How to Restore MySQL database from Program files?

In this article, we will discuss about a scenario wherein a database administrator has tape backup of C drive only and production server had compromised by virus attack which was hosted in a third party hosting company. It is very frustrating for every database administrator if they have not schedule MySQL database export to a SQL backup file.

Perform Backup & Restore On MySQL Database Table

Database administrator can use Backup Table syntax for backup and Restore Table syntax for restore MySQL database table. First we will know about how to take a backup of MySQL database table then after how to restore MySQL table from backup created using Backup Table syntax.

Repercussions of InnoDB table corruption and MySQL database recovery

MySQL incorporates a blend of advanced features to offer users a performance-driven and a fully-integrated transaction-safe database. It has excellent capabilities to enable you manage any large database environment. You can use the Query Analyzer to keep a check on query performance and identify the faulty SQL code that is causing a slowdown. Some of its most distinguished features include, crash recovery, roll back, full commit, and row-level locking capabilities. Despite being so much reliable and consistent, this database is prone to corruption. MySQL corruption generally occurs due to improper server shutdown, operating system malfunction, metadata structure damage, etc. As a consequence, all vital database objects become inaccessible. To overcome this problem, you need to go for MySQL database recovery through a proficient third-party utility.

How to Recover Corrupt MySQL Database - MySQL Recovery

MySQL database is an open source database with the best speed and reliability. Most of the branded organizations use it to save their money and time. It offers several syntax to optimize, backup and repair corrupt MySQL database. MySQL database can be corrupt due to several reasons like power failure, malware attack, system failure, hardware failure and many more. Sometimes repair syntax fails to fix the corruption at this situation, you should take help from any third party MySQL database repair software.

In this article, we will discuss a condition wherein a database administrator has tape backup of C drive only and how to recover corrupt MySQL database with the help that tape backup of C drive.

Recover MySQL Database with tape backup: To do this, you will have to follow the below points.

1. Create a new MySQL server environment: Install a same version of MySQL server to restore corrupt MySQL database. For example, if you are at MySQL version 4.1.22, then install the same version.
2. Stop MySQL Service: It is required for adding the data folders.
3. Copy & Paste Database Folder: Copy the database folder from old MySQL database and paste them in new MySQL database folder. Database folder contains information about .frm, .myd and .myi files. The default database folder location is C:\Program Files\MySQL\MySQL Server x.x\Data\database-Folder-Name\.
4. Restart MySQL Service: To restore new MySQL database.
5. Check & Repair MySQL Database Tables: MySQL offers check & repair syntax to check and repair corrupt MySQL database tables as discussed above. Check syntax specifies that there is a corruption in the table and those corrupt tables can be repaired by the Repair syntax. It is very necessary for ensuring that there is no any corruption in the MySQL database tables.
6. Make Backup: If corruption has been fixed by the above mentioned steps then make a backup to avoid data loss in future.

Summary: In the end, if check syntax specifies that corruption in the table and Repair syntax is unable to fix then it is recommended you to try any 3^rd party MySQL database repair software to fix the corruption.

Note: Above mentioned steps will work with MyISAM database storage engine not with the InnoDB database storage engine.

Types & Comparison between MySQL database Storage Engines

MySQL is an open source database and used by the most of the database administrator. It uses database storage engines as a handler to handle different MySQL database tables. There are several storage engines supported by MySQL like MyISAM, InnoDB, Merge, Memory, Archive, CSV, Example, Federated and many more. All of them have their own functionalities and characteristics.

What is the default storage engine? The point comes in your mind. If database administrators do not select the type of storage engine for the database then what is the default storage engine for the database. The answer is InnoDB. It is the default storage engine.

Applied For: After release MySQL 5.5, InnoDB will be the default storage engine.

How to Change Storage engine? A database administrator can change the storage engine for database from the pluggable storage engine. Pluggable storage engine gives users flexibility to select the best fit for their specific case.

