Genral question on Archivelog & redolog

Dear All,
This is just a imaginary question…Your response to this will clear my understanding to a great extent.
I have a database “ORCL” and have Archive log enabled in oracle 10g. Let us assume that the archiving happens every 1 hour to disk and gets backed up every 1 hour. At 23:59 hours something strange happens and puts me in a situation to recover the database to the time 23:58 hour. But I only have the archive logs/backup till 23:00 hour. However there will be modified changes in redo log files from 23:00 to 23:58.In this scenario how to get the data to the recent point till 23:58.
Thanks in advance
Kamesh

Kamesh wrote:
Dear All,
This is just a imaginary question…Your response to this will clear my understanding to a great extent.
I have a database “ORCL” and have Archive log enabled in oracle 10g. Let us assume that the archiving happens every 1 hour to disk and gets backed up every 1 hour. At 23:59 hours something strange happens and puts me in a situation to recover the database to the time 23:58 hour. But I only have the archive logs/backup till 23:00 hour. However there will be modified changes in redo log files from 23:00 to 23:58.In this scenario how to get the data to the recent point till 23:58.
So you do have the archivelogs till 23:00 hours and the rest of the redo is in the online logs, is it? You are going to do the recovery with until time option . It would be an incomplete recovery.
HTH
Aman....

Similar Messages

Genral question on equipment and functional location....

hi,
what I have to learn on functional location and equipment other than the below concepts
creating euipment and installation,
and customizing like screen sequences of Fun. locations and equipment....
and field selection for functional locations and equipment...
stucture indicator for F locations...
category of functional locations and equipment...
becoz i am going to allot for a project more over this is my first proect.......
Plz help me.........,
thanks in before
gunnu

Hi,
Under Equipments:
1. Equipment Master Data
2. Equipment BoM
3. Measuring Point
4. Serial Number Assignment
5. Installation / Dismantling with Superior Equipment / Functional Location
6. PRT as Equipment (Production Resource Tools)
7. Fleet Equipments
You can find all the helps in Help.sap.com under Plant Maintenance module. Just have a search in google.
[Equipments & Technical Objects|http://help.sap.com/saphelp_erp60_sp/helpdata/en/b0/df293581dc1f79e10000009b38f889/frameset.htm]
Regards,
Maheswaran.
Edited by: Maheswaran.K on Apr 28, 2011 1:10 PM

Oracle Performance tunning genral question

Hi,
Below is the list of Areas of Oracle db for which tunning activities are done. You are invited to comment to it weather this is complete list or need some addition or deletion. As I'm learning PT for Oracle now a days, therefore I want to expand my knowledge by sharing what I'm learning and what I need to learn.
So comment with Open hearts on it. Espically from experts and Gurus.
Here is the List
1-Planning for Performance, include Storage consideration( Weather it is SAN, NAS, DAS), Network planning and host OS planning with proper configuration for running Oracle.
2-Database desining (Not under-Normalized and not Over-Normalized with proper usage of Indexes, views and Stored Procedures)
3- Instance tunning (Memory structure + B.g Processes)
4- Session tunning.
5- Segment Space tunning.
6- SQL tunning.
This is what uptill what I've learned. If it needs addition kindly tell me what are these. Please also provide me links(good and precise one) for PT tutorials on web.Also note that I'm discussing this w.r.t Single instance non-rac db.
Looking for Good sugessions
Regards,
Abbasi

