sql server 2005 資料庫管理達人一日體驗營

SQL Server 2005 資料庫管理達人一日體驗營

錢曉明資策會資深講師

議程• SQL Server 2005 新功能槪述• 檢視資料庫 Metadata• 災難復原

Piecemeal RestoreRestore a damaged page online如何利用資料庫快照還原被刪除的資料表 ?

• 資料庫監控與效能調教效能最佳化模型Default Trace透過 DMV 及 DMF 檢視效能瓶頸

• 異地備援Peer-to-Peer Replication

• 交易鎖定Snapshot Isolation Level

• 高可用度Database Mirroring Configurations

SQL Server 2005

What Is SQL Server 2005?

Relational Database Engine

.NET CLR

Analysis Services

Native HTTP Support

Service BrokerReplication

Reporting ServicesFull-Text Search

Notification Services

Integration Services

SQL 2005 Top 30 – 管理• Database Mirroring• Online Indexing Operations• New Integrated Toolset• Snapshot Isolation• Data Partitioning• Mirrored Backups• Online Restore• Fast Recovery• Dedicated Administrator Connection• Replication Enhancements

智慧智慧開發開發管理管理

B IB I開發開發管理管理

SQL 2005 Top 30 – 開發• .NET Framework Hosting• XML Technologies• ADO.NET 2.0• Transact-SQL Enhancements• SQL Service Broker• Notification Services• Web Services• XQuery Support• Full-Text Search Enhancements• Security Enhancements



SQL 2005 Top 30 – 商業智慧• Analysis Services

• SSIS (Data Transformation Services)

• Data Mining

• Reporting Services

• Clustering Support

• Key Performance Indicators

• Scalability and Performance

• One-Click Cube

• Architecture Enhancements

• Integration with the Microsoft Office System



SQL Server 2000 Silver Bullets

FeatureSQL Server 2000Standard Edition

SQL Server 2000Enterprise Edition

Number of CPUs 4 OS Maximum

Memory 2 GB OS Maximum

Failover Clustering

64-bit Support

Log Shipping

Distributed Partitioned Views

Parallel Operations for SMP Systems

Distributed Partitioned Cubes

SQL Server 2005 Changes

FeatureSQL Server 2000Standard Edition

SQL Server 2005 Standard Edition

Number of CPUs 44+

multi-core technology

Memory 2 GB OS Maximum

Failover Clustering 2-node Only

64-bit Support

Log Shipping Database Mirroring

Distributed Partitioned Views

Parallel Operations for SMP Systems

Some

Distributed Partitioned Cubes

Feature Standard Edition Enterprise Edition

Number of CPUs 4 64

Memory OS Maximum OS Maximum

Multi-Instance Support 16 50

Dynamic AWE Memory Management

Database Snapshot

Scalable Shared Databases

Indexed Views

Parallel Index Operations

Parallel Consistency Checks (DBCC)

Enhanced Read-ahead and Scan (Super Scan)

Up to 4 CPUsUp to 4 CPUs

• Single CPU index operationsSingle CPU index operations• Manual index views usageManual index views usage

No Scale-upNo Scale-up Limited scale outLimited scale out

• Service Broker Service Broker OnlyOnly

• Multiple CPU index Multiple CPU index operationsoperations

• Automatic index view Automatic index view usageusage

Scale out includedScale out included

• Service Broker Service Broker • Peer-to-Peer Peer-to-Peer

replicationreplication

Scale-up includedScale-up included

PartitioningPartitioning

Up to 64 CPUsUp to 64 CPUs

HardwareHardware

DatabaseDatabase ScaleScale

Database Database PerformanPerformancece

Standard Standard EditionEdition

Enterprise Enterprise EditionEdition

Feature Standard EditionEnterprise

Edition

Failover Clustering 2-nodes Only Up to 8 nodes

Database Mirroring Safety FULL Only All Modes

Database Snapshot

Fast Recovery

Online Index Operations

Online Page and File Restore

Parallel Index Operations Updateable Distributed Partitioned

Views

Table and Index Partitioning

• SQL Server 2000: Database is available after Undo completes

• SQL Server 2005 Standard Edition: Database is available when Undo begins

• SQL Server 2005 Enterprise Edition: Database recovery leverages all CPU’s Faster Recovery

UndoRedo

Database is Available!

