Re: Informix vs. Sybase vs. Oracle vs. (gasp) MS SQL Server

In article <3482318D.C4112DA5@voicenet.com>, "Scott C. Gray" <ickyspam_gray@voicenet.com> writes >David Williams wrote: >> >> In article <3481D92B.75AA9F0D@voicenet.com>, "Scott C. Gray" >> <ickyspam_gray@voicenet.com> writes >> >> page level locks give HIGHER PERFORMANCE yes BItUT the reduce >> >> concurrency and hence LOWER RELIABILITY. >> > >> >Be careful with your wording...locking granularity has nothing at >> >all to do with reliability (indeed, table locking vs. column locking >> >has the same reliability when properly implemented). It is all >> >simply a matter of concurrency and efficiency. >> >> Most applications produce an error when a lock error occurs. >> > >I assume that you are referring to deadlocks. While it is true that >deadlocks may be reduced in a row vs. page locking environment, they >can still occur (don't forget we are only talking about locking... >not versioning--which can also be done in a page locked environment). > >It is foolish for any application developer to fail to check for such >conditions (although, in my experience, almost everyone does). >Thus, for a properly coded application, page locking does not >reduce application reliability one bit...it just increases the >likely hood that the proper error detection/recovery code will >be executed (although, in a properly developed environment, it >is possible to eliminate deadlocks anyway). > Correct, the user will receive an error message saying this item cannot be updated an hence this "the application failed with an error, it is not as reliable as other applications". >> 1. Queries fails >> 2. Database modifications produce an error and the transaction is >> rolled back (few applications retry). >> >> Hence APPLICATION RELIABLITIY is reduce. > >Once again...be careful about your wording. It seems that you >are producing a false analogy along the lines of: > > 1. Some conditions cause the database to generate an > error. > 2. Many applications don't check for these errors > > The database is not working properly. > No, but I'm syaing the user sees more error messages and updates which failed to complete. -- David Williams