • They are small and happen quickly, so you can do them frequently. • Allows restoration much closer to the time of failure.

Differential Backup

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• Minimal fuss backup scheme for a small or medium sized venue: • Perform a Full backup every night. • Perform Differential backups every hour starting at 9:00am until an hour

after sales points are closed. • Interactive example

Backup suggestion

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• First restore your most recent Full backup • Then restore the latest Differential backup (if you performed any

Differential backups). • Two scenarios – one where the database name appears in the list of

databases, and one where the name doesn’t appear.

Restoring a backup

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• Simply right-click on the database name, tasks, Restore Database. • It will conveniently select the most recent Full backup as well as the most

recent Differential backup to restore.

Restoring when database name is available

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• Right-click on the word "databases" and choose "restore databases". • First, enter the new database name (i.e. SiriusSQL). • Choose "From Device" instead of the "Database“. • You must select a "device" to restore from. • Add the full backup file to the device list. • IMPORTANT: If you also have a Differential backups, select "Leave the

database non-operational" in the Options tab. • Also, you may change the path to where you are restoring, if the path has

changed. You must change the path for all four files in the backup set. • Click OK. Now restore the differential (if any). • Repeat the process, but this time for the differential. • Note, you may need to modify all of your workstation ODBC connections.

Restoring when the name is not available

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• You can set up backups in a maintenance plan as well. • Used to reorganize the indexes so performance is increased. • Also used to check the database integrity. • Use the Maintenance Plan Wizard to easily create maintenance plans. • Additionally, you can use the Maintenance plan designer in SQL Server

2005.

Maintenance Plans

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• Note: SQL Server 2005 requires you to have the SQL Server Integration Services (SSIS).

• In SQL Server 2005, select "New Maintenance Plan Wizard" in 2005, unless you are an experienced user.

• Interactive example

Maintenance Plans (cont’d)

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• Windows Authentication Mode or Mixed Mode. • Windows Authentication Mode -> only logins that use Windows security

credentials are supported. • Mixed Mode -> Windows Authentication mode PLUS its own set of SQL

Server login accounts. • Siriusware modules use Mixed Mode authentication. • Use Windows Authentication Mode for other user access.

Managing User Security

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• Uses “trusted connections” to SQL Server. • SQL Server will not recognize users or groups that you have deleted and

recreated in Windows. • Trusted domains also work with SQL Server. • First create the Windows groups and users. • Need Windows administrator rights. • Use SSMS to grant access.

Windows Authentication Mode

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• SQL Server manages it’s own user list. • No SQL Server login account = no access. • Use SSMS to create a new user under the Security / Logins folder.

SQL Server Mixed Mode

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• This is a special login account, with a password of “sirius”. • It has only “Public” permissions to the SiriusSQL database. • Nobody should ever use the “sirius” user account! • Don’t change access rights to the “sirius” login account! • Need access to the SiriusSQL database? Set up your own access.

The “sirius” login account

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• Commonly Used Problem Solving Tools • Profiler and the default trace • Notepad • Event Viewer

SQL Server Troubleshooting

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• Information Gathering Phase • Step 1: Gather the facts. • Step 2: Test in different environments. • Step 3: Review the SQL Server Error Log and Windows Event logs. • Step 4: Review the default trace. • Step 5: Review your own change log and Siriusware release notes.

• Analysis Phase

• Review all the data you collected.

SQL Server Troubleshooting

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• Why is my SQL Server running slow? • Your server or network is not properly scaled for your workload. • Backups or other maintenance operations occurring during business

times. • User queries from 3rd party products (i.e. Excel).

• Users may not be experienced using these tools.

• Can create locked rows, pages or tables.

• These tools are sometimes file-based or table-based.

SQL Server Performance

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• Screen savers. • Network issues. • Report Manager reports with broad criteria. • No Limits on Max4Sale items. • Circular referencing for modifiers on modifiers. • Terminal Services, or Citrix software.

Some reasons for server slowness (cont’d)

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• Given all this, how do you figure out what the problem is? • Observation and deduction. • Try to tie your symptoms to an event or pattern.

Why is my SQL Server running slow?

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• So, what if there is no discernable pattern? • You must then act while the problem is occurring. • Running a trace can help.

