专家对 MapReduce 批评的要点

原文来自：
DeWitt和Stonebraker对MapReduce的批评
我客观的记录一下其中的要点，以分享，如下：

4.  MapReduce is missing features

All of the following features are routinely provided by modern DBMSs, and all are missing from MapReduce:

    * Bulk loader — to transform input data in files into a desired format and load it into a DBMS
    * Indexing — as noted above
    * Updates — to change the data in the data base
    * Transactions — to support parallel update and recovery from failures during update
    * Integrity constraints — to help keep garbage out of the data base
    * Referential integrity — again, to help keep garbage out of the data base
    * Views — so the schema can change without having to rewrite the application program

In summary, MapReduce provides only a sliver of the functionality found in modern DBMSs.