“It is like viewing a text file”. This is an analogy.
If I type
less mycoolfile (completely separate from any aspect of SciDB). The file in this case is the text file “mycoolfile”. When I type
less mycoolfile, the text file,
mycoolfile, remains on the disk. The contents of the text file,
mycoolfile, is read into main memory and then is displayed to the terminal. The bits on the disk that make up
mycoolfile are not changed. They are merely copied into main memory so they can be displayed.
There are not two different binary patterns (versions). This is fairly standard computer architecture: disk -> main memory -> cpu cache --> register.
Why do you say this? That is simply not true. The different forms are “one maintained by CMOS transistors in main memory” and the the other as “North-south magnetic polarization sections on a magnetic media”(assuming standard HDD).
(Minor caveat… with one possible exception of using compression. In that case, the data in memory is compressed before writing to disk and the uncompressed form would remain in main memory.).
As an EXAMPLE:
Say you are using an Office Product like “Word” or “LibreOffice”. And you start writing a document. When you “save the file” the “bits in main memory are written to disk” but they remain in main memory so that you can continue to edit the file. In fact in DocX and ODT formats, the XML which is in main memory is compressed into a “blob” that is stored on disk. When you open a “docx” file, Microsoft Word will “decompress the ‘blob’ in the file” and store the uncompressed bits in main memory.