speed of class loading via a modulepath

Richard Hillegas rhillegas at comcast.net
Sun Nov 18 20:00:14 UTC 2018


I am updating Apache Derby documentation to reflect the recent 
modularization of the codeline. While doing this, I have stumbled across 
an old piece of advice from the Derby Tuning Guide:

"The structure of your classpath can affect Derby startup time and the 
time required to load a particular class.

The classpath is searched linearly, so locate Derby's libraries at the 
beginning of the classpath so that they are found first. If the 
classpath first points to a directory that contains multiple files, 
booting Derby can be very slow."

That may be an old, Java 1.2 concern, which no longer affects modern 
JVMs. I have a couple questions:

1) Is this still good advice when booting a large application like Derby 
via a classpath?

2) What about the modulepath? Can classes be faulted in faster by 
re-arranging the order of jar files on the modulepath?

Thanks,
-Rick



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