UndoRedo


UndoRedo


Protect from User & Logical Errors

Recover from user & logical errors

Prevent user errors

Decrease Maintenance Downtime

Online Service Pack Install & Upgrades

Online Maintenance Operations

Recovery from Failures

Disaster Recovery

Recovery from HW/SW Failure

Recovery from Database Failure

Database Snapshots

DDL Triggers

DB Mirroring, Clustering & Peer-to-Peer Replication

Online Index Operations

Database Mirroring

Mirroring, Clustering & Replication

Fast Recovery, Online Restore

SQL Server Management Studio Reports

• Server Memory Consumption

• DBCC DropCleanBuffers• Database

Disk Usage• Service Broker

Service Broker Statistics• Logins

Login Statistics• Management

Number of Errors

Disk Usage Report

SQL Server Backup TypesBackup Type Description

Full All data files and part of the transaction log

Transaction log

Any database changes recorded in the log files

Tail-log The active portion of the log

DifferentialThe parts of the database that have changed

since the last full database backup

File / Filegroup

Specified files or filegroups

PartialThe primary filegroup, every read/write

filegroup, and any specified read-only filegroups

Copy-onlyThe database or log (without affecting the

backup sequence)

What Are Recovery Models?

Recovery Model Description

SimpleUses full or differential copies of

the database. Truncates the transaction logs.

FullIncludes both database backups

and transaction log backups.

Bulk-logged

Includes both database and transaction log backups, but uses less log space for some operations.

What Is a File or Filegroup Backup Strategy?

• Use file or filegroups if:

Database is very largeA full backup would take too long

• Back up transaction logs separately• Can be complex to manage

Sunday Monday Tuesday Wednesday

Datafile 1

Data file 2

Data file 3

How to Perform a Piecemeal Restore

• Restore a database in stages based on filegroups

Start with primary filegroupContinue with secondary filegroups

• Each filegroup comes online as it is restored

• Transactions involving filegroups not yet restored will hold locks until rollback can complete

Overview of Online Restore Operations

DatabaseDatabase

PrimaryPrimaryFilegroupFilegroup

Filegroup AFilegroup A

Filegroup BFilegroup B

File unavailable, filegroup offline

All files available, filegroup online

Primary filegroup online, database available

Restoringfile

How to Restore a Damaged Page

Identify ID of damaged page

Restore page from a full or differential backup

Use PAGE clause to specify pages to restore

Specify NORECOVERY

Restore transaction logs

Backup transaction log tail

Restore transaction log tail

Identify ID of damaged page

Restore page from a full or differential backup

Use PAGE clause to specify pages to restore

Specify NORECOVERY

Restore transaction logs

Backup transaction log tail

Restore transaction log tail

11

33

44

55

22

RESTORE DATABASE AdventureWorksPAGE = '1:610'FROM AWBackWITH NORECOVERY

RESTORE DATABASE AdventureWorksPAGE = '1:610'FROM AWBackWITH NORECOVERY

What Is a Database Snapshot?

12:00 Snapshot

• Read-only, consistent view of a database at a specified point in time

• Useful as test or development database, or for reporting

• Must exist on same server as source database

How Database Snapshots Work

Source DB Snapshot DB

Copy-On-Write (first time only)

SELECT …SELECT …

SELECT …SELECT …UPDATE …UPDATE …

How to Use a Database Snapshot to Recover Data

Scenario Example Code / Steps

Undeleterows

Undoingan update

Recoveringa droppedobject

11 Script the object in the database snapshot

INSERT INTO Production.WorkOrderRoutingSELECT * FROM AdventureWorks_dbsnapshot_1800.Prod.WorkOrderRouting

INSERT INTO Production.WorkOrderRoutingSELECT * FROM AdventureWorks_dbsnapshot_1800.Prod.WorkOrderRouting

UPDATE HR.DepartmentSET Name = ( SELECT Name FROM AdventureWorks_dbsnapshot_1800.HR.Department WHERE DepartmentID = 1)WHERE DepartmentID = 1

UPDATE HR.DepartmentSET Name = ( SELECT Name FROM AdventureWorks_dbsnapshot_1800.HR.Department WHERE DepartmentID = 1)WHERE DepartmentID = 1

Caution: Not a substitute for a comprehensive backup and restore strategy

Execute the script in the source database22

Repopulate the object (if appropriate)33

• Read-only, consistent copy of database• Very fast to create• Can be created for any database

Production databases Instant standby databases with

Database Mirroring• Supports scale-out and high availability

scenarios Great solution for reporting/read-only

applications Safeguarding data against application

and human error• Rollback to a snapshot to correct the error

伺服器調校伺服器

調校

交易鎖定交易鎖定

索引最佳化索引最佳化

查詢最佳化查詢最佳化

資料庫結構設計資料庫結構設計

效能最佳化模型

資料庫設計迷思

• 到底需不需要正規化呢？• 資料庫交易記錄檔應該設多大？• 索引到底該如何建才正確？ • 要如何才能避免資料被 Lock 呢？

正規化（ Normalization ）

• 正規化（ Normalization ）的目的是減少「重複累贅的資料」。

• 一般只會實施到第三正規化。• 優點 -- 方便維護及修改。• 缺點 -- 查詢資料時需要 Join 較多的資料表才能得到

所需資料，因此回應時間加長。• 檢視標準 -- 每次存取資料時均要 Join 六、七個資料

表，回應時間加長，既表示過渡正規化。

應用程式特性（一）• 線上交易（ OLTP ）應用程式

「多人同時上線」 (Concurrency)「頻繁」的從事「小量交易」使用指令 Select/Insert/Update/ Delete 主要 workload

• Reads, writes可能問題

• Locking ， Blocking ， Disk I/O ， CPU ， Memory

可能的解決方案• 可以做正規化• 刪除不必要的索引• 使用 Transaction Isolation Level Snapshot• 非同步處理（ Asynchronous data access)

