Initialization Parameter

How to Change NLS_LENGTH_SEMANTICS Temporarily

by Ed Chen
May 19, 2021March 23, 2021

NLS_LENGTH_SEMANTICS Let's see what NLS_LENGTH_SEMANTICS of the database currently set. SQL> conn hr/hr@orclpdb Connected. SQL> show parameter semantics; NAME … Read More »

Complete Initialization Parameters List in DBCA 19c

by Ed Chen
October 31, 2020October 19, 2020

The complete list is shown during creating a 19c RAC database by DBCA.

How to Resolve ORA-01000: maximum open cursors exceeded

by Ed Chen
January 15, 2020March 21, 2021

ORA-01000 Saw an error ORA-01000: maximum open cursors exceeded when executing a lot of statements. It seemed that the number of open cursors has reached… Read More »

How to Resolve ORA-02085: database link SOURCE_LINK connects to SOURCE_DATABASE

by Ed Chen
December 19, 2016August 15, 2019
2 Comments

ORA-02085 I created a database link without any problem. But when I tried to test the link, I got ORA-02085. SQL> select sysdate from dual@source_link;… Read More »

UNDO_RETENTION, How and Why

by Ed Chen
April 7, 2016November 1, 2019

UNDO_RETENTION At times, you may find out or feel that UNDO_RETENTION is useless at all. Raising the number of seconds cannot resolve ORA-01555. This is… Read More »

Timings to Set SESSIONS Explicitly

by Ed Chen
July 5, 2014May 17, 2019

DBAs usually set PROCESSES when initializing a new database:SQL> alter system set processes=3000 scope=both;System altered.Another important parameter SESSIONS will be derived from PROCESSES automatically in this… Read More »

How to Resolve ORA-00845: MEMORY_TARGET not supported on this system

by Ed Chen
January 2, 2013April 1, 2018

If you are planning to install additional database by DBCA on a Linux server, you should notice not only the limitation of semaphores, but also… Read More »

BYTE vs CHAR in NLS_LENGTH_SEMANTICS

by Ed Chen
December 12, 2012November 5, 2019

BYTE vs CHAR in NLS_LENGTH_SEMANTICS Most of databases set NLS_LENGTH_SEMANTICS as BYTE by default, but there are some databases in Non-English country will take CHAR… Read More »

How to Resolve ORA-02097: Parameter Cannot be Modified Because Specified Value is Invalid

by Ed Chen
December 9, 2012May 16, 2019

When you ALTER SYSTEM to modify an initialization parameter, it sometimes fails with ORA-02097 ORA-02097: parameter cannot be modified because specified value is invalid Reproduce… Read More »

How to Archive Redo Logs to Respective Local Destinations of RAC

by Ed Chen
December 4, 2012March 29, 2018

For a RAC database, we may want to archive the redo logs to local destinations of instances rather than ASM. That is, put instance #1,… Read More »