Hello,
This is the oracle course contents:
Contents
Preface
1 Introduction
Course Objectives 1-2
Organization 1-3
Agenda 1-4
What Is Not Included 1-6
Who Tunes? 1-7
What Does the DBA Tune? 1-8
How to Tune 1-10
Tuning Methodology 1-11
Effective Tuning Goals 1-13
General Tuning Session 1-15
Summary 1-17
2 Basic Tuning Tools
Objectives 2-2
Performance Tuning Diagnostics 2-3
Performance Tuning Tools 2-4
Tuning Objectives 2-5
Top Wait Events 2-6
DB Time 2-7
CPU and Wait Time Tuning Dimensions 2-8
Time Model: Overview 2-9
Time Model Statistics Hierarchy 2-10
Time Model Example 2-12
Dynamic Performance Views 2-13
Dynamic Performance Views: Usage Examples 2-14
Dynamic Performance Views: Considerations 2-15
Statistic Levels 2-16
Statistics and Wait Events 2-18
System Statistic Classes 2-19
Displaying Statistics 2-20
Displaying SGA Statistics 2-22
Wait Events 2-23
Using the V$EVENT_NAME View 2-24
Wait Classes 2-25
Displaying Wait Event Statistics 2-26
Oracle Internal & Oracle Academy Use Only
iv
Commonly Observed Wait Events 2-28
Using the V$SESSION_WAIT View 2-29
Precision of System Statistics 2-31
Using Features of the Packs 2-32
Accessing the Database Home Page 2-34
Enterprise Manager Performance Pages 2-35
Viewing the Alert Log 2-37
Using Alert Log Information as an Aid in Tuning 2-38
User Trace Files 2-40
Background Processes Trace Files 2-41
Summary 2-42
Practice 2 Overview: Using Basic Tools 2-43
3 Using Automatic Workload Repository
Objectives 3-2
Automatic Workload Repository: Overview 3-3
Automatic Workload Repository Data 3-4
Workload Repository 3-5
Database Control and AWR 3-6
AWR Snapshot Purging Policy 3-7
AWR Snapshot Settings 3-8
Manual AWR Snapshots 3-9
Managing Snapshots with PL/SQL 3-10
Generating AWR Reports in EM 3-11
Generating AWR Reports in SQL*Plus 3-12
Reading the AWR Report 3-13
Snapshots and Periods Comparisons 3-14
Compare Periods: Benefits 3-15
Compare Periods: Results 3-16
Compare Periods: Report 3-17
Compare Periods: Load Profile 3-18
Compare Periods: Top Events 3-19
Summary 3-20
Practice 3 Overview: Using AWR-Based Tools 3-21
4 Defining Problems
Objectives 4-2
Defining the Problem 4-3
Limit the Scope 4-4
Setting the Priority 4-5
Top Wait Events 4-6
Oracle Internal & Oracle Academy Use Only
v
Setting the Priority: Example 4-7
Top SQL Reports 4-8
Common Tuning Problems 4-9
Tuning Life Cycle Phases 4-11
Tuning During the Life Cycle 4-12
Application Design and Development 4-13
Testing: Database Configuration 4-14
Deployment 4-15
Production 4-16
Migration, Upgrade, and Environment Changes 4-17
ADDM Tuning Session 4-18
Performance Versus Business Requirements 4-19
Performance Tuning Resources 4-20
Filing a Performance Service Request 4-21
RDA Report 4-22
Monitoring and Tuning Tool: Overview 4-23
Summary 4-25
Practice 4 Overview: Identifying the Problem 4-26
5 Using Metrics and Alerts
Objectives 5-2
Metrics, Alerts, and Baselines 5-3
Limitation of Base Statistics 5-4
Typical Delta Tools 5-5
Oracle Database 11g Solution: Metrics 5-6
Benefits of Metrics 5-7
Viewing Metric History Information 5-8
Using EM to View Metric Details 5-9
Statistic Histograms 5-10
Histogram Views 5-11
Server-Generated Alerts 5-12
Database Control Usage Model 5-13
Setting Thresholds 5-14
Creating and Testing an Alert 5-15
Metric and Alert Views 5-16
View User-Defined SQL Metrics 5-17
Create User-Defined SQL Metrics 5-18
View User-Defined Host Metrics 5-19
Create User-Defined Host Metrics 5-20
Summary 5-21
Practice Overview 5: Working with Metrics 5-22
Oracle Internal & Oracle Academy Use Only
vi
6 Baselines
Objectives 6-2
Comparative Performance Analysis with AWR Baselines 6-3
Automatic Workload Repository Baselines 6-4
Moving Window Baseline 6-5
Baselines in Performance Page Settings 6-6
Baseline Templates 6-7
AWR Baselines 6-8
Creating AWR Baselines 6-9
Single AWR Baseline 6-10
Creating a Repeating Baseline Template 6-11
Managing Baselines with PL/SQL 6-12
Generating a Baseline Template for a Single Time Period 6-13
Creating a Repeating Baseline Template 6-14
Baseline Views 6-15
Performance Monitoring and Baselines 6-17
Defining Alert Thresholds Using a Static Baseline 6-19
Using EM to Quickly Configure Adaptive Thresholds 6-20
Changing Adaptive Threshold Settings 6-22
Summary 6-23
Practice 6: Overview Using AWR Baselines 6-24
7 Using AWR-Based Tools
Objectives 7-2
Automatic Maintenance Tasks 7-3
Maintenance Windows 7-4
Default Maintenance Plan 7-5
Automated Maintenance Task Priorities 7-6
Tuning Automatic Maintenance Tasks 7-7
ADDM Performance Monitoring 7-8
ADDM and Database Time 7-9
DBTime-Graph and ADDM Methodology 7-10
Top Performance Issues Detected 7-12
Database Control and ADDM Findings 7-13
ADDM Analysis Results 7-14
ADDM Recommendations 7-15
Database Control and ADDM Task 7-16
Changing ADDM Attributes 7-17
Retrieving ADDM Reports by Using SQL 7-18
Active Session History: Overview 7-19
Active Session History: Mechanics 7-20
Oracle Internal & Oracle Academy Use Only
vii
ASH Sampling: Example 7-21
Accessing ASH Data 7-22
Dump ASH to File 7-23
Analyzing the ASH Data 7-24
Generating ASH Reports 7-25
ASH Report Script 7-26
ASH Report: General Section 7-27
ASH Report Structure 7-28
ASH Report: Activity Over Time 7-29
Summary 7-30
Practice 7 Overview: Using AWR-Based Tools 7-31
8 Monitoring an Application
Objectives 8-2
What Is a Service? 8-3
Service Attributes 8-4
Service Types 8-5
Creating Services 8-6
Managing Services in a Single-Instance Environment 8-7
Everything Switches to Services 8-8
Using Services with Client Applications 8-9
Using Services with the Resource Manager 8-10
Services and Resource Manager with EM 8-11
Services and the Resource Manager: Example 8-12
Using Services with the Scheduler 8-13
Services and the Scheduler with EM 8-14
Services and the Scheduler: Example 8-16
Using Services with Parallel Operations 8-17
Using Services with Metric Thresholds 8-18
Changing Service Thresholds by Using EM 8-19
Services and Metric Thresholds: Example 8-20
Service Aggregation and Tracing 8-21
Top Services Performance Page 8-22
Service Aggregation Configuration 8-23
Service Aggregation: Example 8-24
Client Identifier Aggregation and Tracing 8-25
trcsess Utility 8-26
Service Performance Views 8-27
Summary 8-29
Practice 8 Overview: Using Services 8-30
Oracle Internal & Oracle Academy Use Only
viii
9 Identifying Problem SQL Statements
Objectives 9-2
SQL Statement Processing Phases 9-3
Parse Phase 9-4
SQL Storage 9-5
Cursor Usage and Parsing 9-6
SQL Statement Processing Phases: Bind 9-8
SQL Statement Processing Phases: Execute and Fetch 9-9
Processing a DML Statement 9-10
COMMIT Processing 9-12
Role of the Oracle Optimizer 9-13
Identifying Bad SQL 9-15
TOP SQL Reports 9-16
What Is an Execution Plan? 9-17
Methods for Viewing Execution Plans 9-18
