SQL Databases Are An Overapplied Solution

Re:SQL Databases Are An Overapplied Solution by lsb on Friday July 10, 2009 @02:40AM (#697216)

K/V stores don't provide ACID properties themselves, but you could bolt them on pretty easily. For instance:

Atomicity: save a journal of the pre and post values of any rows, and on commit take all of your staged changes and write them and then delete the journal. If you're ever going to hit the DB again and you see a journal file that wasn't cleaned up, roll back to whatever pre values there are.

Isolation: use a semaphore to cause the start of a writing transaction to block all reads and writes, use a semaphore to cause the start of a reading transaction to block all writes, and escalate from reading transaction to writing transaction when necessary.

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Re:SQL Databases Are An Overapplied Solution by silentbicycle on Friday July 10, 2009 @08:47AM (#697577)

Transactions are actually incredibly tricky to get right, particularly in a portable manner. Not exactly the sort of thing one can implement in a weekend.

For example: http://sqlite.org/atomiccommit.html

Also, it will slow down the database a bit (particularly if added to the db as an afterthought!), which seems to really irritate people who would rather have potentially corrupt information as soon as possible rather than automatic guarantees of internal consistency.

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Re:SQL Databases Are An Overapplied Solution by nettdata on Friday July 10, 2009 @01:00PM (#697989)

And let's not even start talking about consistent reads.

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