InnoDB storage engine is the most used storage engine in comparison of other storage engine. It is used for financial systems, health care applications, telecommunications, retails built on MySQL database. This storage engine is structurally designed to handle transactional related applications that needs crash recovery, high response time, concurrency, and integrity.

Comparison between InnoDB & MyISAM Storage engine: Each storage engine has its own specific characteristic and benefits. Beyond the performance, there are various other factors that suggest for a particular storage engine.

Features	InnoDB	MyISAM
ACID Transactions	Yes	No
B-Tree Indexes	Yes	Yes
Crash Safe	Yes	No
Clustered Index	Yes	No
Storage Limits	64TB	256TB
Foreign Key Support	Yes	No
Full Text Search Indexes	No	Yes
Backup/Point-in-time Recovery	Yes	Yes
Data Cashes	Yes	No
Others

Note: I have tested all above comparison scenarios but there may be many more comparison between these two storage engines.

Summary: InnoDB is default and most used storage engine by MySQL database administrators. It offers efficient ACID transactional capabilities. Now database administrator can create application in the InnoDB storage engine without altering default configuration settings.

About Author: Author is a technical writer and had written several article on MySQL recovery scenarios. You can reach him through comment.

Comments: Share your feedback through comments. I always welcome your comments.

Analyzing the root causes of Index file corruption in MySQL and methods to perform database recovery

MySQL is an open source database that is freely available under GNU General public license. It offers developers a range of storage engines, including Berkeley DB, InnoDB, Heap, and MyISAM. It incorporates adequate security measures and also provides regular security patches to keep the software up-to-date. When it comes to performance, it clearly dominates over the other databases. However, MySQL databases may get corrupt in the event of a virus infection, hardware malfunction, or an unexpected system shutdown. In such circumstances, you lose access to the vital information stored in the database. To overcome this problem, you need to go for MySQL recovery through a reliable third-party utility.

For instance, you might receive the following error message on your screen while trying to access a MySQL table:

“No more room in index file”

Cause: The above error occurs when you try to access a damaged or corrupt MySQL table. This would render all valuable records in the table inaccessible. At this stage, you may use an updated database backup to restore the table. However, if the backup is unavailable, you should follow the below mentioned resolution steps.

Resolution: For resolving the issue, follow the below given steps:

• Firstly, ensure that you have full administrative rights on the database that you are trying to access.
• Use the following commands to verify the integrity of the database table:

CHECK TABLE tablename;

myisamchk *.MYI

mysqlcheck *.MYI

• Use the 'REPAIR' command with appropriate options to repair corruption:

REPAIR TABLE table_name

• Now, use the 'EXIT' command to quit the database. Restart the MySQL server.

If the problem still persists, you should take help of an efficient MySQL repair utility. These software embed a range of advanced and highly robust mechanisms to efficiently scan corrupt MySQL databases and restore valuable objects, such as tables, primary keys, indexes, constraints, etc.

These third-party tools provide preview of all recoverable objects and allow saving log of the recovery process in a separate text file. They support all the latest MySQL versions, including MySQL 3.x, 4.x, 5.x, and 6.x. Furthermore, they are compatible with Windows 7, Vista, Server 2003, XP, and 2000.

How to check & verify InnoDB TableSpace File Corruption

MySQL database offers an offline InnoDB File Checksum Utility (innochecksum) to check the checksums for innodb files. When you run innochecksum utility on the mysql database then it will read and print checksums for innodb tablespace files. After calculating checksum it will compare the calculated checksum with stored checksum, if you found checksum mismatch between calculated checksum and stored checksum that means pages are corrupt.

Process of innochecksum Utility:

Read innoDB tablespace files-->Calculate checksum-->Compare checksum-->Report checksum mismatch

Why developed this tool: There are two main motives to develop this utility that are as:

• To speed up verifying the integrity of tablespace files after power outages.
• To verify the integrity after file copies.

Use as soon as Possible: As we know that checksum mismatch will shutdown the running mysql server so use this utility to as soon as possible rather than waiting production database will encounter the damaged pages.

