Oracle Chained Rows
Version 12.1.0.2

Library Note Morgan's Library Page Footer
The Library is currently in the process of being upgraded from Oracle Database Version 11.2.0.3 to 12.1.0.1. Demos are being upgraded to reflect the new Container paradigm as well as EBR (Edition Based Redefinition) and may contain references to CDBs, PDBs, and other objects you may not be familiar with such as CDB_OBJECTS_AE: Welcome to 12c.
 
Manufacturing Chained Rows
Courtesy of Andy Hassall conn / as sysdba

show parameter db_block_size

conn uwclass/uwclass

SQL> @?/rdbms/admin/utlchn1.sql

CREATE TABLE t (
col1  VARCHAR2(4000),
col2  VARCHAR2(4000));

INSERT INTO t VALUES ('x', '1');
INSERT INTO t VALUES ('xx', '2');

INSERT INTO t
(col1, col2)
VALUES
(LPAD('x',4096,'x'), LPAD('x',4096,'x'));

INSERT INTO t VALUES ('xxxx', '4');
INSERT INTO t VALUES ('xxxxx', '5');
COMMIT;

ANALYZE TABLE t LIST CHAINED ROWS INTO chained_rows;

set linesize 121
col table_name format a15
col head_rowid format a20

SELECT sys_op_rpb(rowid), table_name, head_rowid, analyze_timestamp
FROM chained_rows;

SELECT rowid, dbms_rowid.rowid_block_number(rowid) BN, sys_op_rpb(rowid), length(col1), length(col2)
from t;

SELECT table_name, chain_cnt
FROM user_tables
ORDER BY 1;

ANALYZE TABLE t COMPUTE STATISTICS;

SELECT table_name, chain_cnt
FROM user_tables
ORDER BY 1;

Related Topics
Analyze
DBMS_IOT
Tables

Morgan's Library Page Footer
This site is maintained by Dan Morgan. Last Updated: This site is protected by copyright and trademark laws under U.S. and International law. © 1998-2014 Daniel A. Morgan All Rights Reserved