I work on contract and as a consulting Oracle DBA. I've migrated several companies from SQL Server because the block level locking did not scale to Oracle. I never had anyone ask me if I could convert them from Oracle to SQL Server. ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Thursday, October 31, 2002 11:19 AM
> Disagree. > > "row-level" locking in SQL Server was introduced in some capacity only in > SQL Server 7 (not long time ago). > Before, it was "block-level" locking, and I saw lots of problems with that. > It's not the length of the single statement (select/update/...) that > matters. It's the length of the transaction, that causes a problem, if > "block_level" locking is used (and could be automatically escalated to > "extent" or even "table" level lock). > > Igor Neyman, OCP DBA > [EMAIL PROTECTED] > > > > ----- Original Message ----- > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Thursday, October 31, 2002 10:18 AM > > > > I don't see it as a gotcha, I've worked with SQL Server for almost 6 years > > on some pretty big databases and have never had a problem. > > > > At the end of the day, locking is at the row level, locks are held for a > > very short time (unless developers don't know what they are doing). A read > > will take a shared row level lock for a sub-second period of time > > (potentially), if your update is blocked for 0.2 seconds are you going to > > notice ? You have to realise that with row level locking the scope for > > blocking is minimal. > > > > Ade > > > > -----Original Message----- > > Sent: 31 October 2002 14:04 > > To: Multiple recipients of list ORACLE-L > > > > > > > > But this default mssql behaviour is the performance 'gotcha' where readers > > block writers and writers block readers isn't it? > > > > > > Mike. > > > > -----Original Message----- > > Sent: 31 October 2002 09:12 > > To: Multiple recipients of list ORACLE-L > > > > > > 'Dirty reads' in SQL Server means that you can view records that have not > > been committed. This is implemented by setting the TRANSACTION ISOLATION > > LEVEL to READ UNCOMMITTED. > > > > This is not default behaviour in SQL Server, the default TIL is READ > > COMMITTED (for very good reason). I can think of very few situations where > > you would want to see uncommitted records. > > > > Dirty blocks in SQL Server/Oracle are the same thing ie. a block/page in > > cache that has been changed but not flushed to disk. > > > > Ade > > > > -----Original Message----- > > Sent: 30 October 2002 18:43 > > To: Multiple recipients of list ORACLE-L > > > > > > It sounds like he is saying that, once an "insert, update or delete" > > statement has been issued (without a following commit), then the records > > acted upon are now considered "dirty" - i.e. needing writing to disk. > > > > this is, of course, NOT what Oracle considers a dirty block. > > > > I agree with you, Jared! > > > > Tom Mercadante > > Oracle Certified Professional > > > > > > -----Original Message----- > > Sent: Wednesday, October 30, 2002 1:21 PM > > To: Multiple recipients of list ORACLE-L > > > > > > At least one of us has the incorrect understanding of 'dirty' reads, > > or I am taking you too literally, or something. > > > > What are you really saying? > > > > Oracle does not allow dirty reads. > > > > All queries are consistent to a point in time, the beginning > > of a transaction, whether implicit (select) or explicit ( start > > transaction ). > > > > SQL Server and Sybase do not guarantee this. > > > > The 'dirty' reads you are speaking of sound more to me > > like sloppy programming. > > > > Is that what you're referring to? > > > > Jared > > > > > > > > > > > > > > "Yechiel Adar" <[EMAIL PROTECTED]> > > Sent by: [EMAIL PROTECTED] > > 10/30/2002 08:54 AM > > Please respond to ORACLE-L > > > > > > To: Multiple recipients of list ORACLE-L > <[EMAIL PROTECTED]> > > cc: > > Subject: Re: RE: oracle or mssql > > > > > > I would like to point out that what you call "dirty reads" are mostly > > the correct reads. Oracle method IS the dirty read. > > > > I am sure that your users does at least 1000 commits to every rollback. > > So when oracle gives you the data it already knows that this data is > > wrong. If you do the query again a minute later you will get new results > > that were available when you did the original query but were committed > > later. So you get a 1000/1 chance to get incorrect data. > > > > The "dirty read" method, on the other hand, gives you the current values, > > believing that they will be committed in a moment. So you get 1/1000 > > chance > > to get wrong data. > > > > Which odds will you bet on? > > > > Yechiel Adar > > Mehish > > ----- Original Message ----- > > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > > Sent: Tuesday, October 29, 2002 2:18 PM > > > > > > List, > > I'm always keen to refresh on database comparisons so thanks for > > everyone's pointers. > > > > I'm surprised Oracle doesn't make more of an issue about their locking and > > concurrency methods (i.e. redo/rollback/undo). > > > > MSSQL seems to deal with it in two ways: > > Default: readers and writers prevent writers from accessing data until > > they > > are finished with it! > > Other method: no control, you just get dirty reads! > > > > Anyone got anything to add to this? Or am I wrong? > > > > - Mike. > > > > > > -----Original Message----- > > Sent: 24 October 2002 17:29 > > To: Multiple recipients of list ORACLE-L > > > > > > As I said, use mssql ONLY if your boss is willing to be strapped into a > > MicroSlop only platform. If he's even remotely thinking of using a > > different OS > > then you can't use mssql. > > > > Dick Goulet > > > > ____________________Reply Separator____________________ > > Author: [EMAIL PROTECTED] > > Date: 10/23/2002 11:48 PM > > > > goodmorning > > everybody who responded to my basic question : thanks > > > > summary > > > > professional : use oracle enterprise edition > > semi professional : use oracle standard edition / mssql enterprise edition > > in all other cases mssql standard edition > > > > > > > > > -----Oorspronkelijk bericht----- > > > Van: Mohammad Rafiq [SMTP:[EMAIL PROTECTED]] > > > Verzonden: woensdag 23 oktober 2002 20:51 > > > Aan: Multiple recipients of list ORACLE-L > > > Onderwerp: RE: oracle or mssql > > > > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > -- > > Author: Jenner Mike > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > > > -------------------------------------------------------------------------- > ---- > > Live Life in Broadband > > www.telewest.co.uk > > > > > > The information transmitted is intended only for the person or entity to > which it is addressed and may contain confidential and/or privileged > material. > > Statements and opinions expressed in this e-mail may not represent those > of the company. Any review, retransmission, dissemination or other use of, > or taking of any action in reliance upon, this information by persons or > entities other than the intended recipient is prohibited. If you received > this in error, please contact the sender immediately and delete the material > from any computer. > > > > > > > ============================================================================ > == > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > -- > > Author: Adrian Roe > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Igor Neyman > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Tom Pall INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
