Talk:ACID

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[edit] Proposal

I propose that the ACID article, being a disambiguation page, should mention both acid as in acidic chemicals, and also maybe mention that it is a nickname of LSD.

These are all fairly common uses of the word ACID, and thus should be reflected in the article.

I think that the above comment is outdated (as there is an "acid" and not "ACID" disambugation page). Someone please confirm this.

you mean "Acid", this one is about chemicals I think everything's ok as it is..

I agree with the last statement, leave it as it is. When you see uppercase letters in a dictionary or encyclopedia, it means it is an acronym and it stands for something else. I think it is in the correct context.

  • I agree. A disambiguation page should not contain detailed info on one definition.
    Most of the contents of this page should be moved to ACID (database).
—gorgan_almighty 13:24, 8 December 2005 (UTC)

[edit] Consistency

If I remember correctly the "Consistency" in ACID refers to the fact that the Database must ensure that the order of the queries must be consistent:

  • Imagine a transacction A starts on time T
  • Another unrelated query B starts at T+1
  • If the unrelated query B tries to access some of the values beign modified by the A transaction, the database will wait till the transaction to finish, and give the data modified to the B query. If fact, modern databases will run the B query, wait for A, if A affects data readed by B, rollback B and repeat that query again.
  • The result is that if B goes after A, the operations will be always the same, no mather if B was in T+1 when the trasaction A was still running or T+200. The virtual time for all the modifications that the transaction A makes is T, so any T+1 query will see that modifications in place.

The article mentions consistency as "beign compliant with the constraints of the DB". Of course it is!. Constraints of the DB are unrelated with transactions! And of course transactions could not break them!

[edit] Allocated CPU time

"... it may have used up its allocated CPU time." - This doesn't seem to make too much sense. CPU time is not allocated, it's used on demand. - intgr 05:09, 18 September 2005 (UTC)

You're assuming a computer/OS can't be designed in a way that does allocate time in that way. You can imagine a company building a renderfarm and rents out computer time that would take advantage of something like that. For a real world example, the wolfram integrator (http://integrals.wolfram.com/index.jsp) is designed to timeout if it performs an integral that takes too long. Just replace the integrator with something that uses transactions and it makes sense. TomJF 04:58, 25 December 2005 (UTC)

[edit] Disambig

I subst'd the disambig link and changed it to point directly to the disambig. Figured I should mention it here. - CorbinSimpson 18:02, 29 January 2006 (UTC)

[edit] ACID -> AID? ACD?

Hi all, I recall reading somewhere that one of the properties (atomic, consistent, isolated, durable) was implied by the others, something like "if a transaction is atomic and consistent then it must have had the appearance of being isolated". Or perhaps if it's A and I then it must appear C.
Summat like that anyway, but I never found that quote again, nor anyone saying anything similar. Can anyone clarify?
ta - jan
Water pepper (talk) 22:54, 22 April 2008 (UTC)