Uses of Execution Plans 9-19
DBMS_XPLAN Package: Overview 9-20
EXPLAIN PLAN Command 9-22
EXPLAIN PLAN Command: Example 9-23
EXPLAIN PLAN Command: Output 9-24
Reading an Execution Plan 9-25
Using the V$SQL_PLAN View 9-26
V$SQL_PLAN Columns 9-27
Querying V$SQL_PLAN 9-28
V$SQL_PLAN_STATISTICS View 9-29
Querying the AWR 9-30
SQL*Plus AUTOTRACE 9-32
Using SQL*Plus AUTOTRACE 9-33
SQL*Plus AUTOTRACE: Statistics 9-34
SQL Trace Facility 9-35
How to Use the SQL Trace Facility 9-37
Initialization Parameters 9-38
Enabling SQL Trace 9-40
Disabling SQL Trace 9-41
Formatting Your Trace Files 9-42
TKPROF Command Options 9-43
Output of the TKPROF Command 9-45
TKPROF Output with No Index: Example 9-50
TKPROF Output with Index: Example 9-51
Generate an Optimizer Trace 9-52
Oracle Internal & Oracle Academy Use Only
ix
Summary 9-53
Practice Overview 9: Using Execution Plan Utilities 9-54
10 Influencing the Optimizer
Objectives 10-2
Functions of the Query Optimizer 10-3
Selectivity 10-5
Cardinality and Cost 10-6
Changing Optimizer Behavior 10-7
Using Hints 10-8
Optimizer Statistics 10-9
Extended Statistics 10-10
Controlling the Behavior of the Optimizer with Parameters 10-11
Enabling Query Optimizer Features 10-13
Influencing the Optimizer Approach 10-14
Optimizing SQL Statements 10-15
Access Paths 10-16
Choosing an Access Path 10-17
Full Table Scans 10-18
Row ID Scans 10-20
Index Operations 10-21
B*Tree Index Operations 10-22
Bitmap Indexes 10-23
Bitmap Index Access 10-24
Combining Bitmaps 10-25
Bitmap Operations 10-26
Join Operations 10-27
Join Methods 10-28
Nested Loop Joins 10-29
Hash Joins 10-31
Sort-Merge Joins 10-32
Join Performance 10-34
How the Query Optimizer Chooses Execution Plans for Joins 10-35
Sort Operations 10-37
Tuning Sort Performance 10-38
Reducing the Cost 10-39
Index Maintenance 10-40
Dropping Indexes 10-42
Creating Indexes 10-43
SQL Access Advisor 10-44
Table Maintenance for Performance 10-45
Oracle Internal & Oracle Academy Use Only
x
Table Reorganization Methods 10-46
Summary 10-47
Practice 10 Overview: Influencing the Optimizer 10-48
11 Using SQL Performance Analyzer
Objectives 11-2
Real Application Testing: Overview 11-3
Real Application Testing: Use Cases 11-4
SQL Performance Analyzer: Process 11-5
Capturing the SQL Workload 11-7
Creating a SQL Performance Analyzer Task 11-8
SQL Performance Analyzer: Tasks 11-9
Optimizer Upgrade Simulation 11-10
SQL Performance Analyzer Task Page 11-11
Comparison Report 11-12
Comparison Report SQL Detail 11-13
Tuning Regressing Statements 11-14
Preventing Regressions 11-16
Parameter Change Analysis 11-17
Guided Workflow Analysis 11-18
SQL Performance Analyzer: PL/SQL Example 11-19
SQL Performance Analyzer: Data Dictionary Views 11-21
Summary 11-22
Practice 11: Overview 11-23
12 SQL Performance Management
Objectives 12-2
Maintaining SQL Performance 12-3
Maintaining Optimizer Statistics 12-4
Automated Maintenance Tasks 12-5
Statistic Gathering Options 12-6
Setting Statistic Preferences 12-7
Restore Statistics 12-9
Deferred Statistics Publishing: Overview 12-10
Deferred Statistics Publishing: Example 12-12
Automatic SQL Tuning: Overview 12-13
SQL Statement Profiling 12-14
Plan Tuning Flow and SQL Profile Creation 12-15
SQL Tuning Loop 12-16
Using SQL Profiles 12-17
SQL Tuning Advisor: Overview 12-18
Oracle Internal & Oracle Academy Use Only
xi
Using the SQL Tuning Advisor 12-19
SQL Tuning Advisor Options 12-20
SQL Tuning Advisor Recommendations 12-21
Using the SQL Tuning Advisor: Example 12-22
Using the SQL Access Advisor 12-23
View Recommendations 12-25
View Recommendation Details 12-26
SQL Plan Management: Overview 12-27
SQL Plan Baseline: Architecture 12-28
Loading SQL Plan Baselines 12-30
Evolving SQL Plan Baselines 12-31
Important Baseline SQL Plan Attributes 12-32
SQL Plan Selection 12-34
Possible SQL Plan Manageability Scenarios 12-36
SQL Performance Analyzer and SQL Plan Baseline Scenario 12-37
Loading a SQL Plan Baseline Automatically 12-38
Purging SQL Management Base Policy 12-39
Enterprise Manager and SQL Plan Baselines 12-40
Summary 12-41
Practice 12: Overview Using SQL Plan Management 12-42
13 Using Database Replay
Objectives 13-2
Using Database Replay 13-3
The Big Picture 13-4
System Architecture: Capture 13-5
System Architecture: Processing the Workload 13-7
System Architecture: Replay 13-8
Capture Considerations 13-9
Replay Considerations: Preparation 13-10
Replay Considerations 13-11
Replay Options 13-12
Replay Analysis 13-13
Database Replay Workflow in Enterprise Manager 13-15
Capturing Workload with Enterprise Manager 13-16
Capture Wizard: Plan Environment 13-17
Capture Wizard: Options 13-18
Capture Wizard: Parameters 13-19
Viewing Capture Progress 13-20
Viewing Capture Report 13-21
Export Capture AWR Data 13-22
Oracle Internal & Oracle Academy Use Only
xii
Viewing Workload Capture History 13-23
Processing Captured Workload 13-24
Using the Preprocess Captured Workload Wizard 13-25
Using the Replay Workload Wizard 13-26
Replay Workload: Prerequisites 13-27
Replay Workload: Choose Initial Options 13-28
Replay Workload: Customize Options 13-29
Replay Workload: Prepare Replay Clients 13-30
Replay Workload: Client Connections 13-31
Replay Workload: Replay Started 13-32
Viewing Workload Replay Progress 13-33
Viewing Workload Replay Statistics 13-34
Packages and Procedures 13-36
Data Dictionary Views: Database Replay 13-37
Database Replay: PL/SQL Example 13-38
Calibrating Replay Clients 13-40
Summary 13-41
Practice 13: Overview 13-42
14 Tuning the Shared Pool
Objectives 14-2
Shared Pool Architecture 14-3
Shared Pool Operation 14-4
The Library Cache 14-5
Latch and Mutex 14-7
Latch and Mutex: Views and Statistics 14-9
Diagnostic Tools for Tuning the Shared Pool 14-11
AWR/Statspack Indicators 14-13
Load Profile 14-14
Instance Efficiencies 14-15
Top Waits 14-16
Time Model 14-17
Library Cache Activity 14-19
Avoid Hard Parses 14-20
Are Cursors Being Shared? 14-21
Sharing Cursors 14-23
Adaptive Cursor Sharing: Example 14-25
Adaptive Cursor Sharing Views 14-27
Interacting with Adaptive Cursor Sharing 14-28
Avoiding Soft Parses 14-29
Sizing the Shared Pool 14-30
Oracle Internal & Oracle Academy Use Only
xiii
Shared Pool Advisory 14-31
Shared Pool Advisor 14-33
Avoiding Fragmentation 14-34
Large Memory Requirements 14-35
Tuning the Shared Pool Reserved Space 14-37
Keeping Large Objects 14-39
Data Dictionary Cache 14-41
Dictionary Cache Misses 14-42
SQL Query Result Cache: Overview 14-43
Managing the SQL Query Result Cache 14-44
Using the RESULT_CACHE Hint 14-46
Using the DBMS_RESULT_CACHE Package 14-47
Viewing SQL Result Cache Dictionary Information 14-48
SQL Query Result Cache: Considerations 14-49
UGA and Oracle Shared Server 14-50
Large Pool 14-51
Tuning the Large Pool 14-52
