Hi I am j2ee developer ,i have worked with Oracle and MySQL, I liked Derby and have been using it for prototyping my j2ee applications.
I am thinking to use the same for a job portal where data volume and application load will be relatively more when compared to simple web applications.
I have some quick questions..

can it be used for big enterprise applications?
does data access and write operations gets slow down as volume of data increases over time?
is there any limitations of derby...?