Schema Compare doesn't generate script for table diffs


In, I have a source schema consisting of this table:

CREATE TABLE toad_compare_test (col1 NUMBER, col2 NUMBER);

In another DB, I have a target schema with this table:

CREATE TABLE toad_compare_test (col1 NUMBER);

In Schema Compare, it finds the difference, and allows me to preview that difference, but the Sync Script tab is blank (except for comments).

Strangely, this is also the same for me in 13.1 GA (can't get the exact version ATM).

Thoughts? I use this at least monthly, and I don't recall having this issue before, but scanning back in the forums, I've forgotten about more than 1 issue I've posted.... :thinking:


Hi Rich,

Sorry for the delay...I was on vacation. I just tested this and it's working OK for me. At first I suspected something to do with the "Add/Reorder columns using DBMS_REDEFINITION" but it works for me with that option either checked or unchecked.

Does your "real" table have any other differences?

And sorry to ask a dumb question, didn't uncheck the table or column in the "difference details" tree, did you? That would cause it to not appear in the sync script.


Hey John,

Welcome back!

Once I edited my CONFIG.SYS to move my mouse driver to himem and load EMM386.EXE and rebooted, it works!

OK, not really. I have no idea why it works now or what I did, other than a non-related reboot for Windows patching. I can't duplicate it anymore, and since my Win7™ laptop is being replaced with something Win10ish, one can only deduce that there is code in Toad to determine if you're on vacation and to break if that condition is true.

Thanks much! Hope it was a fun, relaxing, and refreshing time away from us troublemakers! :slight_smile:


1 Like

Sounds like job security to me! Glad it's working again.

I've the same problem in the latest beta. I added 3 more columns after the last column of a table, and checked Tables|Add/Reorder columns with DBMS_REDEFINITON option. Toad finds the differences, but there is no individual ALTER TABLE ADD COLUMN commands in sync script , just a dbms_redefiniton script for the whole table. I don't think Toad should generate this type of script in this situation.

Hi Tamas,

That sounds different than Rich's problem, but you are right - ALTER TABLE ADD COLUMN is what Toad should do in this situation. As a workaround until I fix it, uncheck the dbms_redef option.

Update 12/9/2019: Fixed in Toad for Oracle 13.3 Beta