Is NoSQL really necessary or do we just need a better SQL?

Isola9on   Isola?on  is  specified  further  as:   •  read  uncommi6ed   •  read  commi6ed   •  repeated  reads   •  snapshot  isola?on   •  serializable   There  are  two  ways  to  implement  isola?on;  either  “locks”  or  “mvcc”.   Using  locks  it  is  hard  to  predict  the  order  in  which  transac?ons  will  gain   the  lock.  Using  mul?-­‐version  concurrency  control  a  transac?on  might   abort  or  restart,  because  it  is  going  to  write,  but  that  write  is  currently   prohibited.  In  both  cases  the  behavior  is  not  determinis?c.  As  a  side   remark  one  should  keep  in  mind  that  in  the  past  transac?ons  have   been  long-­‐runners.  That  is  to  say,  transac?ons  waited  most  of  their   ?me.  Nowadays,  transac?ons  are  very  short  lived.