應用程式特性（二）• Decision Support System （ DSS ）應用程式

OLAPData Mining報表製作（ Reporting ）

• 特性讀取大量資料，然後作彙總計算使用 Select主要 workload

• Reads可能問題

• 大量硬碟 I/O • 資料碎裂

• 可能的解決方案可以做非正規化建立索引索引重整（ Index Rebuild ）

索引最佳化• 建在單一欄位上的非叢集式索引，百分之九十的情況

下， Query Analyzer 會選擇使用 Table Scan ，而不會使用該索引。

• 資料經過一段時間，新增 / 修改 / 刪除之後，會產生碎裂，應執行索引重整（類似磁碟機重整）。

• 作索引重整（ Index Rebuild ）對提升報表製作（ Reporting ）應用程式效能有幫助。

Default Trace• 佔資源少• 預設路徑 C:\Program Files\Microsoft SQL Server\ MSSQL.1\

MSSQL\LOG• 預設追蹤事件約三十多項，如：

Audit Addlogin EventAudit Login FailedAudit Backup/Restore EventData File Auto GrowDatabase Mirroring State ChangeObject: CreatedObject: AlteredObject: DeletedServer Memory Change

Disable Default TraceSP_CONFIGURE 'show advanced options',1

go

RECONFIGURE

GO

SP_CONFIGURE 'DEFAULT TRACE ENABLED',1

GO

RECONFIGURE

GO

透過 DMV 及 DMF 檢視效能瓶頸

• SQL Server 2000 ，必需得靠 Profiler 記錄的 trace file （追蹤記錄檔）。

• SQL Server 2005 中新增許多系統檢視及系統函數Dynamic Management View （ DMV ）Dynamic Management Function （ DMF ）。

Dynamic Management View （ DMV ） Dynamic

Management Function （ DMF ）

• 與系統資料表不同， DMV 不會存檔。 • DMV 中的紀錄會隨著資料庫的使用狀態而改變• DMV/DMF 的命名規則

命名一定是 dm_* DMV 及 DMF 均屬於 sys 這個 schema 用時一定要寫 two-part name 或 three-part name ，如 sys.dm_*

Dynamic Management View （ DMV ） Dynamic Management Function （ DMF ）• DMV/DMF 可大分為兩類，伺服器層級及元件層級 • 伺服器層級（ Server Level ）

sys.dm_exec_*• 記錄使用者程式碼執行狀態。

sys.dm_os_*• 記錄伺服器層級系統相關資訊，例如記憶體， locking ，及排程

等。sys.dm_tran_*

• 記錄 Transactions 及 isolation 相關資訊。sys.dm_io_*

• 記錄網路及硬碟上的 I/O 。sys.dm_db_*

• 記錄資料庫及其相關物件。

Dynamic Management View （ DMV ） Dynamic Management Function （ DMF ）• 元件層級（ Component Level)

sys.dm_repl_*• 記錄資料庫複寫。

sys.dm_broker_*• 記錄 Service Broker 相關資訊。

sys.dm_fts_*• 記錄全文檢索相關資訊。

sys.dm_qn_*• 記錄 Query Notifications 相關資訊。

sys.dm_clr_*• 記錄 CLR 程式碼執行相關資訊。

sys.dm_exec_requests

• 可檢查伺服器上各 Session 執行狀態

Select scheduler_id, session_id, status, command, wait_type, wait_resource, percent_complete, cpu_time

from sys.dm_exec_requests where session_id > 50

Runnable Queue

CPU Pressure （處理器瓶頸）

• Runnable Queue -- Status 欄位顯示為 runnable ，表示這些 session 正在等待執行

• 這一類的等待表示一切資源均已完備，只等待 CPU 處理，稱之為 Signal Waits 。

• 計算 Signal Waits 的時間，即可知道處理器是否產生瓶頸，此一項評量標準稱為 CPU Pressure 。

Resources Waits

• Waiter List （等待清單） -- Status 欄位顯示為suspended

• 這一類的等待稱為 Resources Waits ，表示在等待資源（ Resources ），至於是哪種資源，可能是記憶體，或是資料被 Block 住，或是 Disk I/O ，…等原因，可參考wait_type （等待種類）欄位

