Server Administration :: How To See Whether Table Data Using Compression

1)i have 2 SWP TABLES. while dropping a column, i am getting error -
ORA-39726: unsupported add/drop column operation on compressed tables.

2) when i checked compression status, those were not compressed. But as per our code standard, SWP tables should not be in compress mode.

OWNER TABLE_NAME COMPRESS COMPRESS_FOR
------------------------------ ------------------------------ -------- ------------
NOVAR PAYMENT_SWP DISABLED

OWNER TABLE_NAME COMPRESS COMPRESS_FOR
------------------------------ ------------------------------ -------- ------------
NOVAR PREPAYMENT_SWP DISABLED

3) as a workaround, i compressed these 2 SWP tables with OLTP option, and then i was able to drop the column from these 2 SWP tables.

4) Below statement is correct or not ?
IF A TABLE USING BLOCK LEVEL COMPRESSION, THEN this error will come - ORA-39726: unsupported add/drop column operation on compressed tables.

if above statement is correct, then how to find out whether table data is using block level compression ?

5) we have DBMS_COMPRESSION.GET_COMPRESSION_TYPE. using this i just tried to find out, but i am getting "1" as output. I am not getting the exact meaning of it.

confirm what is the conclusion on this ?

SQL> declare
rid rowid;
n number;
begin
select max(rowid) into rid from NOVAR.PAYMENT_SWP;
n := dbms_compression.get_compression_type('NOVAR','PAYMENT_SWP',rid);
dbms_output.put_line(n);
end;
/
2 3 4 5 6 7 8 9 1

PL/SQL procedure successfully completed.

SQL>
SQL> SET SERVEROUTPUT ON
SQL> /
1

PL/SQL procedure successfully completed.

SQL> SELECT max(rowid) from NOVAR.PAYMENT_SWP;

MAX(ROWID)
------------------
AAsz4fAHSAAAD3IABs

(ii) 2nd table

SQL> set serveroutput on
SQL> declare
rid rowid;
n number;
begin
select max(rowid) into rid from NOVAR.PREPAYMENT_SWP;
n := dbms_compression.get_compression_type('NOVAR','PREPAYMENT_SWP',rid);
dbms_output.put_line(n);
end;
2 3 4 5 6 7 8 9
10 /
1

PL/SQL procedure successfully completed.

SQL> SELECT max(rowid) from NOVAR.INVOICELINE_SWP;

MAX(ROWID)
------------------
AAsz4ZAEkAAAp8XAAA