Note: innochecksum does not work on tablespace files that the server already has open. For those types of files you can use CHECK Table command to check tables within the tablespace.

Recover Tablespace: When innochecksum utility finds checksum mismatch for the innodb tablespace files then it is recommended you to restore the tablespace from backup or start mysql server and use mysqldump to make a backup of table’s within the tablespace.

How to restore without Backup: If you don't have backup of corrupt tablespace then you should try any third party MySQL repair utility that will restore corrupt tablespace of mysql database.

Attention: Always maintain a backup for any database to avoid data loss when disaster will strike to the database.

Summary: innochecksum is an offline innodb file checksum utility that calculates, compares and reports checksum mismatch for innodb database. You can restore corrupt tablespace from backup or using any third party MySQL repair utility.

Incorrect Information in .FRM file of MyISAM storage engine

MySQL database uses tables to store data and all these tables are defined by .FRM file. FRM is an internal file in MySQL database that contains the formating information or structure data for the database. It defines fields and structure of each MySQL's table. Regardless of the storage engine that you choose, every MySQL table is represented by .frm file. File bears the same name as table name with extension .FRM.

Example: suppose you have create a employee table in mysql database then frm file name will be employee.frm that will define the employee table.

Corruption in MySQL database table will resist you to access the table that can be happen due to several reasons like kernel bugs, unexpected power failure, hardware failure, virus attack, and many more. A corrupted table will placed the incorrect information in the frm file and you may got below error message:

“Incorrect information in file: './able-name.frm'”

Resolution: you have three solutions to repair MySQL table after getting above error message:

1. Repair corrupt table by REPAIR TABLE statement
2. Restore from Backup
3. Stop and copy method

Stop and copy method details
Note: if you are using MyISAM storage engine then follow the below steps to repair corrupt table:

• Stop MySQL database
• Take backup of your .frm, .myd, myi files.
• Delete these files from mysql data directory.
• Now start MySQL Database
• Rereate table again by CREATE Table statement.
• Stop MySQL database.
• Copy .myd & .myi files back into the data directory, replace the ones there.
• Start MySQL database again.

If all three methods fail to fix the corruption from table then at last you should try Stellar Phoenix MySQL repair software. MySQL repair software repairs corrupted table created using MyISAM as well as Innodb. This software has around 99 percent success rate. Its very safe and offers easy-to-use interface.

REPAIR TABLE statement to Repair corrupt MySQL Table

MySQL database offers seven syntaxes for proper maintaining of mysql table's records. Those syntaxes are as follows:

1. Repair table syntax 
2. Analyze table syntax
3. Backup table syntax
4. Check  table syntax
5. Checksum  table syntax
6. Optimize  table syntax
7. Restore  table syntax

In this article, we will discuss briefly about first syntax that is Repair Table syntax.

REPAIR Table Syntax: It repairs corrupted mysql database tables. A table gets corrupt due to several reasons like virus attack, system failure, power failure, hardware problem, power failure and so on. Corrupt mysql database tables can be repair by this syntax.

Systax for Repair Table:
“REPAIR [NO_WRITE_TO_BINLOG | LOCAL] TABLE
    tbl_name [, tbl_name] ...
    [QUICK] [EXTENDED] [USE_FRM]”

Above syntax has three options like quick, extended, and use_frm.
When you select “quick” option then repair table syntax will try to repair index file only. This kind of repair is done by myisamchk.

When you select “extended” option then mysql database creates row by row index in place of one row at a time.  This kind of repair is done by myisamchk.

Use_frm option is available only when header file is corrupted or index file missing.  This kind of repair is not done by myisamchk.

Caution: It is the best method to take a backup of corrupt mysql database table before trying “Repair Table” syntax on it.

Sometimes above repair syntax also fails to fix corruption in mysql database at this situation most of the database administrators suggest to try any third party mysql database repair software. It totally depends upon you to choose the best mysql repair tool that meets your requirement and budget.

