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

>>>>> "David" == David Williams <djw@smooth1.demon.co.uk> writes: David> David> Imagine 1 page with 2 rows one it. David> David> 1. Page level locking David> David> User A updates row 1 David> At the same time user B updates row 2. User B has to wait for David> User B to commit. David> David> 2. With row level locking David> User A updates row 1 David> User B updates row 2 (with no waiting). David> David> How can 1 be faster than 2 if user B has to wait? You're forgetting the RDBMS's latency to acquire and release locks for the rows. It all adds up and offsets the gain. You can't just look at a small piece of *anything*. You have to, pardon my Boulderism, look at the problem holistically. >> If you look at the TPC-C's (as I've mentioned, before) >> you'll see another highly tuned (OLTP) application. If I >> compare the *currently* submitted numbers for Sybase >> vs Informix I see the following: >> >> Sybase..... 39,469 tpmC >> Informix... 24,309 tpmC >> >> That's a 62% performance increase by using Sybase. Now I >> grant you that I believe that we'll see Informix >> Inc. publishing even higher numbers but that's not my >> point. My point is: >> David> I checked the results, these figure come from different machines. David> So Sybase runs their TPC benchmarks on larger hardware..so? If your first example had validity, then your above statement wouldn't matter. A faster machine would mean that you'd get to the wait that much faster, but that's not what is happening. We're seeing that Sybase is scaling with the hardware provided. You buy a bigger machine to get more throughput... >> For a finely tuned application, row level locking >> does *not* matter. David> Lock granularity is still a problem. Why do UNIX kernels lock David> individual files and data structures rather than having one large David> kernel lock? We're not talking database locks versus page level/row level. We're talking page level and row level. There lies the difference. -- Pablo Sanchez | Ph # (650) 933.3812 Fax # (650) 933.2821 pablo@sgi.com | Pg # (800) 930.5635 -or- pablo_p@pager.sgi.com ------------------------------------------------------------------------------- I am accountable for my actions. http://reality.sgi.com/pablo [ /Sybase_FAQ ]