Summary 14-53
Practice Overview 14: Tuning the Shared Pool 14-54
15 Tuning the Buffer Cache
Objectives 15-2
Oracle Database Architecture 15-3
Buffer Cache: Highlights 15-4
Database Buffers 15-5
Buffer Hash Table for Lookups 15-6
Working Sets 15-7
Tuning Goals and Techniques 15-9
Symptoms 15-11
Cache Buffer Chains Latch Contention 15-12
Finding Hot Segments 15-13
Buffer Busy Waits 15-14
Calculating the Buffer Cache Hit Ratio 15-15
Buffer Cache Hit Ratio Is Not Everything 15-16
Interpreting Buffer Cache Hit Ratio 15-17
Read Waits 15-19
Free Buffer Waits 15-21
Solutions 15-22
Sizing the Buffer Cache 15-23
Buffer Cache Size Parameters 15-24
Dynamic Buffer Cache Advisory Parameter 15-25
Oracle Internal & Oracle Academy Use Only
xiv
Buffer Cache Advisory View 15-26
Using the V$DB_CACHE_ADVICE View 15-27
Using the Buffer Cache Advisory with EM 15-28
Caching Tables 15-29
Multiple Buffer Pools 15-30
Enabling Multiple Buffer Pools 15-32
Calculating the Hit Ratio for Multiple Pools 15-33
Multiple Block Sizes 15-35
Multiple Database Writers 15-36
Multiple I/O Slaves 15-37
Use Multiple Writers or I/O Slaves 15-38
Private Pool for I/O Intensive Operations 15-39
Automatically Tuned Multiblock Reads 15-40
Flushing the Buffer Cache (for Testing Only) 15-41
Summary 15-42
Practice 15: Overview Tuning the Buffer Cache 15-43
16 Tuning PGA and Temporary Space
Objectives 16-2
SQL Memory Usage 16-3
Performance Impact 16-4
Automatic PGA Memory 16-5
SQL Memory Manager 16-6
Configuring Automatic PGA Memory 16-8
Setting PGA_AGGREGATE_TARGET Initially 16-9
Monitoring SQL Memory Usage 16-10
Monitoring SQL Memory Usage: Examples 16-12
Tuning SQL Memory Usage 16-13
PGA Target Advice Statistics 16-14
PGA Target Advice Histograms 16-15
Automatic PGA and Enterprise Manager 16-16
Automatic PGA and AWR Reports 16-17
Temporary Tablespace Management: Overview 16-18
Temporary Tablespace: Best Practice 16-19
Configuring Temporary Tablespace 16-20
Temporary Tablespace Group: Overview 16-22
Temporary Tablespace Group: Benefits 16-23
Creating Temporary Tablespace Groups 16-24
Maintaining Temporary Tablespace Groups 16-25
View Tablespace Groups 16-26
Monitoring Temporary Tablespace 16-27
Oracle Internal & Oracle Academy Use Only
xv
Temporary Tablespace Shrink 16-28
Tablespace Option for Creating Temporary Table 16-29
Summary 16-30
Practice Overview 16: Tuning PGA Memory 16-31
17 Automatic Memory Management
Objectives 17-2
Oracle Database Architecture 17-3
Dynamic SGA 17-4
Granule 17-5
Memory Advisories 17-6
Manually Adding Granules to Components 17-7
Increasing the Size of an SGA Component 17-8
Automatic Shared Memory Management: Overview 17-9
SGA Sizing Parameters: Overview 17-10
Dynamic SGA Transfer Modes 17-11
Memory Broker Architecture 17-12
Manually Resizing Dynamic SGA Parameters 17-13
Behavior of Auto-Tuned SGA Parameters 17-14
Behavior of Manually Tuned SGA Parameters 17-15
Using the V$PARAMETER View 17-16
Resizing SGA_TARGET 17-17
Disabling Automatic Shared Memory Management 17-18
Configuring ASMM 17-19
SGA Advisor 17-20
Monitoring ASMM 17-21
Automatic Memory Management: Overview 17-22
Oracle Database Memory Parameters 17-24
Automatic Memory Parameter Dependency 17-25
Enabling Automatic Memory Management 17-26
Monitoring Automatic Memory Management 17-27
DBCA and Automatic Memory Management 17-29
Summary 17-30
Practice 17: Overview Using Automatic Memory Tuning 17-31
Oracle Internal & Oracle Academy Use Only
xvi
18 Tuning Segment Space Usage
Objectives 18-2
Space Management 18-3
Extent Management 18-4
Locally Managed Extents 18-5
Large Extents: Considerations 18-6
How Table Data Is Stored 18-8
Anatomy of a Database Block 18-9
Minimize Block Visits 18-10
The DB_BLOCK_SIZE Parameter 18-11
Small Block Size: Considerations 18-12
Large Block Size: Considerations 18-13
Block Allocation 18-14
Free Lists 18-15
Block Space Management 18-16
Block Space Management with Free Lists 18-17
Automatic Segment Space Management 18-19
Automatic Segment Space Management at Work 18-20
Block Space Management with ASSM 18-22
Creating an Automatic Segment Space Management Segment 18-23
Migration and Chaining 18-24
Guidelines for PCTFREE and PCTUSED 18-26
Detecting Migration and Chaining 18-27
Selecting Migrated Rows 18-28
Eliminating Migrated Rows 18-29
Shrinking Segments: Overview 18-31
Shrinking Segments: Considerations 18-32
Shrinking Segments by Using SQL 18-33
Segment Shrink: Basic Execution 18-34
Segment Shrink: Execution Considerations 18-35
Using EM to Shrink Segments 18-36
Table Compression: Overview 18-37
Table Compression Concepts 18-38
Using Table Compression 18-39
Summary 18-40
19 Tuning I/O
Objectives 19-2
I/O Architecture 19-3
File System Characteristics 19-4
I/O Modes 19-5
Oracle Internal & Oracle Academy Use Only
xvii
Direct I/O 19-6
Bandwidth Versus Size 19-7
Important I/O Metrics for Oracle Databases 19-8
I/O Calibration and Enterprise Manager 19-10
I/O Calibration and the PL/SQL Interface 19-11
I/O Statistics: Overview 19-13
I/O Statistics and Enterprise Manager 19-14
Stripe and Mirror Everything 19-16
Using RAID 19-17
RAID Cost Versus Benefits 19-18
Should I Use RAID 1 or RAID 5? 19-20
Diagnostics 19-21
Database I/O Tuning 19-22
What Is Automatic Storage Management? 19-23
Tuning ASM 19-24
How Many Disk Groups per Database 19-25
Which RAID Configuration for Best Availability? 19-26
ASM Mirroring Guidelines 19-27
ASM Striping Granularity 19-28
What Type of Striping Works Best? 19-29
ASM Striping Only 19-30
Hardware RAID Striped LUNs 19-31
ASM Guidelines 19-32
ASM Instance Initialization Parameters 19-33
Dynamic Performance Views 19-34
Monitoring Long-Running Operations by Using V$ASM_OPERATION 19-36
ASM Instance Performance Diagnostics 19-37
ASM Performance Page 19-38
Database Instance Parameter Changes 19-39
ASM Scalability 19-40
Summary 19-41
20 Performance Tuning Summary
Objectives 20-2
Necessary Initialization Parameters with Little Performance Impact 20-3
Important Initialization Parameters with Performance Impact 20-4
Sizing Memory Initially 20-6
Database High Availability: Best Practices 20-7
Undo Tablespace: Best Practices 20-8
Temporary Tablespace: Best Practices 20-9
General Tablespace: Best Practices 20-11
Internal Fragmentation Considerations 20-12
Oracle Internal & Oracle Academy Use Only
xviii
Block Size: Advantages and Disadvantages 20-13
Automatic Checkpoint Tuning 20-14
Sizing the Redo Log Buffer 20-15
Sizing Redo Log Files 20-16
Increasing the Performance of Archiving 20-17
Automatic Statistics Gathering 20-19
Automatic Statistics Collection: Considerations 20-20
Commonly Observed Wait Events 20-21
Additional Statistics 20-22
Top 10 Mistakes Found in Customer Systems 20-23
Summary 20-25
Appendix A: Practices and Solutions
Appendix B: Using Statspack
Index

Genral question

Hi
I'm an SAP-BW Consultant. How should be prepared for the business objects. What will be the changes in the sap bi.
Do i need to know the Business objects. Any helpful materials to read??
Please advice on this ??

BusinessObjects and SAP - Overview
/people/ingo.hilgefort/blog/2008/02/07/businessobjects-and-sap-part-i
Crystal Reports and BI Queries
/people/ingo.hilgefort/blog/2008/02/19/businessobjects-and-sap-part-2
Crystal Reports and BI Hierarchies
/people/ingo.hilgefort/blog/2008/02/27/businessobjects-and-sap-part-3
Crystal Reports and SAP R/3`
/people/ingo.hilgefort/blog/2008/03/23/businessobjects-and-sap-part-4
Web Intelligence and SAP BI
/people/ingo.hilgefort/blog/2008/03/24/businessobjects-and-sap-part-5
Web Intelligence - Delegated Search and Delegated Measures
/people/ingo.hilgefort/blog/2008/08/27/businessobjects-and-sap-part-6--web-intelligence-and-sap-bi
OLAP Universe Change Management
/people/ingo.hilgefort/blog/2008/08/29/businessobjects-and-sap-part-7--olap-universe-change-management
Xcelsius Overview
/people/ingo.hilgefort/blog/2008/09/02/teched-las-vegas--are-you-up-for-the-business-objects-community-xcelsius-challenge
Xcelsius, Crystal Reports and Live Office
/people/ingo.hilgefort/blog/2008/09/03/businessobjects-and-sap-part-9--xcelsius-with-crystal-reports-and-live-office
Xcelsius, Universes and Query as a Web Service
/people/ingo.hilgefort/blog/2008/09/04/businessobjects-and-sap-part-10--xcelsius-with-universe-and-query-as-a-webservice
Install Part #1
/people/ingo.hilgefort/blog/2008/09/17/businessobjects-and-sap--installation-and-configuration-part-1-of-4
Install Part #2
/people/ingo.hilgefort/blog/2008/09/17/businessobjects-and-sap--installation-and-configuration-part-2-of-4
Install Part #3
/people/ingo.hilgefort/blog/2008/09/17/businessobjects-and-sap--installation-and-configuration-part-3-of-4
Install Part #4
/people/ingo.hilgefort/blog/2008/09/17/businessobjects-and-sap--installation-and-configuration-part-4-of-4
SAP Authentication
/people/ingo.hilgefort/blog/2008/09/19/businessobjects-and-sap--configure-sap-authentication
Publishing part 1
/people/ingo.hilgefort/blog/2008/09/23/businessobjects-and-sap--publishing-of-crystal-reports-part-1-of-3
Publishing part 2
/people/ingo.hilgefort/blog/2008/09/24/businessobjects-and-sap--publishing-of-crystal-reports-part-2-of-3
Publishing part 3
/people/ingo.hilgefort/blog/2008/09/24/businessobjects-and-sap--publishing-of-crystal-reports-part-3-of-3
XC, CR and LO Part 1 of 4
/people/ingo.hilgefort/blog/2008/10/03/businessobjects-and-sap-part-1-of-4--creating-a-xcelsius-dashboard-on-top-of-sap-bi
XC, CR and LO Part 2 of 4
/people/ingo.hilgefort/blog/2008/10/07/businessobjects-and-sap-part-2-of-4--creating-a-xcelsius-dashboard-on-top-of-sap-bi
XC, CR and LO Part 3 of 4
/people/ingo.hilgefort/blog/2008/10/07/businessobjects-and-sap-part-3-of-4--creating-a-xcelsius-dashboard-on-top-of-sap-bi
XC, CR and LO Part 4 of 4
/people/ingo.hilgefort/blog/2008/10/10/businessobjects-and-sap-part-4-of-4--creating-a-xcelsius-dashboard-on-top-of-sap-bi
Technical Material
/people/ingo.hilgefort/blog/2008/11/19/businessobjects-integration-with-sap-netweaver-bi--technical-material
SAP Press Book
http://www.sap-press.de/katalog/buecher/titel/gp/titelID-2053?GalileoSession=78576305A3-RD.-s47E
Ingo

