Getting error "ORA-54033" when calling a procedure - database

Question

I'm currently getting the following Oracle error when calling a procedure:
ORA-54033: column to be modified is used in a virtual column
expression
How can I track down the root cause of this error?

Answer 1

To find the table and column names of all virtual columns in your database you can run the following query:
SELECT c.OWNER, c.TABLE_NAME, c.COLUMN_NAME
FROM DBA_TAB_COLS c
WHERE c.VIRTUAL_COLUMN = 'YES' AND
c.OWNER NOT IN ('SYS', 'XDB')
ORDER BY c.OWNER, c.TABLE_NAME, c.COLUMN_NAME;
And you can use the following script to dump the DDL of all tables in your database which contain virtual columns to DBMS_OUTPUT:
DECLARE
lobDDL CLOB;
PROCEDURE dump_clob(aCLOB IN CLOB) IS
nCLOB_length NUMBER;
nCLOB_offset NUMBER := 1;
nMax_chunk_size NUMBER := 32767;
strChunk VARCHAR2(32767);
BEGIN
nCLOB_length := DBMS_LOB.GETLENGTH(aCLOB);
WHILE nCLOB_offset <= nCLOB_length LOOP
strChunk := DBMS_LOB.SUBSTR(aCLOB, nMax_chunk_size, nCLOB_offset);
DBMS_OUTPUT.PUT(strChunk);
nCLOB_offset := nCLOB_offset + LENGTH(strChunk);
END LOOP;
DBMS_OUTPUT.PUT_LINE(';');
END dump_clob;
BEGIN
FOR aRow IN (SELECT DISTINCT c.OWNER, c.TABLE_NAME
FROM DBA_TAB_COLS c
WHERE c.VIRTUAL_COLUMN = 'YES' AND
c.OWNER NOT IN ('SYS', 'XDB')
ORDER BY c.OWNER, c.TABLE_NAME)
LOOP
lobDDL := DBMS_METADATA.GET_DDL(object_type => 'TABLE',
name => aRow.TABLE_NAME,
schema => aRow.OWNER);
dump_clob(lobDDL);
END LOOP;
END;

Answer 2

I got the same error and fixed it by doing as below.
Get the hidden columns with its dependent columns using the below.
SELECT COLUMN_NAME, DATA_DEFAULT, HIDDEN_COLUMN
FROM USER_TAB_COLS
WHERE TABLE_NAME = 'YOUR_TABLE_NAME';
You should see something like this below:
SYS_STUMF_$2WEF286CDZ1WPC4V_F5 |SYS_OP_COMBINED_HASH("ID","FIRST_NAME","ANOTHER_COLUMN_NAME") | YES
Drop this hidden column by using the above column names used by it.
exec dbms_stats.drop_extended_stats(user, 'YOUR_TABLE_NAME', '("ID","FIRST_NAME","ANOTHER_COLUMN_NAME") ');
Now run your procedure or alter your columns.
alter table YOUR_TABLE_NAME modify (ID VARCHAR2(10));
Create the hidden column again:
exec dbms_stats.create_extended_stats(user, 'YOUR_TABLE_NAME', '("ID","FIRST_NAME","ANOTHER_COLUMN_NAME")');

Answer 3

I am just sharing my experience here with this issue.
My table has the below virtual column. There are other columns as well, and I am just adding the impacted columns here.
Create Table Virtual_test
(ColumnA varchar2(100),
CLEAN_ColumnA VARCHAR2(4000 BYTE) GENERATED ALWAYS
AS(GET_CLEAN_ColumnA(ColumnA)) VIRTUAL
);
Now when I want to modify the size of ColumnA:
Alter Table Virtual_test
MODIFY ColumnA varchar2(255);
ORA-54033: column to be modified is used in a virtual column expression.
exec dbms_stats.drop_extended_stats(USER,'Virtual_test','(GET_CLEAN_ColumnA(ColumnA))' );
Alter Table Virtual_test
MODIFY ColumnA varchar2(255);
One major mistake I did was this virtual column was not hidden and not system generated in my table.
The step dbms_stats.drop_extended_stats deleted my existing column and
dbms_stats.create_extended_stats will create an invisible column with the system generated name.
So I think this won't work with a non-hidden column, and you may need to follow the below steps and drop the column.
Alter Table Virtual_test drop column CLEAN_ColumnA;
Alter Table Virtual_test
MODIFY ColumnA varchar2(255);
Alter Table Virtual_test add
CLEAN_ColumnA VARCHAR2(4000 BYTE) GENERATED ALWAYS
AS(GET_CLEAN_ColumnA(ColumnA)) VIRTUAL;

Answer 4

The virtual column names starting with 'SYS_ST%' are indeed belonging to extended statistics... and since Oracle 12c, the system is trying to recognize and create them automatically...
Just google for "Oracle 12c Automatic Column Group Detection".