How to Repair MySQL Table using phpMyAdmin?

MySQL is a relational database and uses table to store the data. Table has column and row to store records. An Individual column must be created to store each type of data like employee name, employee code, employee address, age, sex, and many more. On the other side row contains the actual value that specified with the column of table.

Example: Lets consider an example, we have created an employee details table. Employee details table has five columns employee name, employee code, employee address, employee age, and employee sex. We can insert values into the employee details table through the insert query.

We have inserted John, s0300, New Jersey, 28, and M. Wherein

John= Employee name

s0300=Employee code

New Jersey=Employee adress

28=Employee age

M=Employee Sex.

Corruption in Employee Details Table: Corruption in the above table can happen due to severely reasons like operating system failure, power failure, hardware problem, metadata structure corruption, virus attack, and many more.

How to Repair?: When MySQL database tables get corrupted or damaged, you can repair and restore corrupted MySQL table by carrying out the below mentioned methods.

PhpMyAdmin Method

Third party repair software method

Repair using phpMyAdmin: Follow the below steps to repair corrupt MySQL database table through phpmyadmin.

• Login to the phpmyadmin.
• Select the database.
• Note: if you have only one database then it will be selected by default.
• Goto to the main panel and choose database.
• Select the corrupted MySQL database table.
• Goto to the bottom of the window and click on the drop down menu.
• Select Repair Table from the menu.
• And phpmyadmin automatically fix the corruption in the table.

Third party repair software: If you are unable to repair corrupt MySQL table through above mentioned method then you should try any third party MySQL repair software. MySQL repair software is very helpful in most of the corruption cases and repair table up to ninety nine percent. These software are safe in nature and don't harm your database.

Top three MySQL database repair software: Top three MySQL database repair software are stellar phoenix database recovery for MySQL, recovery for MySQL, recovery toolbox for MySQL.

How to Restore Corrupt MySQL Database Tables

MySQL database is a registered product of sun Microsystems. It is platform independent in nature that means a database administrator can install MySQL database on different operating systems like windows, Linux, and others. MySQL database uses tables for storing the data and records. Sometimes these tables get corrupted by the several reasons like virus attach, software malfunction, improper system shutdown, hardware problem, and so on. When you are trying to repair corrupt mysql database by “mysqlicheck” command but unable to fix then you can try lower level of mysqlicheck command.

You can use lower level of mysqlcheck command in following manner:

Stop Server Process: To use lower level command of mysqlicheck, you should have to stop the server process. You can do it by using service MySQL stop query.

Find Data Files: After end of the server process, you will have to find the data files where tables store. The data files usually present in var/lib/mysql/database_name.

 Now, you can run the given following command against the table.

myisamchk -r -v -f --sort_buffer_size=128M --key_buffer_size=128M /var/lib/mysql/database/table.MYI    

Now, corruption in the mysql table has been fixed

Replace Database: You can replace corrupt database/table with repaired database/table.

Note: In most of the cases, above inbuilt command is able to fix the corruption in tables but sometimes fail to repair. Most of the database administrators recommend to try third party MySQL database recovery software to fix corruption in the MySQL table.

PS: Always try demo version of any software before purchase.

How to Repair Corrupt Table of MySQL Database?

MySQL database has tables to store data. All Big and small organizations use MySQL database for storing the employee's records.  A database administrator can do various operations on table like insert, delete, retrieve, arrange, and many more. Tables are very prone to corruption, there may be various reasons for corruption like Unexpected server shutdown, faulty hardware, virus attach, and more.

Let’s consider a scenario, wherein a database administrator is trying to access MySQL database table and got below error message.

“undef error - DBD::mysql::db selectrow_array failed: Table 'emplyee' is
marked as crashed and should be repaired [for Statement "SELECT LENGTH(thedata)
FROM attach_data WHERE id = ?"] at height/Formula.pm line 344
Height::Attachment::datasize('Bugzilla::Attachment=HASH(0x9df119c)') called ” 

The above error message states that employee's table is corrupt and need to repair.

