@Tinkeringbell Short story: I don't remember if it was metadata, tags or whatever, but apparently you can associate something to a table in Oracle. Let's just call them "TERMS". Each terms is associated to a prime number (that you have to MANUALLY specify when you create the TERM - I remember that the article linked an offical pdf doc on Oracle servers that listed the first...... 100000 prime numbers? it was about 60-100 pages long....).
To persist what Terms were associated to which table... Oracle stored the product of the prime numbers. That is the idea presented in the link you found be…