A static dataset is stored as a simple big matrix, which can take some time to load and fill up too much memory. A dynamic dataset remembers the offsets of each sample, allowing to load only one sample at the time, which is much more memory-efficient.
To convert a static dataset to dynamic, one can use this command:
dscompile /data/ -load my_static_dataset -nopp -dname my_dynamic_dataset
To convert a dynamic dataset to static, one can use this command:
dscompile /data/ -load my_dynamic_dataset -nopp -dname my_static_dataset -save dataset