CHAIN_CNT > 0. Why?

I have some tables for which CHAIN_CNT (after ANALYZE) is > 0;

OWNER TABLE_NAME AVG_ROW_LEN NUM_ROWS CHAIN_CNT NUM_COLS

--------------- -------------------- ----------- ---------- ---------- -----
---
FIN          BIN_LOCATIONS                191     101028        689       40
FIN          DESPATCH_HEADERS             514     215763       7800       58
FIN          GEM_FACILITIES               375       8439         34       13
FIN          GL_ACCOUNT_BALANCES          345      24358         21       55
FIN          SALES_CREDIT_NOTES           456      13031        102       84
FIN          SYS_PRODUCT_LANGUAGE          57      48343        141        6
IPS           IFA_CUST_PROFILE             266       1160         19

7 rows selected.

Why is it so?
- All character columns are fixed length so that can't change with an update

• Number of columns range from 6 to 84
• Row lengths is a lot less than my 8k Oracle blocks

Are number columns like NUMBER(20,2) stored in such a way that the space occupied will vary with the value therein?

If not, what should I watch for, as a cause for these rows to be migrated/chained ?
Could not find much more in the docs so far.

Thanks

Pls don't flame about Oracle version - I'm migrating to 817 or 9.2 as soon as my software vendor allows.

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OpenVMS 7.3-1, Oracle 8.1.6.0

Syltrem
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