Tips To Solve 'ora-1578' Error'

Data in an Oracle database is stored in logical units called blocks (also called, logical blocks or data blocks). This is the finest level of database allocation in Oracle. However, if it gets corrupted, it can cause serious data loss. The common reason of block corruption are, operating system issues, Oracle problems, defective I/O hardware, and recovery attempts from 'NOLOGGING' or 'UNRECOVERABLE' database actions. A corrupted Oracle database is generally not accessible by the user and thus necessitates you to either restore it from backup or Repair Oracle Database.

To exemplify such problems of data blocks corruption, consider the following issue. Suppose you are an Oracle administrator and have an important database that contains relevant information. But, suddenly when you try to access this database, you encounter the below mentioned error message:

ORA-1578

The error doesn't show any additional information about the cause and behavior of database issue.

Cause:

'ORA-1578' occurs when the data blocks of Oracle database are marked as corrupt. In this specific case, it has occurred because the NOLOGGING' or 'UNRECOVERABLE' database operation has been performed on its object(s) and the file containing this data has been subsequently recovered. This sequence of events ultimately results in corruption of blocks that have been affected by these operations.

Solution:

• You should follow the below sequence of steps to recover from such problems:
• You need to first determine the objects that have been affected due to corruption

If the database exists in ARCHIVELOG mode, a good backup of affected data files is available, and all the ARCHIVELOGS until the current time are available (from the time of first backup), you should go for a complete database recovery. However, if only the temporary tablespace is affected, no user action is required.

Alternatively, you can use COLD backup or an existing export file to restore the database.
If none of the above solutions works for you, it is suggested to use a third-party utility to oracle database recovery. These are exclusive Oracle database repair tools designed to Repair Oracle Database and restore its data to a secure location without changing its contents.

Oracle Recovery software is a high-end tool that repairs corrupted Oracle database and restores all database objects like, tables, views, cluster tables, and more to a secure location. The oracle database repair software employs risk-free scanning algorithms to Recover Oracle Database. Supporting Oracle 9i, this utility has a user-friendly interface for easy working.

Tips To Resolve table Doesn't Have A Correct Definition Error Message

MySQL database tables can be corrupted due to three main reasons improper system shutdown, application malfunction, and virus attack. Corruption in tables primarily results into an error message that does not allow you to view the table records. In most cases, the error message displays the cause for corruption, helping you to identify and resolve the exact problem. However, if you are unable to understand the error message or do not want to experiment with your database, then an easy way to access your table data is to restore it from an updated backup. While a valid backup allows you to surmount any corruption scenario, corruption or damage in backup file leaves you with no option, but to use an advance third-party mysql repair application.

As a practical instance, you receive the below error message when you attempt to access the records stored in the Accounts table:

\mysql\bin\myisamchk: error: 'Accounts' doesn't have a correct index definition . You need to recreate it before you can do a repair

The above error message makes the data stored in Accounts table inaccessible. Additionally, the same error message pops up each time you attempt to access Accounts table.

Cause:

The fundamental reason responsible for the occurrence of the above error message is Accounts table corruption due to improper system shutdown.

Resolution:

For absolute resolution of the above error message and to access Accounts table table data, you will either need to recreate or repair the table (as suggested in the error message). To recreate the table you will need to create a new table and import all the data from a valid backup. For repairing the table, run the below command:

Repair Table Accounts

While the above resolutions allow you to access the data in most situations, the possibilities of these resolutions falling short always exist. In such situations, you will need to opt for advance repair mysql database software to repair the corrupted database. Such tools provide absolute MySQL Repair by employing advanced scanning and repairing algorithms.

Database Recovery For MySQL comprehensively repairs corrupted MySQL databases created in MyISAM and InnoDB mysql database repair storage engines. Designed for Windows Vista, XP, 2003 and 2000, the MySQL Repair software recovers and restores MySQL database components (tables, primary key(s), and relations, etc.) on default or new user-specified location.

What are the Common Causes of DBF File Corruption in Visual FoxPro?

Visual FoxPro is a popular data-centric procedural and object-oriented programing language and RDBMS (Relational Database Management System), developed by Microsoft Corporation. The application stores your significant data in DBF (Database File) file. You can retrieve data from DBF file using queries. Under some circumstances, the DBF file gets damaged and you cannot access data from it. It causes serious data loss situations and requires DBF Recovery to be resolved.

There are numerous reasons, which can result into Visual FoxPro database file corruption. Some of the common reasons of data corruption issues in Visual FoxPro are as given below:

• Improper termination of Visual FoxPro while manipulating the data- This problem can occur due to internal application inconsistency errors, fatal exception errors, page faults, power surges, system crash, and voltage spikes.

