SoFunction
Updated on 2025-03-02

Several common database error types and processing methods in Oracle

1. Database connection error

Database connection errors are usually caused by configuration issues, network issues, or database service not started.

Example: MySQL database connection error

error message:

ERROR 2003 (HY000): Can't connect to MySQL server on 'localhost' (10061)

Solution:

  • Check whether the MySQL service is started.
sudo systemctl status mysql
  • Make sure the binding address in the MySQL configuration file is correct.
# in or in the file[mysqld]
bind-address = 0.0.0.0
  • Check the firewall settings to make sure that connections to the MySQL port (default 3306).
sudo ufw allow 3306

2. Database table locking

Table locking problems usually occur when there are many concurrent transactions and may cause deadlocks or long waits.

Example: MySQL table locking

error message:

ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction

Solution:

  • Find and terminate a session holding a lock.
-- Find a session holding a lock
SHOW PROCESSLIST;
-- Terminate the session
KILL <process_id>;
  • Adjust the lock waiting timeout time.
SET innodb_lock_wait_timeout = 50;

3. Database table corrupt

Table corruption can be caused by hardware failure, disk corruption, or abnormal database shutdown.

Example: MySQL table corrupted

error message:

ERROR 145 (HY000): Table './database/table' is marked as crashed and should be repaired

Solution:

  • useCHECK TABLECommand checklist.
CHECK TABLE ;
  • useREPAIR TABLECommand to repair the table.
REPAIR TABLE ;

4. Insufficient database space

When the database space is insufficient, the insertion or update operation may fail.

Example: Oracle database space insufficient

error message:

ORA-01653: unable to extend table <schema>.<table> by <number> in tablespace <tablespace>

Solution:

  • Increase the data file size of the tablespace.
ALTER DATABASE DATAFILE '/path/to/' RESIZE 100M;
  • Add new data files to the tablespace.
ALTER TABLESPACE <tablespace> ADD DATAFILE '/path/to/' SIZE 100M;

5. Insufficient permissions

Permission issues are usually caused by the user not having the proper permissions to perform certain operations.

Example: MySQL permissions are insufficient

error message:

ERROR 1044 (42000): Access denied for user 'user'@'host' to database 'database'

Solution:

  • Grant appropriate permissions to the user.
GRANT ALL PRIVILEGES ON database.* TO 'user'@'host';
FLUSH PRIVILEGES;

6. SQL syntax error

SQL syntax errors are caused by the fact that SQL statements do not comply with the syntax rules of the database system.

Example: PostgreSQL SQL syntax error

error message:

ERROR:  syntax error at or near "FROM"
LINE 1: SELECT * FORM table;
                    ^

Solution:

  • Check and fix syntax errors in SQL statements.
-- WrongSQLStatement
SELECT * FORM table;
-- CorrectSQLStatement
SELECT * FROM table;

Summarize

To handle database errors, you need to conduct detailed analysis of specific error information and take corresponding measures to solve the problem. Understanding and mastering common database errors can help database administrators quickly locate and solve problems and ensure the stable operation of the database system. Each database system (such as MySQL, Oracle, PostgreSQL, etc.) has its specific error codes and handling methods. It is recommended to refer to the official documentation for more accurate and detailed solutions.

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