What was the motivation to move to Map Reduce in the first place if a well understood technology, MySQL, works fine?
(sorry if I am posting a lot on this topic. I am really interested in finding answers rather than trying to prove any point that relational databases are better in case anyone thinks otherwise).
(Poster) we moved from mysql+innodb/myisam to hadoop because of performance problems. We did test and evaluate hadoop, and then jumped. Then tokudb comes along (technically we moved back to mariadb) and puts performance advantage firmly back on mysql's side. I imagine impala and presto and any other column based, non-map-reduce engines would give tokudb a fairer fight though.
What was the motivation to move to Map Reduce in the first place if a well understood technology, MySQL, works fine?
(sorry if I am posting a lot on this topic. I am really interested in finding answers rather than trying to prove any point that relational databases are better in case anyone thinks otherwise).