• Virus Infection- Viruses are one of the biggest threat to your data. You should regularly scan your system using an updated Anti-virus application.

• Data storage components- You should regularly check your hard drive for fragmentation and errors.

• Conflicting applications- Third-party software like screen savers and Anti-virus may cause several conflicts with the Visual FoxPro, which can lead to DBF corruption.

• Faulty or substandard network components- Since Visual FoxPro application handles data too quickly, it could stress your network. Such components might include network interface cards, hubs, switches, network drivers, and cables.

• File locking problems- If one DBF file user performs any operation, which locks the memo file of table, and second DBF user tries to open same database table and then access memo field, second user might open memo file with wrong blocksize. It results into the memo file corruption.

• Service packs and network settings- You should make sure that the database servers are using the latest service packs. Also check the settings, such as disk caching, on client computer. You can also try switching the drivers of network clients.

If you run across any of the above situations, the DBF file becomes completely unusable. If corruption is severe, you can not even open the Visual FoxPro application. In such cases, DBF file repair tools are required to extract inaccessible data.

DBF Repair software use highly-advanced scanning mechanisms to ensure absolute recovery in all DBF file corruptions situations. They repair DBF file in a safe, quick, and easy way.

DBF Recovery is a powerful and advanced utility to successfully repair and restore damaged DBF file. The software works well with Visual FoxPro 6.0-9.0 and dBase III-V. It restores all DBF file items, including indexes, table names, column names, primary keys, and column data types.

Resolving Error 8906 in MS SQL

In MS SQL Server database, a PFS (Page Free Space) page has one byte for each of the pages existing in the file interval it maps. This byte contains a bit that indicates that the associated page is a mixed page. An IAM page includes a mixed page array, which is an array of eight page IDs, to keep the mixed pages that have been allocated to the index. In some cases, when the database goes corrupted, the page containing 'mixed page' bit is not recognized correctly. Thus, you can detect such specific cases of database corruption and, take corrective measures for MS SQL Repair.

Most of the SQL database corruption problems can be analyzed and detected by running DBCC CHECKDB command. Let's consider the below error message, which typically appears when the discussed problem occurs. When you run DBCC CHECKDB command to check the integrity of database, following error might pop up:

Server: Msg 8906, Level 16, State 1, Line 0
Page P_ID in database ID DB_ID is allocated in the SGAM SGAM_P_ID and PFS PFS_P_ID, but was not allocated in any IAM. PFS flags 'PFS_FLAGS'.

Cause:

Error 8906 is most likely to occur when a page with 'mixed page' bit set up in PFS byte has not been detected as an IAM page or in a mixed page array of an IAM page, which indicates database corruption.

Solution:

If you encounter error 8906 after running DBCC CHECKDB on your SQL Server database, apply the below measures to solve it:

Run hardware diagnostics to isolate hardware-related problems. Corrupted hardware components are known to cause these issues if database corruption persists.

Restore the database from last good backup available.

If no clean backup is available, run DBCC CHECKDB without any repair clause to know the extent of damage and required SQL Repair clause. Again run DBCC CHECKDB command with the recommended repair clause. Make sure to backup your database before executing the repair command, in order to avoid post-crash results.

Use a third-party MS SQL Repair utility, in case DBCC CHECKDB doesn't work.

For best results, it is recommended to use SQL Recovery software. Designed to run powerful and safe scanning algorithms, this SQL Repair utility can restore all database objects in a simple way. The application supports MS SQL Server 2008, 2005, and 2000.

Mysql Database Corruption Due To Virus

Computer Virus are the programs that are primarily designed to provide harm to the files stored in your computer system. In most cases, these viruses get installed in your system through Internet and replicate themselves by copying them on the other programs. These viruses can also corrupt your MySQL database and make them unmountable. In such situations, the records stored in your database components becomes inaccessible. To overcome such corruption scenarios, an easy way is to restore the data from an updated backup. However, if you have not created database backup or backup falls short to restore the required data, then you will need to opt for advanced MYSQL DATABASE REPAIR application.

Consider a practical scenario, where your table index becomes corrupt after a fatal virus attack. This further makes the database records inaccessible. To prevent virus attack on your system, you will need to follow the below steps:

• Always have an anti-virus software installed in your system.
• Always perform a thorough scan of your external media before connecting it to your computer system.

To repair your corrupted database after the a fatal virus attack, you will need to follow the below steps:

• Run the Check command to examine the level of corruption.
• Run the Repair command to repair the corrupted database tables.