RAC database archivelog ?

Hi
in rac enviromenet . 2 node rac setup.each node have own set of redolog .
i have question ? archivelog will generate each node separately or one archivelog for all nodes ?
your reply highly appreciated
regards
kmp

user9372459 wrote:
Hi
in rac enviromenet . 2 node rac setup.each node have own set of redolog .
i have question ? archivelog will generate each node separately or one archivelog for all nodes ?
Archivelogs would be based on the thread of each instance. About their storage, the choice remains with you. If you do want to store them locally, you can but the storage should be visible to the other node also i.e. an NFS based storage. The best is to put them in ASM which does the complete handling by itself.
HTH
Aman....

10.1.2.0.2 WebServices Deployment

Hello,
some genral questions.
Can I deploy Soap Web Services on a OC4J -Instance without anything else as Webcache/Apache and how is the deployment there?
When we deploy WebServices in a WebCache/OC4J-Instance (standalone) is it certified to deploy Oracle PL/SQL WebServices against a 8.1.7.4 Database?
Thank you in advance.
Regards.
Frank

In order for the JPDK to generate links that use resource proxying, both the PPE (Portal) and JPDK must be configured with a shared key.
For the PPE, an init-param called resourceUrlKey must be defined.
For the JPDK, a JNDI environment variable with the same name (resourceUrlKey) must be defined.
The key must have the same value in both places.
Please see section 4.11 of the 10.1.4 Portal Configuration Guide for more information.
The JPDK will fall back to the old behaviour if either key has not been set -- which is what I think you are seeing in your case.
I hope that helps.
Andy.

RMAN and Begin backup mode

Hi guys I have a couple of questiopns...
I want to know whether data is written to datafiles by DBWR when the datafile is in begin backup mode.
What is the difference in archive log creation during normal operation of a database and operation of a database during RMAN backup?

user13087302 wrote:
Normally, Oracle should write only changes into redolog files. But if tablespace is in backup mode, then entire block will be put into redolog as soon as this change it is 1st change occured on that block after enabling backup mode. That is why, we face massive redo log generation if the tablespace is in backup mode. So, logically you should be able to recover to the last SCN you have in hands.What do you mean by last SCN.Is it the SCN before puttting the tablespace in backup mode?Does that mean data present in other files will also be lost even though they are written in datafiles..Pls, look:
SQL> create tablespace myts1 datafile 'C:\app\oracle\oradata\testdb\myts1.dbf' size 10m;
Tablespace created.
SQL> create tablespace myts2 datafile 'C:\app\oracle\oradata\testdb\myts2.dbf' size 10m;
Tablespace created.
SQL> create table myt1 tablespace myts1 as select * from dba_objects where rownum<10001;
Table created.
SQL> create table myt2 tablespace myts2 as select * from dba_objects where rownum<10001;
Table created.
SQL> alter tablespace myts1 begin backup;
Tablespace altered.
SQL> create table myt1_1 tablespace myts1 as select * from dba_objects where rownum<10001;
Table created.
SQL> create table myt2_1 tablespace myts2 as select * from dba_objects where rownum<10001;
Table created.
SQL> create table myt1_3 tablespace myts1 as select * from dba_objects where rownum<10001;
Table created.Backup database:
C:\Documents and Settings\Administrator>rman target /
Recovery Manager: Release 11.2.0.1.0 - Production on Wed Nov 3 15:46:55 2010
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
connected to target database: TESTDB (DBID=2517263760)
RMAN> backup database;
Starting backup at 03-NOV-10
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=44 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00001 name=C:\APP\ORACLE\ORADATA\TESTDB\SYSTEM01.DBF
input datafile file number=00002 name=C:\APP\ORACLE\ORADATA\TESTDB\SYSAUX01.DBF
input datafile file number=00003 name=C:\APP\ORACLE\ORADATA\TESTDB\UNDOTBS01.DBF
input datafile file number=00005 name=C:\APP\ORACLE\ORADATA\TESTDB\EXAMPLE01.DBF
input datafile file number=00006 name=C:\APP\ORACLE\ORADATA\TESTDB\MYTS1.DBF
input datafile file number=00007 name=C:\APP\ORACLE\ORADATA\TESTDB\MYTS2.DBF
input datafile file number=00004 name=C:\APP\ORACLE\ORADATA\TESTDB\USERS01.DBF
channel ORA_DISK_1: starting piece 1 at 03-NOV-10
channel ORA_DISK_1: finished piece 1 at 03-NOV-10
piece handle=C:\APP\ORACLE\FLASH_RECOVERY_AREA\PRIM_DB\BACKUPSET\2010_11_03\O1_MF_NNNDF_TAG20101103T154701_6F2LXQ5C_.BKP tag=TAG20101103T154701 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:35
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
including current control file in backup set
including current SPFILE in backup set
channel ORA_DISK_1: starting piece 1 at 03-NOV-10
channel ORA_DISK_1: finished piece 1 at 03-NOV-10
piece handle=C:\APP\ORACLE\FLASH_RECOVERY_AREA\PRIM_DB\BACKUPSET\2010_11_03\O1_MF_NCSNF_TAG20101103T154701_6F2M0PJ3_.BKP tag=TAG20101103T154701 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 03-NOV-10
Recovery Manager complete.
SQL> select current_scn from v$database;
CURRENT_SCN
    1466019
SQL> drop table myt1_3 purge;
Table dropped.So, we dropped table MYT1_3 and now trying incomplete recovery.
SQL> shutdown abort;
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.
Total System Global Area 431038464 bytes
Fixed Size                  1375088 bytes
Variable Size             322962576 bytes
Database Buffers          100663296 bytes
Redo Buffers                6037504 bytes
Database mounted. C:\Documents and Settings\Administrator>rman target /
Recovery Manager: Release 11.2.0.1.0 - Production on Wed Nov 3 15:51:51 2010
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
connected to target database: TESTDB (DBID=2517263760, not open)
RMAN> run
2> {
3> set until scn 1466019;
4> restore database;
5> recover database;
6> sql 'alter database open resetlogs';
7> }
executing command: SET until clause
Starting restore at 03-NOV-10
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=20 device type=DISK
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to C:\APP\ORACLE\ORADATA\TESTDB\SYS
TEM01.DBF
channel ORA_DISK_1: restoring datafile 00002 to C:\APP\ORACLE\ORADATA\TESTDB\SYSAUX01.DBF
channel ORA_DISK_1: restoring datafile 00003 to C:\APP\ORACLE\ORADATA\TESTDB\UNDOTBS01.DBF
channel ORA_DISK_1: restoring datafile 00004 to C:\APP\ORACLE\ORADATA\TESTDB\USERS01.DBF
channel ORA_DISK_1: restoring datafile 00005 to C:\APP\ORACLE\ORADATA\TESTDB\EXAMPLE01.DBF
channel ORA_DISK_1: restoring datafile 00006 to C:\APP\ORACLE\ORADATA\TESTDB\MYTS1.DBF
channel ORA_DISK_1: restoring datafile 00007 to C:\APP\ORACLE\ORADATA\TESTDB\MYTS2.DBF
channel ORA_DISK_1: reading from backup piece C:\APP\ORACLE\FLASH_RECOVERY_AREA\
PRIM_DB\BACKUPSET\2010_11_03\O1_MF_NNNDF_TAG20101103T154701_6F2LXQ5C_.BKP
channel ORA_DISK_1: piece handle=C:\APP\ORACLE\FLASH_RECOVERY_AREA\PRIM_DB\BACKUPSET\2010_11_03\O1_MF_NNNDF_TAG20101103T154701_6F2LXQ5C_.BKP tag=TAG20101103T154701
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:01:45
Finished restore at 03-NOV-10
Starting recover at 03-NOV-10
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:03
Finished recover at 03-NOV-10
sql statement: alter database open resetlogs
RMAN>Now, check tables:
SQL> select count(*) from myt1;
COUNT(*)
     10000
SQL> select count(*) from myt2;
   COUNT(*)
     10000
SQL> select count(*) from myt1_3;
COUNT(*)
     10000
SQL> select count(*) from myt2_1;
COUNT(*)
     10000So, it does not matter what is the status of any tablespace: in backup mode or not. Incomplete recovery uses archivelogs + redologs.

