we are working on huge project wit flex+java+hibernate. we use eclipse default builder to build the project ,which take hell lot of time and some time we see out of memroy error too.what can we do ?? and build script will help us or what else?Also even after changing a single label in mxml file we need to build the application again ? whats the alternative?
There is no alternative. MXMLC seems to be fairly poorly designed when it comes to how it works out what needs recompiled. I see the same behaviour, a small change and MXMLC touches what looks like all files in the project. You can work round the memory issues - just give eclipse more heap space to use. We found a MXMLC does use multiple CPUs well so a multi-core PC helps (though its still got to do all that IO to work out what needs built).
Its worth mentioning that with Flash very large SWFs are frowned upon, since the user has to download a single large file. you might consider breaking your application up into distinct components you load on demand. Better for the user and it might mitigate your build problems.