Dbms_output on Oracle Scripts

Redefine a Table Online with DBMS_REDEFINITION, No DML Blocking

Fri, 18 Sep 2026 00:00:00 +0000

Redefine a Table Online with DBMS_REDEFINITION, No DML Blocking

Purpose

A DBA moving a table to a new tablespace, adding compression, or rebuilding a badly fragmented segment has one hard requirement: users can't lose access to that table while the change is happening. For decades the available tools — CREATE TABLE AS SELECT plus a rename, or a plain ALTER TABLE MOVE — all lock the table for at least part of the operation, even if only briefly. DBMS_REDEFINITION restructures a table while it stays fully readable and writable the entire time.

Oracle: Find Tables with Outdated Statistics via DBA_TABLES

Tue, 01 Jul 2025 00:00:00 +0000

Oracle Database Query: Find Tables with Outdated Statistics

Purpose

This Oracle Database query helps database administrators monitor the progress of table statistics collection by identifying tables that have analyze dates older than the current date. It's particularly useful when running large-scale ANALYZE operations and you need to track how many tables still require statistics updates.

This is useful if you are running an analyze and want to see how much is left to do

Oracle Active SQL: Monitor Sessions with v$session

Sun, 31 Dec 2023 00:00:00 +0000

Show all Active SQL for Sessions using v$session and v$sqlarea

Gain real-time insights into currently active user sessions and the SQL statements they are executing to troubleshoot performance issues and optimize resources

SQL Code

 1set feedback off
 2set serveroutput on size 9999
 3column username format a20
 4column sql_text format a55 word_wrapped
 5begin
 6 for x in
 7 (select username||'('||sid||','||serial#||') ospid = '|| process ||
 8 ' program = ' || program username,
 9 to_char(LOGON_TIME,' Day HH24:MI') logon_time,
10 to_char(sysdate,' Day HH24:MI') current_time,
11 sql_address,
12 sql_hash_value
13 from v$session
14 where status = 'ACTIVE'
15 and rawtohex(sql_address) <> '00'
16 and username is not null ) loop
17 for y in (select sql_text
18 from v$sqlarea
19 where address = x.sql_address ) loop
20 if ( y.sql_text not like '%listener.get_cmd%' and
21 y.sql_text not like '%RAWTOHEX(SQL_ADDRESS)%' ) then
22 dbms_output.put_line( '--------------------' );
23 dbms_output.put_line( x.username );
24 dbms_output.put_line( x.logon_time || ' ' || x.current_time || ' SQL#=' || x.sql_hash_value);
25 dbms_output.put_line( substr( y.sql_text, 1, 250 ) );
26 end if;
27 end loop;
28 end loop;
29end;

Sample Oracle Output

1no rows selected
2SQL>

Purpose: