Some thinkings and notes
IT systems mostly exist in the 'last write wins' (LWW) world. This approach has its own advantages, particularly due to its simplicity. However, that doesn't mean it is the best method in all cases. Sometimes, it's necessary to prevent data loss or to ensure that our changes are made based on the version of the data that client intended to change.
Shadow Paging is a renowned database recovery technique, an essential safeguard in the field of data management, ensuring the stability, integrity, and recovery of databases in the face of system failures or crashes. It eliminates the need for logging operations and allows for atomic transactions, making it a preferred choice for many data-heavy applications.
In most modern file systems where techniques like journaling or copy-on-write is used, the write operation of block is atomic. In Postgres documentation mentioned that there is no partial-write problem when they write pg_control, because it is smaller than one disk page.