Oracle Common Error Diagnosis _oracle

The Oracle tutorial you are looking at is: Oracle Common error diagnosis. This type of error in Oracle is described in detail in the Oralce documentation, but the reasons and measures are not detailed, and this article focuses on how to resolve such errors.

　　1, ORA-12571, ORA-03113, ORA-03114, ORA-01041

Features: Client (proxy or application server) there are times such disconnected errors

Cause: If once in a while, it may be a network reason or a user abort, and if it does, it will be inconsistent with the client's character set.

Action: If it happens occasionally, add a row to the server-side protocol profile Protocol.ora

Tcp. Nodelay=yes;

If this occurs frequently, the client is inconsistent with the service-side character set or the network reason.

The client's character set is defined in the registry: Hkey__local__machine/software/oracle/nls__lang

Set the tcpmaxdataretransmitions=20 in the TCP parameter entry in the client registry.

　　2, ORA-01000

Feature: The maximum number of cursors allowed by the session is reached

Reason: The maximum number of cursors allowed by the session is reached

Measures: There are two ways to solve this problem:

(1) Initialization of the file init . Ora file to increase the number of open_cursors, general requirements greater than 200.

(2) At the application level, related to development tools, such as setting up maxopen_cursors.

　　3, ORA-01545

Feature: A rollback segment is not available

Reason: (1) when the rollback segment online, but the rollback segment is not available, such as the rollback segment of the table space offline;

(2) when the rollback segment online, but the rollback segment has online, such as the rollback segment was used two times, typical cases such as OPS, rollback segment can not be public;

(3) When the rollback segment is deleted, there are active transactions in the rollback section;

Measures: (1) to ensure that the rollback segment can be

(2) From initialization of the file init . Ora parameter rollback) segments to delete the specified rollback segment.

(3) The rollback segment can be deleted from the table space, cancel the undo transaction

　　4, ora-0165x

Feature: Table space does not have enough space for distribution

Reason: The table space is full; the storage parameter is unreasonable, next is too small; there is no contiguous interval

Action: If the table space is full, add the file for the tablespace, or add initial and next if the storage parameter is unreasonable, and if there is no contiguous interval, you need to merge the free tablespace.

View space debris with Dba_free_space

　　5, ORA-01555

Feature: Current session cannot read previous version of data

Reasons: There are many reasons, the main reasons are as follows: The rollback segment is too small, too little; rollback segment conflict; Cross Submit (Fetch_across)

Measures: Increase the number of rollback segment;

　　6, ORA-04031

Feature: Shared pool memory area not enough memory, or generated memory fragmentation

Reason: The shared pool does not have contiguous memory space when trying to load a large packet or executing a larger stored procedure.

Measures: If the memory is not enough, then increase share) pool_size;

In the case of memory fragmentation, execute ALTER system flush Share_pool

　　7, ORA-04091

Feature: Trigger not working properly

Reason: This error occurs when a row triggers a table that reads or modifies a change (is being modified, inserted).

Action: Check the trigger script to ensure referential integrity

　　8, ORA-01242, ORA-01113

Feature: Media failure causes database downtime

Cause: Media failure.

Action: Check the hardware failure, modify the Dbshut script, and modify the startup command to:

Startup Open Recover

Alter Database Open

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