Identifying Oracle Tables with Migrated/Chained Rows

The following code generated the report on migrated/chained rows. Note that the use of this script is predicated on the use of Oracle’s ANALYZE command to populate the chain_cnt and num_rows columns of the dba_tables data dictionary view.

spool chain.lst;
set pages 9999;
column c1 heading "Owner" format a9;
column c2 heading "Table" format a12;
column c3 heading "PCTFREE" format 99;
column c4 heading "PCTUSED" format 99;
column c5 heading "avg row" format 99,999;
column c6 heading "Rows" format 999,999,999;
column c7 heading "Chains" format 999,999,999;
column c8 heading "Pct" format .99;
set heading off;
select 'Tables with migrated/chained rows and no RAW columns.' from dual;
set heading on;
select
owner c1,
table_name c2,
pct_free c3,
pct_used c4,
avg_row_len c5,
num_rows c6,
chain_cnt c7,
chain_cnt/num_rows c8
from dba_tables
where
owner not in ('SYS','SYSTEM')
and
table_name not in
(select table_name from dba_tab_columns
where
data_type in ('RAW','LONG RAW')
)
and
chain_cnt > 0
order by chain_cnt desc
;