The above commands enable you to repair your database after all virus attacks. However, if the commands fail to resolve your problem, then you will need to restore the database components from an updated backup. But there have been many case studies where the users have not created any backup or their database backup has been corrupted, damaged, or inaccessible. In such situations, you will need to opt for advanced Database Recovery Software.

Such tools use powerful repairing methods to provide absolute MySQL Repair in all situations. With interactive user-interface, these tools are easy-to-understand without any prior technical knowledge. These read only software provide risk free repair of database without modifying any data in the original MySQL database.

Database Recovery For MySQL is a proficient MySQL Database Repair software to repair damaged databases built in MyISAM and InnoDB MySQL database storage engines. The repair tool recovers and restores MySQL database components (tables, primary key(s), and relations, etc.) on a new user-specified location. It is designed for Windows Vista, XP, 2003 and 2000 operating systems.

High Availability Disaster Recovery Feature In Ibm Db2

IBM DB2 is a relational model database server or relational database management system, developed and marketed by IBM. It provides greater data availability and stability, as compared to other database management systems. You can prevent DB2 database corruption and need of DB2 Database Recovery using DB2 HADR (High Availability Disaster Recovery) feature. DB2 HADR is a data replication characteristics, which offers high availability for both complete and partial site failures. This features protects against the data loss by duplicating data changes from source database, known as primary, to target database.

A complete DB2 site failure may take place when any natural disaster, like fire or flood, causes the whole site to be destroyed. Since the HADR deploys TCP/IP to communicate between standby and primary databases, DB2 database may be situated at different locations. When any disaster takes place at primary site, the database availability is maintained through standby database. After the standby database takeovers primary database, the original database can be brought back to working state and return the database to primary database's status. It is called failback.

The partial DB2 site failure may take place when an application malfunction, operating system failure, hardware problems, and network issues damage your DB2 database. Without HADR, DBMS server or machine where DB2 database is stored, needs to be restarted. The time it requires to reboot the server and database is unpredictable.

In case the database corruption is serious and it is taking long time to process, critical situations of database unavailability may occur. It is highly recommended to have a complete HADR plan to ensure absolute safety of your mission-critical data on DB2 database server.

In case you do not have HADR configured or it fails to bring your database back to working state, an absolute backup of the database is required. You can restore damaged database very quickly and easily from the backup and prevent data loss. However, if the backup is either not updated or not available, DB2 Recovery becomes need of hour. You can effectively and quickly recover DB2 Database using powerful and advanced third-party DB2 database repair applications.

The DB2 database recovery software are capable of systematically scanning whole DB2 database and extracting all inaccessible data from it. With interactive user interface and simple graphical user interface, they do not require sound technical skills to retrieve data from damaged database.

DB2 Recovery software repairs damaged DB2 database and restores it back to original and working state. The software works well with IBM DB2 (UDB) v8. It restores all DB2 database objects, such as tables, views, schemas, triggers, buffer pools, and containers.

How to Repair and Restore Corrupt DBF File of Visual FoxPro?

Visual FoxPro is a procedural and data-centric object oriented database programing language, developed and marketed by Microsoft Corporation. Visual FoxPro is closely integrated with the relational database engine that extends xBase capabilities of FoxPro to support Structured Query Language (SQL) data manipulation and query. It is a dynamic programing language, which doesn't need any additional programing environment. The FoxPro stores your data in the form of tables, which are stored in DBF file format. In some cases, the DBF file may get damaged and become inaccessible. This behavior leads to severe data loss and requires DBF Recovery solutions to be fixed.

The table file of Visual FoxPro (DBF file) contains two records- the header record and the data record. Header record of DBF file defines complete structure of FoxPro table and stores additional information about the table. Header record begins from the file position zero. The data record follows the table header, in successive bytes, and stores actual data of table's fields.

• Data in FoxPro data file begins from the position pointed in the bytes 8 to 9 of header record. The data record start with one delete flag byte. In case the delete flag byte is 0x20 (ASCII space), record is not removed. If bye it 0x2A (ASCII asterisk), record is removed.

Length of the data record is considered by adding all the defined lengths of table fields. Integers in FoxPro table are stored with least important byte first mechanism.

Under some situations, the DBF file or Visual FoxPro table gets damaged and puts you in need of DBF Database Repair solutions. The most common causes of DBF file corruption are as given below:

• File header or header record corruption.

• Application malfunction of Visual FoxPro.

• Virus infection.

• Improper system shutdown due to power outage or system crash.

If you come across any of the above situations, you need to recover DBF file by restoring it from the most recent and valid backup. To ensure highest data safety, you must regularly update your backup.

