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Recently NoSQL has gained immense popularity. What are the advantages of NoSQL over traditional RDBMS?


Possible duplicate of What is NoSQL, how does it work, and what benefits does it provide?

2019年06月26日09分51秒

Could you give some examples of non-relational data?

2019年06月25日09分51秒

Documents and images can be stored inside RDBMS too like SQL Server and Oracle? Then why NoSQL?

2019年06月26日09分51秒

Semi-structured data is one such class. It contains XML, Emails, JSON, etc. See the wikipedia page on it. The general rule is that the structure is there, but is loosely defined and dynamically extensible (the latter tend to class with the relational model- and while it is not impossible to model, it is definitely cumbersome). Another class is "natural data": A Novel, An Image, both with no meta-data attached.

2019年06月25日09分51秒

Well, you can't do SELECT blob FROM images WHERE blob CONTAINS('red car'). So while you can store the data raw in the database, you can't search it without attaching metadata. Full-text-search modules in RDBMS systems bridges some of the semi-structural gap.

2019年06月25日09分51秒

duffymo: Documents are not "non relational". Documents are often stored in SQL DBMSs and you don't need a NOSQL DBMS for that. In fact NOSQL databases often use data models that are less general and more limited in application than the relational model. Eg graph databases. The type of data being stored doesn't explain any advantage of NOSQL.

2019年06月25日09分51秒

What is CAP, CP, AP, K/V?

2019年06月26日09分51秒

Look up the CAP Theorem on Wikipedia. CA and CP stems from there. K/V is short for Key/Value, a (distributed) finite mapping from keys into values.

2019年06月25日09分51秒

"Everyone else realizes what Google just did." lol. Seems like a Scottish answer to me (aka NOT CRAP).

2019年06月26日09分51秒

It's worth noting that some NoSQL databases support ACID transactions.

2019年06月25日09分51秒

It seems that at the recent O'Reilly Strata Conference, Mark Madsen has coined a new interpretation of "NoSQL" in his history of databases in no-tation to supersede "Not Only SQL". It is now: "No, SQL" ;-)

2019年06月26日09分51秒