Chained & Migrated Rows.

I was checking a table for potential chaining / migration:-

First I checked the chained_row table was clear.

select count(*) from chained_rows;

  COUNT(*)
----------
         0

SQL> analyze table maximo.workorder list chained rows;

Table analyzed.

SQL> select count(*) from chained_rows;

  COUNT(*)
----------
    170898

SQL> select count(*) from maximo.workorder;

  COUNT(*)
----------
    546285

Showing 1 in 3 rows chained migrated.

yet when I check dba_tables as follows:-

SQL> SELECT table_name,chain_cnt,
  2         round(chain_cnt/num_rows*100,2) pct_chained,
  3         avg_row_len, pct_free , pct_used
  4    FROM dba_tables
  5  WHERE table_name = 'WORKORDER'
  6  AND OWNER='MAXIMO';

it shows a chain count as zero:-