However, in case you do not have a valid backup, you need to repair DBF file using advanced and powerful commercial applications. The software are particularly designed to methodically scan whole DBF file and extract all inaccessible data from it. They have highly-interactive user interface to offer easy recovery.

DBF Recovery is the most excellent solutions to successfully tackle all DBF file corruption scenarios. The software works well with Visual FoxPro 6.0 to 9.0, dBase III, dBase IV, and dBase V. It retrieves all DBF file objects, such as indexes, table name, column data type, primary keys, and column name.

Oracle Data Block Corrupted Post System Malfunctioning

Each Database Administrator (DBA) has his own story of Oracle database corruption. While Oracle database corruption is rare, but when ever they happen, the DBAs surely have sleepless nights. It becomes easy for the DBAs to overcome database corruption, if they have created a valid backup of their database. But, in case the DBAs have forgotten to create a backup or backup file itself is corrupted, then these DBA's need to search for an effective third-party Oracle Database Recovery application that can repair their database.

While the reasons for Oracle database corruption are many, one of the most common is corruption of Oracle data block. These blocks are one of the main Oracle database elements that consists of various operating system blocks. The size of Oracle data block is assigned by a DBA at the time of creation of database. Each data block consists of a block directory, block header, free space, and ITL (transaction list).

Each Oracle data block needs to surpass the below communication points for physical storage:
Disk controller cache
Storage Area Network cache
Oracle SGA and sessions' PGA
UNIX buffer cache
Physical disk spindle

This block can be corrupted while transportation due to below reasons:
Damaged Input/Output hardware
Incompatible device driver
Memory issues
Paging problems

After the Oracle data block is corrupted, the data block becomes unreadable, further resulting into inaccessibility of Oracle database records. In such cases, it is advisable to restore the data from an updated database backup. But, if the data backup is deleted, corrupted, or damaged, then it becomes imperative for the DBA to repair database using an advanced oracle database recovery software.

An Oracle Database Repair tool employs high-end scanning procedures to Recover Oracle Database and restore the recovered database at user-specified location. The database recovery utility is designed with an easy to understand user-interface, that helps the user perform recovery easily. Such tools are non-destructive and do not make any change to the original database file.

Oracle Recovery is capable of recovering almost all database components, such as, tables, synonyms, roles, cluster tables, schemas, views, table spaces, indexes, and sequences. Supported by Oracle 9i, the recovery tool can Recover Oracle Database after almost all instances of database corruption. It supports Windows XP and 2003 operating systems.

Resolving data Files Are Corrupt Error Message

There are numerous instances when attempt to resolve one error message and result in complete corruption of your MySQL database. So, it always advisable not to troubleshoot an error message for which you have no knowledge. However, if you are already in such a situation, then a safe way to access your database records is by restoring them from an updated database backup. But, if in case, you have not created any backup or the backup file itself has been corrupted, then you will need to opt for advanced third-party Mysql Database Repair software.

To illustrate the above case, consider a scenario where you receive the below error message when you try to access your database records:

Cannot connect to localhost (100061)

On trying to resolve the above error message, you make some changes in the database structure, which further results in the corruption of your database. You can determine MySQL database corruption by viewing the logs of your database:

InnoDB: Database physically writes the file full: wait...
InnoDB: Cannot initialize created log files because
InnoDB: data files are corrupt, or new data files were
InnoDB: created when the database was started previous
InnoDB: time but the database was not shut down
InnoDB: normally after that.
090329 22:43:00 [ERROR] Default storage engine (InnoDB) is not available
090329 22:43:00 [ERROR] Aborting

Your database records become inaccessible after the above error message appears.

Resolution

To systematically repair your database and access its records, you will need to follow the below steps:

1.Check the level of database corruption using the below command:

mysqlcheck [options] dbname tablename [tablename2... ].

2.Use the below command to repair your database:

repair table tablename [,tablename1...][options]

While the repair command comprehensively repairs corrupted databases in most situations, the prospects of database corruption still exist. In such situations, the records stored in the database can be accessed by using powerful third-party Mysql Database Recovery software. Such repair applications are built by rich experienced data recovery experts and use advanced repairing mechanisms to repair your database. These MySQL Repair utilities are easy to understand and provide risk-free database repair.

Database Recovery For MySQL repairs and restores recovered databases built in MyISAM and InnoDB MySQL database storage engines on default or user-specified location. The MySQL Repair software supports Windows Vista, XP, 2003 and 2000 operating systems, and recovers lost tables, primary key(s), and relations, and similar database components.