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by continuations 4622 days ago
> Having a schemaless, easy to manage database is a step forward for sooo many use cases

Can you explain why can't you do schemaless with an RDBMS?

From what I understand MongoDB is schemaless by storing all fields as one single JSON document. So what stops you from doing the same in an RDBMS - have a catch-all field "JSON" and store all your data there?
2 comments
aaronem 4622 days ago
That gets you halfway there, but you still don't have the ability to query your datastore by structure, unless you've installed PostgreSQL 9.3 and are using its JSON field type, which does have that capability, thus entirely demolishing the NoSQL USP as far as I can determine.
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edraferi 4622 days ago
That is awesome.
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aaronem 4621 days ago
Also of note is that stored procedures are supported in a variety of languages, including Javascript, so it's quite easy to handle cases where the surprisingly broad range of core JSON functions and operators [1] doesn't include what you need.

PostgreSQL has also recently added a key-value store type [2] with semantics reminiscent of Redis. The impression I get is that they're gunning for the NoSQL kids in general, and this pleases me; while I grant it is sometimes possible and necessary to obtain new insight in a field by ignoring all that's gone before, I very much doubt this is one of those times, and I am therefore delighted to see a properly engineered database engine gain more or less the entirety of the features which draw interest to the NoSQL crowd in the first place.

[1] http://www.postgresql.org/docs/9.3/static/functions-json.htm... [2] http://www.postgresql.org/docs/9.3/static/hstore.html

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chris_wot 4621 days ago
That is extremely interesting. So it looks like you can store a JSON type as well as a KV datatype in Postgres! And it looks like it is relatively easy to convert between the two.

This leaves only performance. I think I'm still confused around this area - why do people say that non-relational technologies like MongoDB are faster than relational databases?

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Goopplesoft 4622 days ago
That'd be an unqueryable string field in most sql databases. Not at all the same thing.
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