Linksys wirless network help

I have a genral question sorry if this has been asked before but i have a dell pc and a linksys wirless router and want to get a power book will i be abel to use my rrouter and still get on line with my apple computer

Routers are a rare breed of hardware that is platform independent. Your PB should recognize the wireless network automatically with no intervention from you. Routers are amazing devices!

Logminer does not reveal/show username

Hi Everyone,
Please help out, i have the same issue as below,
Kindly help out on the possible solutions.
I have an issue when using the logminer utility,
Whenever i spool out the results/details of my archivelogs/ redologs.
I only see my username as Seg_owner instead of the username showing
under the oracle user column, it appears blank.
What do i do to resolve this issue as i need it to show that the
logminer can track oracle user loging in to the database?.

As this might be a Toad problem, please run logminer in sqlplus to reproduce the issue.
Please note 10g is a marketing label and doesn't tell anything. You need to post a version number in the form x.x.x.x, or help is not possible.
Also you are kindly requested not to repost this issue every few hours.
Sybrand Bakker
Senior Oracle DBA

Question on recovery of redolog file

hii,
how to open database,
when block corruption error in redolog file.
there are two archive redo log groups.
and database in non archive mode.
thank's in advance

I think this is a very difficult situation. You cannot proceed in opening your database as your redo log is corrupt (current I guess :( ). Your database is no noarchivelog mode, which makes it more diffidcult.
When you say you have two archive log groups, do you mean redo log groups?
Are those groups multiplexed?
In this case you can still recover from this error by dropping the corrupt redo log file and using the valid surviving redo log member.
If you have only two redo log groups, not multiplexed members an no archivelog mode, then I suggest you to dump the contents of your redo log file and detect up to which point you still can find a valid SCN, so can execute an incomplete recover until that scn.
Procedure to dump the contents of your redo log file is:
alter system dump logfile '/xxxx';
This will create a text file with the contents from your redo log file, once you have it you can check up to whic valid SCN you can get. Next perform an incompete recover until that found SCN.
~ Madrid.

Ye olde "delete archivelogs in standby" question

11.2.0.2.0
According to note
Configure RMAN to purge archivelogs after applied on standby [ID 728053.1]
oracle should remove archive logs if we have deletion policy set to "delete applied on standby" which I have set on primary and standby. Monitoring the alert log we see
"Deleted Oracle managed file /path/to/an/archive/log"
so we think cool, its removing them automatically. Question is, when does it delete them? Right now my standby is in sync, yet my alert log is only sporadically showing my logs being deleted which were applied hours ago which I can visibly verify.

