Custom SQL vs Dynamic SQL: is there any performance differences?

[Riya M S，修改在11 年前。]

Hi Everyone,

Just wondering: is there any significant performance difference between Custom SQL and Dynamic SQL?

Let's assume the following scenario:
- the target database is an MySQL
- the adapter will be called by a real time interface;
- the interface will be called by multiple clients concurrently - let's stick with 10 at a given moment;
- the interface needs to query the database to check if the value is valid, and return the result.

Given the following SQL (Custom SQL):

select colA, colB
from aSchema.aTable
where colA = ?
and colB = ?

and (Dynamic SQL):

select colA, colB
from ${schema}.aTable
where colA = ${paramA}
and colB = ${paramB}

and a third case (Dynamic SQL):

select colA, colB
from ${schema}.aTable
where colA = ?
and colB = ?


Analyzing just only the JDBC adapter service portion: is there any significant performance difference between Custom SQL and Dynamic SQL?

[David H Nebinger，修改在11 年前。]

This is not a Liferay question. It is more appropriate to post to the MySQL forums instead.

[Hitoshi Ozawa，修改在11 年前。]

I think what you really want to know is about caching.
Dynamic SQL is just dynamic sql in hibernate.