Thursday, May 27, 2010

Rectifying Error Message “Unsupported extension used for table” in MySQL database

To take the advantages of the new privileges added in the new version of MySQL database, most of us upgrade our MySQL tables to new version. The utility available for upgradation of MySQL tables is known as mysql_upgrade. While upgradation has various advantages, it can also result in complete or partial loss of data from the tables. In such situations, backup enables you to restore the lost data. But, if there is no backup available or it fails to restore the required data, then you need to repair the corrupted table(s). To do so, you need to use advanced MySQL Database Repair applications.

Consider a practical scenario, where you upgraded your MySQL database from rev 4.0.13 to rev 4.0.14. After the upgradation is complete, you discover that some of your important tables are corrupted. In addition, when you attempt to open those tables, you encounter the below error message:

“e-systemusr/local/mysql/bin# ./myisamchk -a
/usr/local/mysql/var/centralf/postscobe1.MYI

myisamchk: error: 138 when opening MyISAM-table
'/usr/local/mysql/var/centralf/postscobe1.MYI'

e-systemusr/local/mysql/bin#.......”

The data saved in the MySQL tables becomes inaccessible after the occurrence of the above error message.

Cause:

The main cause behind corruption of MySQL tables is improper or interrupted upgradation of MySQL database.

Resolution:

To repair the corrupted MySQL tables and access their data, you will need to follow these steps:

· Use the below command to check and analyze the corruption in MySQL table:

Check Table tablename

· Next, run the below command to repair MySQL table:

Repair Table tablename

· You can also run the following command:

REPAIR TABLE TABLENAME USE_FRM

Though, it won’t be useful here, as it will show the tables as empty.

However, if all the above measures fall short of repairing the corrupted tables, then you will need to use advanced MySQL Repair tools. Such MySQL Database Repair utilities incorporate high end scanning methods to completely repair and restore the data stored in MySQL tables. With self-descriptive and largely graphical user interface, such repair utilities serve as user-friendly solutions that do not require any sound technical skills.

Wednesday, May 19, 2010

External Program Corrupts MyISAM Table

There can be numerous factors responsible for the corruption of MyISAM table. Few of the most common are simultaneous modification of table by two different applications (like an external program and by the server), killing of MySQLD process in the middle of a write operation, improper system shutdown, MySQL bugs, and virus attacks. A common symptom of a MyISAM table corruption is the occurrence of the error message when the user attempts to access the records saved in the table. In such cases, the records saved in the MyISAM table become inaccessible. For easy accessibility of table records in such cases, the database user needs to restore the table from an updated backup. But, if the backup is created on a storage media that is not accessible, then the user is not left with any option, but to repair the corrupted table. To effectively do so, the user needs to use an advanced MySQL Database Repair application.

As a practical case, you use myisamchk (external program) to change the records saved in the Employee (MyISAM) table. However, that same table was also being modified by the server, at the same time. However, when the myisamchk completes its task, and you attempt to view the records saved in the Employee table, you encounter the below error message:

“Incorrect key file for table: '...'. Try to repair it”

After the above error message appears, all the records of Employee table become inaccessible. Moreover, no rows are displayed in the Employee table when you run a query.

Cause:

The main cause for the corruption of the Employee table is simultaneous modification of table by both myisamchk and server.

Resolution:

To resolve MyISAM table corruption and to access the table data, you need to follow the below steps:
  • Use 'CHECK TABLE' command to check the health of the Employee table.
  • Use 'REPAIR TABLE' command to repair the Employee table.
While the above steps can repair Employee table in most cases, the possibility of these measures failing to repair the database table still persists. In such situations, you need to search for an effective MySQL Repair application. A MySQL Recovery tool uses powerful scanning methods to repair MyISAM table, irrespective of the degree of its damage.

Resource Link: http://www.progtalk.com/viewarticle.aspx?articleid=1929

Monday, May 10, 2010

MySQLD Read/Write Process Interrupted

MySQL Server (MySQLD) is an important program that performs almost all operations during a MySQL installation. The server is also responsible for managing and accessing records that are saved in MySQL data directory. This directory contains all the necessary information, such as, databases, tables, log files, and status files that are required by the user. Interruption in MySQLD process while it is performing some read or write operation on any MyISAM table results into corruption of that table. In such cases, the user encounters an error message while accessing the corrupted table, further resulting in inaccessibility of data saved in that table. To surmount such table corruption error messages, you need to restore data from an updated backup. However, if no backup of the table is available, then the user needs to repair the table using advanced MySQL Repair utility.

Consider a practical scenario, where you run an update command on a MyISAM table. While the MySQLD was performing the updates, it crashed in between due to power outage. However, next time you try to open that table, you encounter below error message:

“Incorrect key file for table: '...'. Try to repair it”

The error message means that the MyISAM table is corrupt. The message repeatedly occurs each time you try to access the database.

Cause:

The main cause of corruption is killing of MySQLD process while performing a write operation.

