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Alternatives to SQL DatabasesAlternatives to SQL DatabasesPosted Apr 20, 2009 18:22 UTC (Mon) by rfunk (subscriber, #4054)In reply to: Alternatives to SQL Databases by dmag Parent article: Alternatives to SQL Databases I may not have been clear. I'm not looking for a general explanation of ACID; I know what it is. I'm looking for specifically how each of these doesn't fit ACID.
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Alternatives to SQL Databases Posted Apr 22, 2009 2:31 UTC (Wed) by dlang (✭ supporter ✭, #313) [Link]
I agree that this is a huge gap in this article.
after the first two paragraphs it ignores the issue it raises to become just a list of random datastores
to make a reasonable decision we need to know what the trade-offs are of each option
for example
memcached fails ACID because it stores everything in ram, so it looses the D (durability)
note that many 'regular' databases can also be configured to sacrafice durability in the name of performance.
the real common thread between these datastores is less the fact that they sacrafice ACID than in the fact that they ignore SQL.
Alternatives to SQL Databases Posted Apr 22, 2009 12:49 UTC (Wed) by dmag (subscriber, #17775) [Link]
> the real common thread between these datastores is less the fact that they sacrafice ACID than in the fact that they ignore SQL.
Yes and no. The reason they don't have SQL is that they are young and focused on being different than RDBMSes.
It's actually not that hard to add some SQL support. Amazon's SimpleDB recently added "SQL-like" querying (nothing fancy, just "Select * from Table Where Field=Value"). There are a lot of SQL parsers out there, so it wouldn't be too hard for the others to add a large dose of SQL. Mind you, I don't think any of these will be 100% fully SQL-compliant. But then again, just about every RDBMS ignore some of the dark corners of the SQL standard anyway.
The reason for this new generation is that they scale better on one box, and scale better on multiple boxes. There's a reason that Amazon, Google, Yahoo, etc aren't "powered by Oracle" at their heart.
Each makes completely different assumptions about data. For example, if you are OK with "eventually consistent", you can have better availability during a network partition event.
I think their biggest win will be performance. All of these projects are too young to be fully tuned, but "Real" databases have a lot of overhead logic (query parser, query optimizer, transaction subsystem) that could be tossed out if you want 'bare metal' performance. For example, storing your Order + all its LineItems together means less I/O. Even if you tell your RDBMS to write to memory, I'll bet it's doing all kinds of layout tricks to optimize the "disk".
Alternatives to SQL Databases Posted Apr 22, 2009 23:03 UTC (Wed) by nix (subscriber, #2304) [Link]
I've seen one site that I know for sure is 'powered by Oracle': Oracle's
own Metalink site. Its performance is utterly appalling: half-minute delays between doing anything and the response... Oracle's stunning (lack of) useful full-text search capabilities shine through in the completely hopeless search page as well. Of course I don't know what systems back this site but I doubt it's exactly underpowered.
For a long time they had their advertising slogan 'Oracle Software Powers
Oracle is quite good at massive thumping bank systems, but I wouldn't back
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