Wednesday, January 10, 2024

ORA-56747: invalid value ... for parameter sga_target


SQL> alter system set sga_target=4257m; 

alter system set sga_target=4257m 

* 

ERROR at line 1: 

ORA-02097: parameter cannot be modified because specified value is invalid 

ORA-56747: invalid value 4463788032 for parameter sga_target; must be smaller 

than parameter sga_target of the root container 

Tuesday, November 28, 2023

ORA-02149: Specified partition does not exist

If you are performing a datapump export and you are returned following error for one or more tables, this means that probably a simultaneous partition maintenance operation is in progress during this time this table was accessed for export.  ORA-31693, ORA-02354, ORA-02149

ORA-31693: Table data object "<TABLE_OWNER>."<TABLE_NAME>":"<PARTITION_NAME>" failed to load/unload and is being skipped due to error: 

ORA-02354: error in exporting/importing data 

ORA-02149: Specified partition does not exist 

Saturday, November 25, 2023

RMAN-20208: UNTIL CHANGE is before RESETLOGS change

If you are performing a SCN or time based recovery and RMAN-20208 is returned, It means that there was a SCN or time-based recovery previously done after which database was opened with reset logs, and now database has a new incarnation number. If you once again want to perform a recovery for any reason, or previously done incomplete recovery was not until the point where we wanted database to be, you need to reset the incarnation of the database and repeat the incomplete recovery process. 

Friday, November 3, 2023

Database Point in Time Recovery of a Pluggable Database and Conventional Databases

Starting 12c with the introduction of pluggable databases, we can perform point-in-time recovery either at CDB (container database) level or at individual pluggable databases level, in a multi-container CDB. CDB level recovery is same as conventional database point-in-time recovery that existed prior to 12c. In this document I will explain how to perform point-in-time recovery of a CDB (that could be a non-container database, or a multi-container database with one or more PDBs); and also, recovery of an individual PDB in a multi-container CDB database.  

Thursday, October 5, 2023

Performing Flashback Restore using SCN or Time

This document explains how to enable database flashback, creating restore points and performing recovery using guaranteed restore point. In the following I will explain how we can perform a time based, or SCN based flashback restore. Before proceeding further, make sure that flashback is enabled, and flashback logs are also getting created in the fast recovery area. Flashback logs are managed automatically, and oldest flashback logs are purged by oracle if there is a space crunch sensed in the fast recovery area. Oracle will try to keep flashback logs until the time (in the past) specified in the parameter db_flashback_retention_target. However, this value is only a soft limit and specified in minutes.

Monday, August 21, 2023

ORA-16789: standby redo logs configured incorrectly

Creating standby redo log files is a recommended way of configuring dataguard in Oracle database environment. If there is any discrepancy found in standby redo log configuration, you might face ORA-16789 warning. While checking status of dataguard configuration through DGMGRL command, following is that you might see as an example, in a dataguard broker configuration.

Thursday, August 10, 2023

ORA-12578: TNS:wallet open failed

 

[oracle]$ sqlplus
 
SQL*Plus: Release 12.1.0.2.0 Production on Fri Apr 14 08:50:59 2023
 
Copyright (c) 1982, 2014, Oracle.  All rights reserved.
 
Enter user-name: sys as sysdba
Enter password:

Sunday, June 25, 2023

ORA-16000: database or pluggable database open for read-only access

 I faced this error message when I tried to drop a table from my PDB which was opened in read-write mode without any restriction.

SQL> drop table test;
drop table test
           *
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-16000: database or pluggable database open for read-only access
 
 SQL> show pdbs
 
CON_ID    CON_NAME         OPEN MODE        RESTRICTED
---------- ------------------------------ ---------- ---------------------------
 3                PDB1                      READ WRITE      NO

Saturday, June 10, 2023

ORA-65179: cannot keep datafiles for a pluggable database that is not unplugged

You should use “including datafiles” clause while dropping a pluggable database otherwise ORA-65179 would be returned

SQL> drop pluggable database testpdb;
drop pluggable database testpdb
*
ERROR at line 1:
ORA-65179: cannot keep datafiles for a pluggable database that is not unplugged


Saturday, June 3, 2023

ORA-65342: source pluggable database has unrecovered transaction

Starting 12.2, if you are planning to clone a PDB locally or remotely, you can do that while source PDB is open in read-write mode (hot cloning). In 12.1, if you start your CREATE PLUGGABLE DATABASE command while a transaction is already active in the source PB, you will be returned ORA-65342. Therefore, the better option is to close the source PDB, and then start it as read-only so that no transactions could hinder the cloning process

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