Initialisation Parameters

Initialisation Parameters

A single SPFILE for CDB

PDB values change :

- Loaded in memory after PDB close- Store in dictionary after CDB shutdown- Only for parameter ISPDB_MODIFIABLE =TRUE;

CONNECT / AS SYS@PDB1 AS SYSDBA
ALTER SYSTEM SET DDL_LOCK_TIMEOUT=10;
SHOW PARAMETER DDL_LOCK_TIMEOUT;

CONNECT / AS SYS@PDB2 AS SYSDBA

ALTER SYSTEM SET DDL_LOCK_TIMEOUT=20 SCOPE=BOTH;

CONNECT / AS SYSDBA

SELECT VALUE, ISPDB_MODIFIABLE, CON_ID FROM V$SYSTEM_PARAMETER WHERE  NAME='ddl_lock_timeout';

Using ALTER SYSTEM Statement on PDB

AFFECTING CURRENT PDB ONLY:

ALTER SYSTEM FLUSH SHARED_POOL;

ALTER SYSTEM FLUSH BUFFER_CACHE;

ALTER SYSTEM ENABLE / DISABLE RESTRICTED SESSION;

ALTER SYSTEM KILL SESSION

ALTER SYSTEM SET PARAMTER 

ALTER SYSTEM EXECUTING IN A PDB BUT AFFECT THE WHOLE CDB:

ALTER SYSTEM CHECKPOINT; -- Affects all datafiles except those in read only or offline.

ALL OTHER ALTER SYSTEM STATEMENT AFFECT THE WHOLE CDB & MUST BE RUN BY A COMMON USER IN THE CDB ROOT.

ALTER SYSTEM SWTICH LOGFILE; -- this is not allowed from PDB database.