not to mention, updating any field on table 2 requires the entire contents to be written out again instead of being able to effect those columns individually.
Quite a few NoSL solutions work on a similar model which, while useful in places, is decidedly NOT relational. If you are *certain* that the primary key is the only key you will ever need and it is acceptable to read/write all fields together each and every time, then perhaps one of those products will suit you. MySQL is a Relational Database Management System and best suited for relational database management. Don't take this as a specific recommendation. My experience with NoSQL systems suggests that in many cases the application would have been better off with a relational engine underneath. All too often, a lack of up-front analysis lures developers and architects into thinking that the relational properties are not important, only to find out later in the project that they are critical., - michael dykman On Tue, Feb 28, 2012 at 2:41 PM, Paul DuBois <paul.dub...@oracle.com> wrote: > > On Feb 28, 2012, at 9:59 AM, Zheng Li wrote: > >> for example >> there are 2 tables to save same data >> table A has 10 columns: a primary key column and 9 blob column >> table B has 2 columns : a primary key column and 1 blob column which >> includes all data in 2nd~10th columns of table A >> >> are there any differences in performance when selecting, inserting, >> updating, and deleting data. > > Sure. For example, with table A, you can select only those blob columns > you're interested in. With B, you have to select all of them if you want > *any* of them. > > > -- > Paul DuBois > Oracle Corporation / MySQL Documentation Team > Madison, Wisconsin, USA > www.mysql.com > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/mysql > -- - michael dykman - mdyk...@gmail.com May the Source be with you. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
