Performance problem with slow VIEW from JDBC (fast from SQL Developer)

Question

Hi all,
I'm experiencing following problem and would like to know if someone else also hit this one before and has a suggestion how to solve it:
I have a pretty complicated SELECT statement that per definition returns only a few rows (~30). With no further optimization it takes ~20 seconds to return the full dataset in Oracle SQL Developer. If you add the */+ PUSH_PRED(name_of_some_inner_view) /* hint (hint is correct, stars got eaten by the OTN-forum syntax), the statement takes less than 0.5s to execute (still in SQL Developer). I saved the statement with the hint as VIEW. Selecting from the VIEW in SQL Developer is also fast.
Now if I call the statement from JDBC (Tomcat webapp), I can see from the server console that the statement is 1:1 100% the same as the one I execute in SQL Developer. Nevertheless it takes about 20 seconds to complete.
Here my details:
SELECT banner FROM v$version;
BANNER                                                                        
Oracle Database 11g Express Edition Release 11.2.0.2.0 - Production             
PL/SQL Release 11.2.0.2.0 - Production                                          
CORE     11.2.0.2.0     Production                                                        
TNS for 32-bit Windows: Version 11.2.0.2.0 - Production                         
NLSRTL Version 11.2.0.2.0 - Production                                          
JDBC Driver used: some old odbc14.jar as well as current odbc6.jar for 11.2.0.2.0 from http://www.oracle.com/technetwork/da...10-090769.html
SQL Developer: current version 3.2.20.09From my reading this could go wrong:
- JDBC doesn't know the VIEW's column data types and Oracle behaves mysterious because of this (=there must be more to the SELECT than just the string, some meta-information)
- For some reason the hint inside the VIEW is not used (unlikely)
I also tried a Table Function/Pipelined table and selected from it as a workaround, but the result is the same: Selecting from Function is fast from SQL Developer, but slow from JDBC. All other statements that come from JDBC are as fast as they should be. I really don't know what to think of this and where the error might be.
Is there some setting that tells Oracle not to use hints when called from JDBC?
Thank you & Best regards,
Blama

Answer 1

Hi Bawer,
that's what I'm thinking. Unfortunately I can't post it, as it is library code (not my lib). But in the debug-output I can see the SQL-String sent to the DB (which does include the hint).
But I find the 2nd option you mention more likely anyway: Even if I put the hint into a VIEW and select from the view, the time-difference is there (it's even there if I use Table Functions/Pipelined table and select from the function).
So I'd think it is more likely that something else is happening (e.g. Oracle is configured in a way that it does not use hints when called from JDBC or similar. Or the library sets some session options in order to prevent the usage of hints). But I don't know if there is even the possibility of doing so.
Does the Oracle JDBC driver have the option to set these options?
Does the Oracle DB have the option to set sth. like "ALTER SESSION SET dontUseHints = 'Y';"