• wait_type -- 在 SQL Server 2000 約有 76 種， SQL Server 2005 約有 192 種

Resources Waits

sys.dm_os_waiting_tasks

• 提供 wait 相關資訊

sys.dm_os_wait_stats

• 計算出 signal_wait_time_ms 和 resource_wait_time_ms ，並將之轉換成百分比

Select signal_wait_time_ms=sum(signal_wait_time_ms),'%signal waits' = cast(100.0 * sum(signal_wait_time_ms) / sum (wait_time_ms) as numeric(20,2)),resource_wait_time_ms=sum(wait_time_ms - signal_wait_time_ms),'%resource waits'= cast(100.0 * sum(wait_time_ms - signal_wait_time_ms) / sum (wait_time_ms) as numeric(20,2))

From sys.dm_os_wait_stats

sys.dm_os_wait_stats

sys.dm_exec_sql_text(sql_handle)

• 此 DMF 傳回目前伺服器上正在執行的指令 select r.session_id, status ,substring(qt.text,r.statement_start_offset/2,

(case when r.statement_end_offset = -1 then len(convert(nvarchar(max), qt.text)) * 2 else r.statement_end_offset end -

r.statement_start_offset)/2) as query_text --- 傳回目前正在執行指令,qt.dbid,qt.objectid,r.cpu_time,r.total_elapsed_time,r.reads,r.writes,r.logical_reads,r.scheduler_id

from sys.dm_exec_requests rcross apply sys.dm_exec_sql_text(sql_handle) as qtwhere r.session_id > 50order by r.scheduler_id, r.status, r.session_id

Object Execution Statics

Top Query By Total CPU Time

sys.dm_exec_query_stats

• Top 50 statements by Avg CPU TimeSELECT TOP 50 qs.total_worker_time/qs.execution_count as [Avg CPU Time], SUBSTRING(qt.text,qs.statement_start_offset/2,

(case when qs.statement_end_offset = -1 then len(convert(nvarchar(max), qt.text)) * 2 else qs.statement_end_offset end -

qs.statement_start_offset)/2) as query_text,qt.dbid, dbname=db_name(qt.dbid),qt.objectid

FROM sys.dm_exec_query_stats qscross apply sys.dm_exec_sql_text(qs.sql_handle) as qtORDER BY [Avg CPU Time] DESC

Load balancing

Applicationserver

Update and read load balancingUpdate and read load balancing

Read load balancingRead load balancing

Load balancing

Applicationserver

Implementing Distributed Load Balancing

Read request

Write request

User traffic

Replicated data

Implementing Distributed High Availability

• Synchronizing nodes

• Peer-to-peer replication topologies

• Implementing a peer-to-peer replication topology

Log Reader Agent

DistributionAgent

SydneySydney

Log Reader Agent

DistributionAgent

LondonLondon

Log Reader Agent

DistributionAgent

New YorkNew York

How to configure Peer-to-Peer Replication?

• 在三台 SQL Instance 上各建一個 Database ，均包含相同的 Table

• 在其中一台新增一個 Publication （注意不要勾選 Create a snapshot immediately and keep the snapshot available to initialize subscriptions

• 在 Publication 上按右鍵 propertysubscription options 將 Allow peer-to-peer subscriptions 改為True

• 在 Publication 上按右鍵選擇 Configure Peer-to-peer Topology 選擇要加入 Peer 的 Server 及 Database

Transaction Isolation Levels

• Database Engine isolation Levels:

• Read Uncommitted (Dirty Read)

• Read Committed

• Repeatable Read

• Snapshot

• Serializable

Guidelines to reduce Locking and Blocking

• Keep logical transactions short

• Avoid cursors

• Use efficient and well-indexed queries

• Use the minimum transaction isolation level required

• Keep triggers to a minimum

Database Roles and Topology for Database Mirroring

Witness Server (Optional)

Principal Server (Online database)

Mirror Server (Standby database)

Client Session

Database Mirroring Session

What Is Database Mirroring?

• Alternative to failover clustering

• Mirror ServerProvides a hot standby

• Witness ServerMonitors the primary and mirror database servers

• Client redirectionAutomatic client redirection

Options For Database Mirroring Configuration

ModeAutomatic Failover

Full Protection from Data Loss

High Availability

同步有見證伺服器High Protection同步無見證伺服器

High Performance

非同步有見證伺服器

How to Prepare Servers for Database Mirroring

Create mirroring endpoints and loginsCreate mirroring endpoints and logins11

Back up database and restore on mirror serverBack up database and restore on mirror server33

Copy server-level resourcesCopy server-level resources44

Set recovery model to FULLSet recovery model to FULL22

sql server 2005 資料庫管理達人一日體驗營

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