ORA-02096: specified initialization parameter is not modifiable with this option

Since version 11g must use the DEFERRED clause. It means it takes effect in subsequent sessions.

You must exit from current session to get the new settings

SQL Profile

When you run SQL Tuning Advisor, sometimes you can see findings for SQL Profile:
1- SQL Profile Finding (see explain plans section below)
--------------------------------------------------------
  A potentially better execution plan was found for this statement.


  Recommendation (estimated benefit: 99.99%)
  ------------------------------------------
  - Consider accepting the recommended SQL profile.
    execute dbms_sqltune.accept_sql_profile(task_name => 'staName61543', task_owner => 'PWRLINE', replace => TRUE);

12c Query Against Dictionary Views slow

Doc ID 1292253.1

SQL> purge recyclebin; --if you have DBA access, purge dba_recyclebin;
SQL> EXEC DBMS_STATS.GATHER_TABLE_STATS(OWNNAME =>'SYS', TABNAME => '$KTFBUE',ESTIMATE_PERCENT=>100);
SQL> EXEC DBMS_STATS.GATHER_SCHEMA_STATS('SYS');
SQL> EXEC DBMS_STATS.GATHER_FIXED_OBJECTS_STATS(NO_INVALIDATE => FALSE);

Rman Duplicate database from Active database

From 11g above, you can use rman to duplicate database from an active database instead of from a backup.
Two big disadvantages of the ACTIVE database duplication method are:

·         Negative performance impact on the source database. This impact applies to the whole duplication time.

·         High network traffic on the connection between the source and target databases.

Test envorinment:

Source

     SID: testprd

     host:192.168.96.3

Target

     SID: testrman

      host: 192.168.96.4

Oracle 10/11 install on Centos 7

For 10.2.0.1:

If you get error
“Error in invoking target 'collector' of makefile '/orasw/app/oracle/product/10.2.0/sysman/lib/ins_emdb.mk'” at 83% can be ignored (Metalink 957982.1)

For 11.2.0.4:

If you get the following error:

PRVF-7532 : Package "pdksh" is missing on node "Hostname"
You can install ksh package (yum install ksh)then safely ignore it and  continue.

When getting error “Error in invoking target 'agent nmhs' of makefile '/orasw/app/oracle/product/11.2.0/sysman/lib/ins_emagent.mk'.”

vi $ORACLE_HOME/sysman/lib/ins_emagent.mk
Search for the line
$(MK_EMAGENT_NMECTL)
Change it to:
$(MK_EMAGENT_NMECTL) -lnnz11

And retry.

RAC: ORA-01410: invalid ROWID

Can try flushing the cache:
alter system flush buffer_cache;

ORA-03114 and ORA-03137

Oracle Version: 11.2.0.1
Client sessions disconnected due to error "ORA-03114: Not Connected to Oracle".
In Alert log ORA-03137 is detected: "ORA-03137: TTC protocol internal error : [12333] [8] [57] [48] [] [] [] [] ".