Yep that does work. Your test works here too. Beginning to look like a bug of some sort. I wrote the cursor out to a table via 'Copy To' and then altered it, and it works too. I also built another select on the table and it altered the cursor just fine.

And I tried taking your example and making it look like my scenario:

CREATE TABLE test2 (f1 c(10), f2 c(10))
APPEND BLANK
SELECT * from test2 INTO CURSOR ctest READWRITE
SELECT * from ctest INTO CURSOR ctest READWRITE
ALTER TABLE ctest drop COLUMN f2

and your example stll worked?

It seems that it works in every case except for the one I wanted it to.
Evidently something deeper is going on. Something is preventing it form working at that particular position in my code.

Error 1115 "invalid operation for the cursor"

For now I guess I will just use the workaround of writing the cursor to disk via COPY TO, then altering the table. But it is a curious incident.

I will need to remove multiple fields and "drop column f1, f2, f3" doesn't work. So I assume I will have to issue multiple alter table commands?

Also, Can I stop alter from creating a backup table? I didnt see any reference to the backup in the help? .TBK.

Thanks