How to Fix: A database administrator can fix the above error message by the two methods.

1. Repair Table using PHPMyAdmin
2. Repair Table using myisamchk command 

1. Repair Table using PHPMyAdmin: If you have installed PHPMyAdmin on your MySQL server then use this method and follow the following steps:

• Login to PHPMyAdmin
• Choose database that has corrupt table.
• Go to the main panel.
• Go to the list of tables and select the table that you want to repair.
• And finally click on the “Repair Table” button.
• You have done it.

2. Repair Table using myisamchk Command: If you have not installed the PHPMyAdmin on your MySQL server then you can repair corrupt MySQL table via storage engine of MySQL database. Run below script of myisamchk command with r option to repair the corrupt MySQL database table. 

# myisamchk -r profiles.MYI
recovering (with sort) MyISAM-table 'profiles.MYI'
Data records: 80
Fixing index 1
Fixing index 2
Fixing index 3

Last Minute: Sometimes, PHPMyAdmin and myisamchk command are not able to fix badly corrupt MySQL database. At this time, it is recommended you to try any third party MySQL database repair software to fix the corrupt table.

Note: Always try free demo version of any software before complete download.

Discussing MySQL database corruption and an effective resolution for MySQL Recovery

You might have faced circumstances wherein you require transferring your MySQL databases to some other SQL Server. In such situation, it is necessary to create a database dump, which would comprise the structure of database tables and probably a list of SQL statements. This dump can be used for backup purposes in any distressing event of database corruption or inaccessibility. In MySQL, a database is dumped using the 'mysqldump' client. Sometimes you face problems while performing this operation. This unusual behavior is normally caused due to database corruption. As a consequence, you might lose access to your precious database components. To overcome this problem, you need to go for MySQL recovery through a reliable third-party utility.

For instance, when you attempt to dump one of your important MySQL databases, you may receive the following error message on your screen:

“[root@www diaendomet]# mysqldump -ucojjohealth -p --all-databases >

alldatabases.sql

Enter password:

mysqldump: Got error: 29: File '../diaendomet/users.MYD' not found

(Errcode: 2) when using LOCK TABLES”

Cause:

The above error occurred because of corruption in your MySQL database. The database may get corrupt due to reasons, such as virus infections, application errors, operating system bugs etc.

Corruption will make all the database components inaccessible and you may face a critical data loss situation. In this case, a backup will help to restore all the lost or inaccessible data. However, if the backup is missing, follow the below given resolution to recover MySQL database.

Resolution:

• Try the procedure described below to resolve the problem-
• Stop the MySQL server by killing a process named 'mysqld'.
• Switch to the directory '$MYSQL_DATA_DIR'
• Run the 'myisamchk' utility as follows:

myisamchk */*.myi
This will repair all the tables present in the directory.

• Now, start the server and try to dump the database again using the 'mysqldump' utility.

If the problem still persists, you should take help of a MySQL database recovery software. These software are backed by efficient scanning algorithms to perform a complete recovery of the corrupt MySQL database. They can effectively repair and retrieve all the damaged database objects, including tables, relations, keys, constraints, queries etc.

Free download MySQL recovery software from here:
http://www.mysql-database-recovery.com/free-download.php

* Free Download offers free evaluation of the software & preview all the lost files and folder that can be recovered by the software.

The Safe Way to Recover MySQL Database

MySQL is a relational database application, which is widely used for many web based projects. Like any other database application, MySQL also stores various important data. Hence, any problem with the database, results in the complete inaccessibility of the valuable data, which may lead to huge business loss. However, there are many MySQL recovery software that can help you deal with the MySQL problems and recover your precious data back.

MySQL runs as a database server and provides multi-user access to many different databases. For its usability and features, this application is used by many big World Wide Web products, such as Google, Wikipedia, Facebook etc. However, there are occasions, when MySQL gets corrupted and all the data in it becomes completely inaccessible.