Resolution:

To resolve MyISAM table corruption and to access the data saved in it, you need to:

Run 'CHECK TABLE' command to verify the health of MyISAM table.
Next, run 'REPAIR TABLE' command to repair the corrupt MyISAM table.

While the above steps successfully repair most corrupted MyISAM tables, there are still some situations where these steps fail to repair. For such scenarios, you need to opt for an effective third-party MySQL Repair application. A Repair MySQL Database utility provides complete MyISAM table repair using advanced repair algorithms.

MySQL successfully repairs logically corrupted MyISAM table in only three steps. The MySQL Database Repair utility also repairs InnoDB tables. The utility provides risk-free repair as it does not makes any change in the tables. Supported by MySQL 5.x and 4.x, the tool can be installed on Windows 7, Vista, XP, 2003 and 2000 operating systems.

MySQLD Read/Write Process Interrupted

MySQL Server (MySQLD) is an important program that performs almost all operations during a MySQL installation. The server is also responsible for managing and accessing records that are saved in MySQL data directory. This directory contains all the necessary information, such as, databases, tables, log files, and status files that are required by the user. Interruption in MySQLD process while it is performing some read or write operation on any MyISAM table results into corruption of that table. In such cases, the user encounters an error message while accessing the corrupted table, further resulting in inaccessibility of data saved in that table. To surmount such table corruption error messages, you need to restore data from an updated backup. However, if no backup of the table is available, then the user needs to repair the table using advanced MySQL Repair utility.

Consider a practical scenario, where you run an update command on a MyISAM table. While the MySQLD was performing the updates, it crashed in between due to power outage. However, next time you try to open that table, you encounter below error message:

“Incorrect key file for table: '...'. Try to repair it”

The error message means that the MyISAM table is corrupt. The message repeatedly occurs each time you try to access the database.

Cause:

The main cause of corruption is killing of MySQLD process while performing a write operation.

Resolution:

To resolve MyISAM table corruption and to access the data saved in it, you need to:

Run 'CHECK TABLE' command to verify the health of MyISAM table.
Next, run 'REPAIR TABLE' command to repair the corrupt MyISAM table.

While the above steps successfully repair most corrupted MyISAM tables, there are still some situations where these steps fail to repair. For such scenarios, you need to opt for an effective third-party MySQL Repair application. A Repair MySQL Database utility provides complete MyISAM table repair using advanced repair algorithms.

MySQL successfully repairs logically corrupted MyISAM table in only three steps. The MySQL Database Repair utility also repairs InnoDB tables. The utility provides risk-free repair as it does not makes any change in the tables. Supported by MySQL 5.x and 4.x, the tool can be installed on Windows 7, Vista, XP, 2003 and 2000 operating systems.

Monday, May 3, 2010

Resolving MySQL Error- “Page Directory corruption: supremum not pointed to”

MySQL is a widely used RDBMS (Relations Database Management System), which uses two different storage engines- InnoDB and MyISAM. InnoDB is included as a standard storage engine in all modern binaries, which are distributed by MySQL AB. It has ACID (Atomicity, Consistency, Isolation, Durability) compliant-transaction support, along with the foreign key support. However in some situations, you may encounter errors while starting the InnoDB database that indicate database corruption. Corruption renders your database tables inaccessible and cause serious data loss situations. In order to retrieve the damaged database tables you need to restore them from an updated backup. But, if the backup is unavailable, go for MySQL Repair solutions.

In a practical scenario, you may encounter startup failure of the InnoDB storage engine with “Signal 11”, prefaced by an unexpected shutdown of the InnoDB. At the same time, you may also come across the below error message:

“Page directory corruption: supremum not pointed to.”

The server startup variants can not complete successfully. After startup failure, you see the log entries in .err file of MySQL application, similar to the following one:

“InnoDB: Error: all log files must be created at the same time.
InnoDB: All log files must be created also in database creation.
InnoDB: If you want bigger or smaller log files, shut down the
InnoDB: database and make sure there were no errors in shutdown.
InnoDB: Then delete the existing log files. Edit the .cnf file
InnoDB: and start the database again.
060218 16:45:01 [ERROR] Default storage engine (InnoDB) is not available
060218 16:45:01 [ERROR] Aborting”

Cause

This issue is caused by the corruption of page directory of InnoDB storage engine. The same problem may also occur if the storage engine or database are corrupted.

This overall behavior of MySQL application indicates database corruption and needs MySQL Repair.

Resolution

You can sort out this problem by replacing the MySQL Server dir with the most recent backup. In case the backup is not updated or is not available in place, situations can be quite difficult to handle manually.

In such circumstances, one has to Repair MySQL Database using third party applications. They are particularly designed to methodically scan the database tables and repair, and restore them. You can Recover MySQL database on your own using these self-descriptive applications having interactive user interface.

MySQL is an advanced software that successfully restores damaged database in all corruption scenarios. It works well with MySQL 5.x and 4.x. The software supports both InnoDB and MyISAM storage engines and restores all database objects.