Hemant K Chitale wrote:
Oracle automatically deletes archivelogs only when it needs to clear space in the FRA (db_recovery_file_dest).
Hemant K ChitaleI had thought this so tested.
SQL> SELECT
2 substr(name, 1, 30) name,
3 space_limit/(1073741824) AS Quota_GB,
4 space_used/(1073741824) AS Used_GB,
5 space_reclaimable/(1073741824) AS Reclaimable_GB,
6 number_of_files AS files
7 FROM
8 v$recovery_file_dest ;
NAME                             QUOTA_GB    USED_GB RECLAIMABLE_GB      FILES
/u00/oracle/flash_recovery_are        310 19.7361012     18.1420259         46
-- bring the db_recovery_dest_size to 20gb to so we know we're over 90%. according to that first note I posted, the FRA deems anything over 85% as space pressure
SQL> alter system set db_recovery_file_dest_size=20g scope=both;
System altered.
SQL> SELECT
2   substr(name, 1, 30) name,
3   space_limit/(1073741824) AS Quota_GB,
4   space_used/(1073741824) AS Used_GB,
5   space_reclaimable/(1073741824) AS Reclaimable_GB,
6   number_of_files AS files
7   FROM
8   v$recovery_file_dest ;
NAME                             QUOTA_GB    USED_GB RECLAIMABLE_GB      FILES
/u00/oracle/flash_recovery_are         20 19.7437358     18.1420259         47
SQL> So i waited a good ten minutes but still no extra logs cleared out.
So I switched the logs a couple of times in production as well to see would that help and we did get some deleted then to bring the space used down to 17.5.gb which is just below the 85% mark.
SQL> SELECT
2   substr(name, 1, 30) name,
3   space_limit/(1073741824) AS Quota_GB,
4   space_used/(1073741824) AS Used_GB,
5   space_reclaimable/(1073741824) AS Reclaimable_GB,
6   number_of_files AS files
7   FROM
8   v$recovery_file_dest ;
NAME                             QUOTA_GB    USED_GB RECLAIMABLE_GB      FILES
/u00/oracle/flash_recovery_are         20 17.5075302     15.6462598         47
SQL> quick experiment, dropped to 15gb which is below the 17gb currently used. And yes immediately, I can see the files being deleted.
so what I take from this is that if there is any space available in the 15% free then Oracle waits to be woken up by the receipt of a log from primary, sees that theres less than 15% free and deletes logs to below that limit. however, if the space free is less than the space used then oracle wakes up itself and deletes the logs. Cool.
Thanks hemant.
Edited to fix coding

Genral backup questions

Hi People,
I am trying to have better understanding on Backup using RMAN.Appreciate your help on the following questions
1)i only have the rman Controlfile backup(nothing else) and on what scenario i can use it to recover?
2)i only have the rman archivelog backup(nothing else) and on what scenario i can use it to recover?
3)When i am backing up all the tablespace ,do i need to go for Datafile backup also?
4)What Will happen to my backup if the control_file_record_keep_time is set to 3 days and the backup retention policy to 7 days
5)What Will happen to my backup if the control_file_record_keep_time is set to 7 days and the backup retention policy to 3 days.(in this case once my backup becomes obsoete and if i dont have any other recent backup can i use the same backup for restoration)
-Kamesh

>
>
1)i only have the rman Controlfile backup(nothing else) and on what scenario i can use it to recover?If that's all what you have, it won't be of much use. You would need with it, rest of the database files as well as the archive logs also in order to attempt recovery.
2)i only have the rman archivelog backup(nothing else) and on what scenario i can use it to recover?You must know that archivelog are NOT used stand alone. They are actually applied to the database to recovery it. So it would depend on the loss that you have encountered. For example, if you have all the archive logs, and you have lost a datafile without the backup, you can recreate that file and use the archive logs to recover it. If you have lost a control file alone and rest of the things are fine, you can recreate that control file from the script and can still recover.
3)When i am backing up all the tablespace ,do i need to go for Datafile backup also?Let me ask you a question. What you think tablespace contains?
4)What Will happen to my backup if the control_file_record_keep_time is set to 3 days and the backup retention policy to 7 daysControl file has two portions. One is a non-reusable portion and the other is a reusable portion. After the record keep time, the reusable portion would be updated with the new info. The retention policy of the backup would mark it obsolete after the said period.
5)What Will happen to my backup if the control_file_record_keep_time is set to 7 days and the backup retention policy to 3 days.(in this case once my backup becomes obsoete and if i dont have any other recent backup can i use the same backup for restoration)You are done!
HTH
Aman....

ReDoLog & ArchiveLog files

My ReDoLog & ArchiveLog files are growing too fast. they are eating a lot of computer spaces. Can I delete those old files? How?
I'm with 10g, and windowXP

My ReDoLog & ArchiveLog files are growing too fast. they are eating a lot of computer spaces. Can I delete those old files? How? Redo logs must be added by you with some purpose (I guess). You will be a better judge to decide that you need to drop it or not.
You can drop the redo log groups using following command once those are not in use:
ALTER DATABASE DROP LOGFILE GROUP <group number>;
Regards,
S.K.

Redologs on ASM but not archivelogs

Hello,
for the same database, is correct to have redolog on ASM when Archivelogs still on filesystem ?
Thank you.

Hello,
There is no correct answer to this problem. It depends on your strategy. The main advantages of ASM are simplicity and unbuffered I/O so make use of them.
Redo log need both write and read operations aside from archiving (bulk read). On the other side Archived Redo rarely need read operations after its initial bulk write, unless you do frequent recovery. So, you don't want to buffer archived redo logs.
Both can take advantage of ASM feature, so you can put both on ASM.
Later on, if are not satisfy with its performance, you can add more disks to ASM. It is easier to manage than putting archived redo logs on file system and the rest on ASM.
In my opinion it is more important to define strategy of storage tiers within the ASM itself. You can then map each tier to ASM disk group. For example for fast read/normal write you can create tier1 with RAID 1 or RAID 10 and map this tier to ASM disk group. You can then put OLTP/DSS data files into this tier (because they requires fast read). You can create other tiers according to your need based on this example.
clydie.com

Backups check in no archivelog mode -Question

I am trying to figure either DB is backedup or not, I checked its logfiles, it did'n shutdown from last one month, and running in no-archivelog mode.....I can assume its not being backed up from last month , make me right if i am not...........
I have been assigned to apply Oct2007 CPU on this server, & want to take backups first, any suggestions?

if i have export backup, will i be able to do
recovery of db is something goes wrong while cpus
applying with import.........Export are not backups but still popularly used as backups. Yes, if you have the latest export you will be able to get back your database to that point. Make sure you take FULL database export.
I would suggest you to bring down the database and take a cold backup.

Genral question on Archivelog & redolog

Similar Messages

Maybe you are looking for