There are thousands of such reasons behind possible MySQL corruption. Below listed, are some of the most prominent ones:

1. Unexpected MySQLD (MySQL Server) shutdown
2. Operating system corruption
3. Virus or Malware infection
4. Corruption of files: ".myd", ".frm" and ".myi"
5. Damage to the Metadata structure
6. MySQL bugs
7. Damage to the "ibdata" file
8. Configuration problem etc.

In all the above situations, your MySQL becomes completely inaccessible until it is being repaired by any effective MySQL recovery application.

These software are developed with many fine search algorithms that can scan the whole drive and gather every detail about the inaccessible MySQL database. These powerful utilities are able to repair the database and retrieve the data even in case of severe corruption.

Before running the repairing utility, you need to handle the drive with extreme care. The drive must be guarded against any further corruption or overwriting of the MySQL database in it. Moreover, the software selection is very crucial, as you need to ensure the read-only property of the software, you are using.

However, most of the available MySQL recovery software are completely risk-free in nature and you can run them on your precious database without worrying about the safety of the data in it. Apart from this, these utilities are developed with detailed instructions based graphical user interfaces, which do not require any further assistance in using them.

Stellar Phoenix MySQL Recovery is a wonderful utility to recover MySQL database safely. The software can help you to retrieve your tables, views, relations etc. from both InnoDB as well as MyISAM database engines. This software is developed to work on MySQL 6.x, 5.x, 4.x, 3.x and is compatible with almost all recent Windows operating systems.

Mark willium is an Internet interpreter doing research on the application, that recover corrupted MySQL database and its objects like tables, views, relations and many more.

For More Details about MySQL database recovery software Visit http://www.mysql-database-recovery.com/.

Article Source: http://EzineArticles.com/?expert=Mark_Willium

Article Source: http://EzineArticles.com/6192953

A small analysis on MySQL database corruption and the possible resolution

MySQL is a reliable and higher secure relational database management system that was developed to deal with much bigger databases. Its improved performance, high speed and connectivity make it a better client-server application that has a support for different back-ends, client programs, and Application Programming Interfaces (APIs). But one often faces corruption issues while working with MySQL databases. The corruption may occur due to any reason, such as quitting application in the middle of a write operation, improper system shutdown, hardware issues etc. All these reasons may prevent you from accessing your important databases tables and other objects in the corrupt MySQL database. To recover back all your inaccessible and valuable data in such situations, you need to go for MySQL recovery through a reliable third party utility.

For instance, you may get an error message reading:

"Table './confluencedb/EXTRNLNKS' is marked as crashed and should be repaired"

Causes:

The possible reasons for this error message are-

You may have a limited disk space on the volume where your database is stored
Corruption in some database tables

Any type of corruption in your database may render your database inaccessible. Here, you can use a backup to recover MySQL database and get all your vital data back. You may still try to repair your corrupt database table by following the resolution steps mentioned below.

Resolution:

Follow these steps to repair your MySQL database-
Open up the Control Panel.
In 'MySQL' section, click 'REPAIR' icon against your database's name.

The above steps may help you repair all the corrupt tables in your MySQL database. If the problem still persists, you should take help of an efficient MySQL database recovery tool. These software can easily recover various database objects including tables, views, keys, constraints etc. from your corrupt MySQL database. They support both the MySQL database engines- MyISAM and InnoDB.

Stellar Phoenix MySQL Database Recovery is a comprehensive and highly secure tool that repairs damaged or corrupt MySQL tables created in MySQL 3.x, 4.x, 5.x, and 6.x versions. It enables you to preview all recoverable objects of corrupt MySQL database without even requiring a MySQL installation. It compatible with Windows 7, Vista, Server 2003, XP, and 2000.

