The Task
In the initial phases of your evaluation of the Mertech SQL solution for migrating Btrieve to SQL, you probably want to compare and contrast your application running against Btrieve and against SQL. Perhaps you want to compare dialogs or reports to ensure the data is all looking the same; or you may want to compare speed.
An Answer
I’ll describe here a technique that will allow you to run your application against the original Btrieve data and against MSSQL and Oracle all at the same time so you can easily compare the screens, reports, etc.
Consider the Pervasive Function Executor as your application and the demodata as the application’s data. You might have an installation directory looking like this:
Directory of C:\MyApp
11/10/2009 03:08 PM <DIR> .
11/10/2009 03:08 PM <DIR> ..
06/09/2005 08:59 PM 42,496 w3btrv7.dll
06/10/2005 12:00 AM 162,816 wdbuui32.dll
06/09/2005 10:59 PM 950,784 WBEXEC32.exe
05/31/2009 09:33 PM 151,552 FIELD.DDF
05/31/2009 09:33 PM 81,920 FILE.DDF
05/31/2009 09:33 PM 90,112 INDEX.DDF
05/31/2009 09:33 PM 401,408 BILLING.MKD
05/31/2009 09:33 PM 135,168 CLASS.MKD
05/31/2009 09:33 PM 94,208 COURSE.MKD
05/31/2009 09:33 PM 90,112 DEPT.MKD
05/31/2009 09:33 PM 1,052,672 ENROLLS.MKD
05/31/2009 09:33 PM 98,304 FACULTY.MKD
05/31/2009 09:33 PM 1,077,248 PERSON.MKD
05/31/2009 09:33 PM 106,496 ROOM.MKD
05/31/2009 09:33 PM 290,816 STUDENT.MKD
05/31/2009 09:33 PM 81,920 TUITION.MKD
16 File(s) 4,908,032 bytes
We see your application (wbexec32.exe), the Btrieve access dll (w3btrv7.dll), the data definitions (*.ddf) and the data files (*.mkd).
Once you migrate the data to the SQL backend of choice, each data file will have a corresponding .INT file. The original Btrieve data and ddf files are not needed for deployment on SQL.
Adding Microsoft SQL to the Picture
To make a side-by-side test that uses SQL access, you can run a script like this (or do it manually in Windows Explorer) from the C:\MyApp command prompt:
mkdir ..\MyApp_mssql
copy *.dll ..\MyApp_mssql
copy *.exe ..\MyApp_mssql
move *.int ..\MyApp_mssql
Now, replace the w3btrv7.dll in c:\MyApp_mssql with the version from
Mertech Data Systems\DB Drivers\Btrieve\deploy\mssql. You have a directory like this:
Directory of C:\MyApp_mssql
11/11/2009 07:51 AM <DIR> .
11/11/2009 07:51 AM <DIR> ..
10/07/2008 04:42 PM 1,332 sql_btr.cfg
10/29/2009 12:50 PM 771,584 w3btrv7.dll
06/10/2005 12:00 AM 162,816 wdbuui32.dll
06/09/2005 10:59 PM 950,784 WBEXEC32.exe
10/23/2009 04:00 PM 2,404 BILLING_MKD.INT
10/23/2009 04:00 PM 2,644 CLASS_MKD.INT
10/23/2009 04:00 PM 1,407 COURSE_MKD.INT
10/23/2009 04:00 PM 1,579 DEPT_MKD.INT
10/23/2009 04:00 PM 1,285 ENROLLS_MKD.INT
10/23/2009 04:00 PM 2,426 FACULTY_MKD.INT
10/23/2009 04:20 PM 7,306 PERSON_MKD.INT
10/23/2009 04:00 PM 1,815 ROOM_MKD.INT
10/23/2009 04:00 PM 2,460 STUDENT_MKD.INT
10/23/2009 04:00 PM 1,576 TUITION_MKD.INT
14 File(s) 1,911,418 bytes
Adding Oracle to the Picture
Do this same process for Oracle — migrate the application data to Oracle using BTR2SQL. This again generates the INT files (which are specific to the backend targeted). Create a third copy of the application folder:
mkdir ..\MyApp_oracle
copy *.dll ..\MyApp_oracle
copy *.exe ..\MyApp_oracle
move *.int ..\MyApp_oracle
Now, replace the w3btrv7.dll in c:\MyApp_oracle with the version from
Mertech Data Systems\DB Drivers\Btrieve\deploy\oracle. You have a directory listing like this:
Directory of C:\MyApp_oracle
11/11/2009 07:50 AM <DIR> .
11/11/2009 07:50 AM <DIR> ..
10/21/2005 02:17 PM 1,332 ora_btr.cfg
10/29/2009 01:01 PM 694,784 w3btrv7.dll
06/10/2005 12:00 AM 162,816 wdbuui32.dll
06/09/2005 10:59 PM 950,784 WBEXEC32.exe
11/10/2009 03:15 PM 2,474 BILLING_MKD.INT
11/10/2009 03:15 PM 2,729 CLASS_MKD.INT
11/10/2009 03:15 PM 1,461 COURSE_MKD.INT
11/10/2009 03:15 PM 1,637 DEPT_MKD.INT
11/10/2009 03:15 PM 1,286 ENROLLS_MKD.INT
11/10/2009 03:15 PM 2,522 FACULTY_MKD.INT
11/10/2009 03:15 PM 7,559 PERSON_MKD.INT
11/10/2009 03:15 PM 1,940 ROOM_MKD.INT
11/10/2009 03:15 PM 2,461 STUDENT_MKD.INT
11/10/2009 03:15 PM 1,603 TUITION_MKD.INT
14 File(s) 1,835,388 bytes
Running All Three at the Same Time
Create a shortcut to each edition of the application. Now you can run each of them separately or at the same time. Since the access dll is in the directory with the application, it will use this method of data access (Btrieve, MSSQL, or Oracle).
Accessing the Files with B_OPEN
Remember, your application is to run unchanged – no changes to the code, directory structures, etc. So, it will request to open data files with the same filename as before, even though they don’t exist. Normally you don’t have to worry with this because the application will just do this. But since we are using Function Executor here as an example and it allows you to open any Btrieve file, it might be confusing.
Consider billing.mkd – before, you would run wbexec32.exe with c:\MyApp as the current directory (the Start In folder). Using the Open dialog, you would request to open “billing.mkd”.
Even though billing.mkd does not exist in the MyApp_mssql folder, when you run wbexec from this location, you still request to open “billing.mkd”; Function Executor will complain that the file doesn’t exist. Click Ignore and the Mertech driver will read billing_mkd.int and know how to handle the request.
Conclusion
With the technique described here, you should be able to run your application against multiple server backends simultaneously, allowing you to compare screen dialogs, reports, and overall application responsiveness.
The example here is using a very simple application and dataset, your application may require extra steps (component registrations perhaps) in order to work in a different directory location.
Riaz Merchant: Oct 28, 2024 6:12:41 AM
Mertech: Jul 6, 2024 12:30:00 PM
Thomas Oatman