Outer join (+) operator and version 7.8

[Former Member]

I'm using hibernate 3.3 on jboss 5.1.

This configuration uses the operator for outer joins. On MaxDB 7.7 it was working, it doesn't work in 7.8.

Is there a way to get it back in 7.8 ?

Thanks

[Former Member · Accepted solution]

Found the parameter "EnableLegacyOuterJoinSyntax" that, when set to YES, enables the operator.

[thorsten_zielke · Accepted solution]

Correct, enabling this parameter will revert to the old 'Oracle'-like outer-join syntax instead of the ANSI standard for outer joins.

Just keep in mind that this will also disable the QueryRewrite feature (which allows MaxDB to rewrite SQL statements 'on the fly' for better performance or to reduxe complexity so that the SQL can be executed at all).

So my point is: if possible, use the ANSI outer join syntax and do not set this parameter unless necessary.

Thorsten

[Former Member · Accepted solution]

Thanks, I noticed that.

Just a question. Does using the operator in 7.7 affect performances as well ?

Thank you

[thorsten_zielke · Accepted solution]

First, let me say that I do not know if you would experience any performance decrease at all - that really depends on the SQL statements. In general, 7.8 is supposed to be faster then 7.7, but yes, in certain cases (e.g. when using the '+ outer join syntax') 7.7 might have the advantage.

Up to my knowledge 7.7 was a mix of old outer join syntax and new ANSI outer join support, but that part was rewritten and improved for 7.8. The legacy outer join support was introduced when we noticed that some customers would still need the old syntax (SAP systems now use the ANSI outer join syntax) .

Thorsten