| Subject | Re: [Firebird-Java] Re: Performance bug located and solved |
|---|---|
| Author | Blas Rodriguez Somoza |
| Post date | 2002-11-23T00:39:49Z |
Hello Roman
First at all, Interclient uses also a default charset not NONE but ISO8859_1, this the reason why I do that.
Perhaps if you can tell me which problems, I can analyze it. I think the performance difference justify some work.
About the way to get the defaultCharacterSet of the JVM, Sun recomends as the only valid method the one you can see in the
getDefaultJavaEncoding method in FBConnectionHelper class. They mention that no other method can be used in all the platforms.
http://developer.java.sun.com/developer/qow/archive/55/
with the dialect, or the protocol. The server only validates is the request was wrong or not. The characterSet the client send to
the server are used for
- Communicate to the server which characterSet it receives, if the server don't know that, it seems it verify the charset.
- Request from the server which characterset wants in the data sended from the server to the client.
According to the code (jrd.cpp) this option is only available since Interbase 4.x.
set is the same as the Java defaultCharacterSet, of course this is only valid for a server for which all the default character sets
of the clients are the same.
Best Regards
Blas Rodriguez Somoza.
First at all, Interclient uses also a default charset not NONE but ISO8859_1, this the reason why I do that.
>> In inserts of character data this means a performanceI will post a question to the devel list immediately.
>> penalty of about 10% and 20%.
>Can you discuss thin in firebird-devel list?
>Of course if we find an error I can't solve, I will rollback the change, but let me try to solve the problems if they come.
> We had this issue before. There were a code when lc_ctype was
> determined from "file.encoding" property and there were a lot of
> problems with it. I strongly recommend "NONE".
>
Perhaps if you can tell me which problems, I can analyze it. I think the performance difference justify some work.
About the way to get the defaultCharacterSet of the JVM, Sun recomends as the only valid method the one you can see in the
getDefaultJavaEncoding method in FBConnectionHelper class. They mention that no other method can be used in all the platforms.
http://developer.java.sun.com/developer/qow/archive/55/
>In the remote protocol of firebird, if I'm not wrong, is the client who decide which character set to use, the same that happens
> Sorry, JayBird is a client software, this means that server determines
> what and how driver sends to server and not vice versa.
>
with the dialect, or the protocol. The server only validates is the request was wrong or not. The characterSet the client send to
the server are used for
- Communicate to the server which characterSet it receives, if the server don't know that, it seems it verify the charset.
- Request from the server which characterset wants in the data sended from the server to the client.
According to the code (jrd.cpp) this option is only available since Interbase 4.x.
> > For windows systems the charset of the database must be setWhen you create a database you define the defaultCharset. The best performance will be obtained if the database default character
> > to WIN1252.
>
> Can you explain this? Why do we enforce charset of the database?
>
set is the same as the Java defaultCharacterSet, of course this is only valid for a server for which all the default character sets
of the clients are the same.
Best Regards
Blas Rodriguez Somoza.