Resource: http://www.americanchronicle.com/articles/view/218783

Incorrect Information in .FRM File of InnoDB Table

MySQL organizes all the data as tables, irrespective of storage engine used. If you are using MySQL with InnoDB tables, these tables might get corrupt due to hardware faults, unexpected power failure, MySQL code errors, kernel bugs and other similar reasons. In such cases, InnoDB will typically give some errors indicating table corruption. As a data restoration source, you will need to use your latest database backup. But in case if backup fails to restore required information or doesn’t exist, you should scan your damaged database using third-party MySQL Repair or MySQL Recovery tools.

You might encounter the similar error message while accessing an InnoDB table:

“#1033 - Incorrect information in file: '"table name" .frm”

MySQL crashes after you receive this error message.

Cause: You receive this error message if InnoDB table is corrupted or damaged. An InnoDB table is stored as three files: .FRM (database table definition), .MYI (Index file) and .MYD (table data). This particular error occurs if .FRM table is damaged or corrupted.

Solution:
To solve such problems, you should follow these steps:

Check the table for corruption errors. To do so, you need to use CHECK TABLE command with options like QUICK, EXTENDED, CHANGED etc. that can be used on the basis of check required. The basic syntax is: "CHECK TABLE tablename [options]" If table corruption is the issue, repair it using REPAIR TABLE command. Before using the command, you should make sure that your disk contains about twice as much disk space as of damaged table. REPAIR TABLE command can be used with options like QUICK and EXTENDED with the following syntax: "REPAIR TABLE tablename [options]" If above measures cannot repair the damaged table, check your backup status. If valid backup is available, delete the damaged table and restore from backup. If no valid backup is present, you can make use of MySQL Recovery software. These are advanced tools to analyze and repair damaged MySQL tables. Using powerful scanning, these tools are also capable of maintaining database integrity. Moreover, these MySQL Repair applications come available with rich user interface.

Stellar Phoenix Database Recovery For MySQL is an optimum tool to repair and restore damaged MySQL tables. It supports recovery for both InnoDB (.ibdata, .ibd and .frm) and MyISAM (.myd, .myi and .frm) database storage engines. The software supports MySQL 5.x. This non-destructive MySQL Recovery tool can restore all database objects, like tables, primary key(s), relations and others. It can recover databases of Windows and Linux platforms and is compatible with Windows Vista, XP, 2003, and 2000.

Article is taken from: http://hubpages.com/hub/Incorrect-Information-in-FRM-File-of-InnoDB-Table

MySQL recovery utility for any instance of corruption

In order to start your MySQL server, you used to type the whole path like: "C:\mysql\bin\mysql123" in your DOS prompt. However, sometimes, the MySQL server fails to start with this usual command and the reason may be any possible case of database corruption or damage. In such a case, you cannot be able to access your database and need any MySQL repair utility to repair the troubled MySQL database and recover the data thereof.
In case of any corruption, you may encounter an error message at the start of the MySQL server, which may be as below:

"Default storage engine is not available"

Moreover, in order to resolve the error, if you reinstall the MySQL server without removing the data directory, the server starts normally. However, to your utter dismay, while accessing the any database table, you may encounter another error message on the screen as below:

"ERROR 1146 (42S02): Table 'Tablename' doesn't exist"

Note: Here, the 'Tablename' is the name of the table, you have tried to access.

The above error message appears each time you try to access the table. Even, you cannot be able to resolve the error with the 'mysqlcheck' utility.

In general, the reason behind the occurrence of the error messages is the corruption of the MySQL database, which can have been caused due to an improper system shut down, virus/malware intrusion or any other application malfunction etc.

Resolution:

In order to resolve the problem, you need to repair MySQL with the following command:

Repair Table Tablename
However, with severe corruption, the above command does not able to repair the database and you need to look for any valid backup to restore your seemingly lost MySQL database. If you fail to restore the database from the backup, then, you need to run any MySQL recovery software to recover back the database efficiently.

These read-only utilities are designed with advanced algorithms to repair MySQL database and recover the data safely. Moreover, with highly interactive graphical user interface, you may never find any problem in operating the software.

