Maybe you have misconception about the scalability of PostgreSQL.
> According to Instagram representatives, the number of platform users exceeded 2 billion last year. This is quarter of all humanity. This mass of people publishes nearly 50 million photos a day. Football star Cristiano Ronaldo has over 600 million followers; singer Ariana Grande has over 380 million. Talk about huge databases!
> Instagram uses many RDBMSs, but PostgreSQL and Cassandra were chosen for the main tasks. The goal was to reduce delay and ensure users can easily and comfortably use the application.
PostgreSQL is also the most popular database in StackOverflow surveys.
"popular with developers" is not the same as actually used in real world scenarios. Show me a real world example of pgsql failover and re-mastering that does not involve a restore and not editing configs. How basic? Not even sybase ASE server needs that. Ingres made change in the 80's, everyone else copied it and built on it. Except postgres. It's the Minix of databases.
Show me any proof, that anything of scale is happening in postgresql. All that big facebook and apple data is happening in cassandra (and foundationdb for apple).
Netflix has the same pattern, MySQL and Cassandra. Like the days of yore of keeping big data in file systems or tapes and blob indexes in a RDBMS.
> All that big facebook and apple data is happening in cassandra (and foundationdb for apple)
Not sure about Instagram, but I can tell you with complete confidence that Facebook proper (meaning specifically Facebook, not the rest of Meta) moved away from Cassandra well over a decade ago. They originally used Cassandra for FB messages / Messenger, but soon migrated to HBase and then over to MySQL / MyRocks.
> According to Instagram representatives, the number of platform users exceeded 2 billion last year. This is quarter of all humanity. This mass of people publishes nearly 50 million photos a day. Football star Cristiano Ronaldo has over 600 million followers; singer Ariana Grande has over 380 million. Talk about huge databases!
> Instagram uses many RDBMSs, but PostgreSQL and Cassandra were chosen for the main tasks. The goal was to reduce delay and ensure users can easily and comfortably use the application.
PostgreSQL is also the most popular database in StackOverflow surveys.