Why is my SQL Server running slow?

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• Task Manager • Processes tab: Sort by the CPU column descending. • Processes tab: Add a “CPU Time” column. • Performance tab: “Commit Charge total” versus “Physical Memory

total”. • Performance tab: “Available Physical Memory” < 4MB.

Useful methods for finding bottlenecks

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• Disk Reads vs. Disk Writes • Is your disk I/O mostly reads or mostly writes? • Knowing the ratio of reads to writes of your server can help. • Heavy on writes -> avoid RAID 5 and use RAID 10 instead. • Heavy on reads -> RAID 5 is good. • Processes tab: Add “I/O Read Bytes” and “I/O Write Bytes” columns. • Give it 2 to 4 days to log the reads and writes. • If reads are roughly double or more than the writes -> RAID 5. • If writes are double or more than the reads -> RAID 10.

Useful methods for finding bottlenecks

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• The Performance Monitor • Under Windows Administrative Tools, run the Performance Monitor.

Add and view the following counters: • SQLServer: Buffer Manager: Buffer cache hit ratio. Should be at or above 90.

• SQLServer: Buffer Manager: Free pages. Should not have a sustained value of 4 or less for more than 2 seconds.

• SQL Server: Buffer Manager: Page Life Expectancy. Should be above 350.

• Memory: Available Bytes. Should be 10MB or more.

• SQLServer: SQL Statistics: Batch Requests/Sec. Over 1000 batch requests per second indicates a very busy SQL Server, and could mean CPU bottlenecks. But this is a relative number, and the bigger your hardware, the more batch requests per second SQL Server can handle.

Useful methods for finding bottlenecks

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• Current SQL Server Activity • This shows you who is on your system and what is currently

happening within SQL Server. • sp_who2 and sp_lock3

• Determines who is on your system, what (if any) locks they have on your data and how much CPU time they used.

• Sp_who2 is built into SQL Server. • Sp_lock3 is a user created enhancement to Microsoft’s sp_lock2

stored procedure.

Useful methods for finding bottlenecks

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• Profiler • Profiler is a Graphical Interface to "SQL Trace". • Traces "record" SQL activity. • Leave it running to “catch” the culprit.

Useful methods for finding bottlenecks

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• Keep the database statistics up to date • SQL Server uses a cost-based optimizer. • Statistics are used to create an execution plan for a particular query. • Statistics are maintained on each table. • Use the UPDATE STATISTICS command or the sp_updatestats system

stored procedure.

Useful methods for finding bottlenecks

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• Be sure the “sirius” user account login has only “Public” permission to SiriusSQL and SiriusSQL_Training.

• Limit user access to the live data and don't make a “general” login. • If you have web applications that access the data, be sure to give them

their own login too for the same reason (don’t use the “sa” login).

Preventing issues with a little security

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• Before considering scaling SQL Server, first optimize your applications and queries.

• This part is already done for you. • If things are still slow, scaling your SQL Server may be your next option. • There are two ways to scale SQL Server. You can “scale up” or “scale out”.

Scaling your SQL Server

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• Invest in better/faster hardware. • Good approach if your bottlenecks are hardware related. • Memory bottlenecks may be resolved by adding additional memory or by

upgrading existing memory. • SQL Server 2005 -> remove the 2GB Virtual Address Space limit by using

the /3GB switch in the boot.ini file. • Consider faster storage subsystems, multiple disk controllers, or

implementing RAID.

Scaling Up

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• Multiple computers with data partitioned or replicated across them. • Requires much more planning than scaling up. • See http://blogs.msdn.com/sqlcat/archive/2008/06/12/sql-server-scale-

out.aspx for a list of good articles on scaling out.

Scaling Out

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1. Optimize the application before scaling 2. Address historical and reporting data 3. Scale up 4. Scale out when scaling up does not suffice

Should I scale up or scale out?

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• Microsoft SQL Server Books On-Line and Transact-SQL help files. • http://www.sql-server-performance.com • http://www.learnitfirst.com/Course/152/SQL-Server-2005-DBA.aspx • http://www.sqlservercentral.com • http://www.simple-talk.com/sql

• Thanks for attending!

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