Stellar Phoenix Database Recovery For MySQL is an extremely powerful utility to repair the corrupt database and recover MySQL database with all its internal structure being intact. The software works well with almost all Windows versions, including Windows Vista, XP, 2003, 2000 and is absolutely easy to use on the parts of experts to normal users.

Advanced Utility to Repair and Restore Corrupt MySQL Table

MySQL database has many commands to systematically maintain its data. All of these commands have different syntax. Out of the several commands, MySQL database has two most common commands that are Optimize and Flush. The Optimize command of MySQL database is used for the defragmenting the database files and use the free space. The Flush command of MySQL database reloads and clears all the internal patches used by database. You can use Flush statement with RELOAD privilege. The above mentioned two commands have different functionalities and features. Using MySQL commands one after the another, your MySQL database table can get corrupted. In such scenarios, your data saved in the table will be inaccessible. For accessibility of table data, you should use an advanced MySQL repair software to fix the problem.

Consider a practical scenario wherein, you run the Optimize command and consequently run the Flush command, after doing this you may got an error message and the data stored in the mysql table become inaccessible.

Root Cause of Problem:

The main cause of the MySQL table corruption is you have used Optimize and Flush command concurrently.

Way to Resolve:

The safe and effective way to repair MySQL table is to run the given below command.

Check corruption limit of mysql table using given statement:
mysqlcheck [options] dbname tablename [tablename2... ]
Repair damaged table using given below statement:
repair table tablename [,tablename1...][options]

The above mentioned steps enable you to repair the mysql database table and fix the problem. But if, these steps fail to fix the corruption issue, that means table is not repair by the command. In such scenarios, you can used the backup of your database for restoring the table. If in case, backup is not updated then only way to repair your corrupt table is by using a third party MySQL Recovery Repair software.

These third party MySQL recovery software used advanced algorithm to repair the corrupted MySQL table. With highly graphical user-documentation, the software is self explanatory and does not require any technical understanding.

Recover Crashed Tables in MySQL Database

MySQL is a popular database management system, a most widely used for web databases, offers efficient techniques to ensure absolute integrity of the database. When you start MySQLD (MySQL Server), it automatically examines all the database tables for integrity. MySQL Server also fixes the tables if they are marked as ´not closed properly´ or ´crashed´. It backs up all the corrupted database tables and makes their entries in the error log. Though, it works in a number of cases, but cannot necessarily fix all the corruption issues and fails to recover MySQL database.

The MySQLD technique cannot repair MySQL database if it is severely damaged. As a practical scenario, where MySQL Server cannot handle the table corruption, you may encounter the below error message-

"Got an error from thread_id=1, mi_dynrec.c:368"

The above error message occurs when you start the MySQL server for accessing the database records that are stored in the MyISAM (MySQL database engine). After initialization, the server examines for integrity of all database tables and attempts to repair the damaged ones. MySQL Server logs this error in error log.

This problem occurs every time you start MySQL Server database, until you repair or remove the damaged tables. All the records that you have saved in MyISAM table become unusable after this error.

Root of the problem:


There are numerous reasons of MySQL database corruption, such as virus infection, unexpected system shutdown, application malfunction, and subsequent editing of the database. MySQL server cannot recognize the database after corruption and thus you face this problem.

Solution:

In order to perform MySQL database recovery in such situations, follow the underwritten steps-

Check the extent of damage to the table using the CHECK TABLE command. Once the corrupt table is identified, use REPAIR TABLE command to repair MySQL database table.

If you have an updated and valid backup of the damaged table, restore it. Backup is the best way to perform MySQL recovery.

In case you do not have a proper backup of your database, you are required to look for alternative MySQL repair solution, which is to use MySQL database recovery software.

MySQL recovery software are particularly designed to repair MySQL database with highly-advanced scanning techniques. They safely repair MySQL database with read-only and non-destructive conduct.

Stellar Phoenix Database Recovery for MySQL is the comprehensive SQL database recovery software that works in all corruption scenarios, with both MyISAM and InnoDB storage engines.