Bitcoin is Not Just a Database in the Rasberry Pi or in the Apple Pie - Bitcoin is systemised Computational Datastructure in the Blockchain which has PoW and timestamp.

You just cannot change anything as you like to add or change aas you wish. It is cryptographically secured because it is the blockchained Database. If you alter one single indexed number, then it will alter the rest of the merkele tree and makes it unsecured.

Therefore, think not that Bitcoin Blockchain is can be altered by any one who likes to do it. It is impossible because it is the bullet proof Blockchain technology with the permanent clock base structure behind it for absolute security.