Re: java stored procedures fast, but slow when called as SQL function

On 2003-04-09 13:47, pete_at_mynix.org <pete_at_mynix.org> wrote:
> Galen Boyer <galenboyer_at_hotpop.com> writes:
>

>> On 08 Apr 2003, pete_at_mynix.org wrote:
>> 
>> > The only problem, as I think I have measured, is the binding between
>> > the SQL engine and PL/SQL.
>> 
>> But Java's datatypes are java's datatypes.  What you are saying is that
>> Oracle should rewrite the internals of its storage structure so there
>> won't be any need for a conversion to java's datatypes.  It can tightly
>> couple PL/SQL with SQL cause they are both Oracle's.

Right. But those that do exist in both are most likely identical.

> 2. SQL's datatypes such as number(5,3), varchar2(20), nested tables
> etc have generic Java mappings, which are not as good a match as
> PL/SQL's. However, Oracls JDBC drivers already provide alternative
> mappings to own types; in package oracle.sql.* we have types such
> as STRUCT, REF, BLOB, NUMBER etc.
>
> Since Oracle claims it wrote the JDK basic classes (I assume this
> should include the Oracle specific JDBC classes/types as well) in
> native code, I do not see why they should not be able to get the same
> level of coupling between Java and SQL.

They might even be able to get these datatypes as fast as they are in PL/SQL, but

• They would probably be slower than the native Java types (an Oracle NUMBER is 38 decimal digits, a Java double is 64 bits, for example)
• Java programmers wouldn't use them (maybe in interface methods, but certainly not in any code which is supposed to be general purpose)

so the conversion problem still exists. PL/SQL strings can be in all kinds of encodings, a Java String is always UCS-2, so whenever a PL/SQL passes a string to Java or vice versa it has to be converted. I don't know if that is your problem, but I find it plausible that string conversion can be noticable on a java function which does nothing but return a duplicate of its string argument.

        hp

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