|
||||
|
Starting/Stopping CDB and PDBs The traditional approach of starting and stopping databases is now only valid for CDB. So in order to start and stop CDB you will use the familiar startup and shutdown commands. PDBs don’t get automatically started with CDB. Even if your CDB is up and running it is possible […] From 12c onwards, Oracle 12c introduced truncate with cascade so when truncate operates on master table the child table rows also get truncated automatically. SCOTT@PDB > create table MASTER ( 2 ID number generated always as identity PRIMARY KEY, 3 NAME VARCHAR2(20) 4 ); Table created. SCOTT@PDB > create table CHILD ( 2 ID […] In a container architecture, the parameters for PDB will inherit from the root database. That means if statistics_level=all in the root that will cascade to the PDB databases. You can over ride this by using Alter system set, if that parameter is pdb modifiable, there is a new column in v$system_parameter for the same. The […] Here is the filtered tables after comparison of 11g with 12c Background Processes. Name Expanded Name Short Description Long Description External Properties AQPC AQ Process Coordinator Per instance AQ global coordinator AQPC is responsible for performing administrative tasks for AQ Master Class Processes including commands like starting, stopping, and other administrative tasks. This process is […] Architecture of Data dictionary in view of multiple containers in a Single SGA The above diagram requires a explanation. Data Dictionary A data dictionary resides in CDB is shared (definitions) between CDB & PDB, for those objects that are system (internal) For example: AWR is global, TAB$, OBJ$ etc.A data dictionary objects or […] Before to 12c, when using a single database the user management is pretty straight , create a user and assign the privileges or roles and manage it. In view of multitenant architecture, where multiple databases exists managing multiple databases with a single users can be cumbersome, For example you a host that hosts 10 applications […] Hi, In view of multiple databases sharing single SGA how to distinguish which database you will need to see. Now all dynamic views has two new columns for example:- V$process SQL> desc v$process Column Datatype ADDR RAW(4 | 8) PID NUMBER SOSID VARCHAR2(24) SPID VARCHAR2(24) STID VARCHAR2(24) EXECUTION_TYPE VARCHAR2(10) PNAME VARCHAR2(5) USERNAME VARCHAR2(15) SERIAL# NUMBER […] Here is the list of deprecated parameters as of 12.1.0.1 SQL> SELECT name from v$parameter WHERE isdeprecated = ‘TRUE’ ORDER BY name; active_instance_count background_dump_dest buffer_pool_keep buffer_pool_recycle commit_write cursor_space_for_time fast_start_io_target global_context_pool_size instance_groups lock_name_space log_archive_local_first log_archive_start max_enabled_roles parallel_automatic_tuning parallel_io_cap_enabled parallel_server parallel_server_instances plsql_v2_compatibility remote_os_authent resource_manager_cpu_allocation sec_case_sensitive_logon serial_reuse sql_trace standby_archive_dest user_dump_dest Until 12c we cannot restrict the PGA memory, even though you set pga_aggregate_target its just a soft limit, sessions can go beyond that. However, we can restrict PGA using PGA_AGGREGATE_TARGET parameter and limiting the memory access, This is extremely useful in consolidated databases running on a host, but again the baseline should be done before […] Starting 12c you can make columns invisible as like you make indexes invisible. The following actions can be applicable on invisible columns SELECT * FROM statements in SQL DESCRIBE commands in SQL*Plus %ROWTYPE attribute declarations in PL/SQL Describes in Oracle Call Interface (OCI) Few Notes:- When using select, when you dont select the […] |
||||
Oracle 23c New Features for DBA's
Follow Me!!!