Re: Oracle 9.2.0.7/10g -> ODBC -> MySQL

[marco.dejonge]

Hello Imanol,

We're running into a similar problem. Our setup:
- Oracle Database 10.1 (Using HS Generic connectivity)
- MySQL Database 4.0.16
- MySQL ODBC Driver 3.51.12. ODBC Settings that are selected:
* Enable dynamic cursor
* Don't cache results (forward only cursor)
* Return table names for SQLdescrive
* Force use of forward only cursor
- OS: Windows 2003 Server

If we now lauch a select from Oracle to MySQL, we get "ORA-28511: lost RPC connection to heterogeneous remote agent". I've been able to isolate the issue to the ODBC option "Don't cache results". If you deselect this, it works fine, BUT...then there is another issue (I'll describe this bellow). If we could get this to work, that issue might become irrelevant.

My question: have you been able to get passed the above ORA-28511? If so, could you put us on the right track(?). Thx!

Best regards,

Marco de Jonge

Other issue:
- Basiscally it is a connection time out with MySQL, the reason (we can come up with + empirical experience) for this however is a bit more complex.
- If we try to run a query like "SELECT xxx FROM big_table WHERE a = 1", the WHERE part is dropped for making the cursor declaration (as far as we can tell) AND all data is pulled over. Because it is a select from a big_table ===> takes a while ===> connection timeout.
- Empirical evidence: You can just see the hsodbc proces taking up internal memory when launching the query. If we make the table smaller (in # lines), we get it to work. Hence, we would like to get the "Don't cache results" to work...