Avoiding "Extract Schema" while using Data Compare option

I am doing a Data compare between tables of 2 different Database. While doing this using ',Compare Data" option , the process takes a lot of time in EXTRACT SCHEMA step ( screen print attached ).

Is there any way we can avoid this step or any other way to improve the performance

Extract schema is scanning database to get objects detail and do preparation for the next step of comparing data.

How big are your two databases? we would like to get more data like the number of tables, views, are there many of foreign keys and the rough time toad take for Exact Schema? those information could help us to evaluate the possibility to improve performance.



In both source and target i have more that 1000 tables. But if i need to compare the data only for 1 table , the extract schema still scans though all the 1000 tables. Is there a way where in i can specify the name of the table before extract schema step so that it only extract the details of that single table and not all 1000 tables.


Nikhil P

Now We don’t support that.

Could I suggest an option?

I have a similar annoyance, especially when ‘fine-tuning’ my comparisons (TDP version 4.3, comparing ~400 tables, Oracle to Postgres). If there were a check box to ‘Reuse Schema Cache’ (the statistics that are repeatedly pulled from the data dictionaries) on the second and subsequent accesses, the customer could control when the schema statistics are reused. This checkbox would be greyed-out during the initial schema stats query.



I have created a enhancement case QAT-13293 to follow it.

Edit: I just realized this is over a year old, but the issue is still present today in version 5.0+ so this may help others like me.

I had this same problem, at my organization we have thousands of databases on some servers and the data compare wizard would just freeze when trying to read all this schema.

A workaround that was found with the help of Quest was to simply query the tables I want to do a data compare for, so that each is now a "result set" from a SQL editor window. I can then easily right click on the result rows and do "compare to" and select my other result set.

This is also the easiest way I have found to make small adjustments when doing a comparison, for example if I am getting every row showing a data difference because one table shows values as "0001" as a string and the other is 1 as int, I can convert to int in my result set and rerun the comparison to resolve this "difference" .

Hope this helps.