How much disk space can I save?
Simply execute the following statement to have a look at how much space your tablespaces currently occupy and how much space you could save. The statement provides you with the current size of each tablespace as well as the size you could shrink it to and the space you would save when shrinking it to that size:
select file_name, ceil( (nvl(hwm,1)*8192)/1024/1024 ) SHRINK_TO, ceil( blocks*8192/1024/1024) CURRENT_SIZE, ceil( blocks*8192/1024/1024) - ceil( (nvl(hwm,1)*8192)/1024/1024 ) SAVINGS from dba_data_files a, ( select file_id, max(block_id+blocks-1) hwm from dba_extents group by file_id ) b where a.file_id = b.file_id(+)
Save the space!
Then run the following statement to shrink a tablespace to a specified size.
alter database datafile '/path/to/data/file.dbf' resize 100m;
I found this very helpful hint at stackexchange: http://dba.stackexchange.com/questions/23822/how-do-we-free-up-disk-space-from-allocated-namespace-ora-03297
Create ECLIPSE_HOME system property
First, create the system property ECLIPSE_HOME, pointing to the folder in which you have your eclipse version of choice installed. If you need more that one eclipse installation, simply create multiple system properties with different names. You can also skip this step completely but it makes the shortcuts we create later more robust.
Create JAVA_HOME system property
The JAVA_HOME system property should already be set on most systems. However, you should check that it points to a JDK and not to a JRE.
Create a shortcut for each workspace
Now, create a shortcut for each of your workspaces that you want to quick access for. In windows, create a .bat file in each workspace folder with the following content (in unix systems this can be created analogous):
"%ECLIPSE_HOME%\eclipse.exe" -vm "%JAVA_HOME%\bin" -data .
This shortcut will start the eclipse installed in ECLIPSE_HOME with the Java runtime lying in JAVA_HOME. Eclipse will start with the current folder (“.”) as workspace.
Having a quick access shortcut to each workspace like above saves some time switching between workspaces. You can play around with the eclipse command line parameters and add some more or change them. More command line parameters of eclipse can be found here.