RLL, PLL, and TPC-C: A Useless Thread

Pablo Sanchez (pablo@sgi.com) wrote: > David> if page was faster Informix would use > David> page level locking in TPC tests!! > > Right, sorta. I don't have the FDR for Informix on which > tables were and were not using page level locks. What the > bench points to is that with Sybase, doing PLL, it can (and > does) perform as well (and this instance better) than an > RDBMS that has the ability to do RLL. > Which proves precisely nothing - unless you're claiming that the 60% performance boost you've been referring to rests solely on Sybase's lack of PLL. If so, this is as unscientific a claim as you can make. TPC-C measures *overall transaction performance* - it does not isolate specific RDBMS features or components. One might as well (arbitrarily) say that Informix's SQL optimizer (or raw disk access routines, or implementation of stored procedures, or table storage format, or request dispatcher) is less efficient than Sybase's because Sybase has a better tpmC. Unless you can demonstrate that, **ceteris paribus**, RLL is slower or not much faster than PLL, pointing to the TPC-C benchmark means nothing. While it'd be interesting to read the Full Disclosure Report for the Informix tests and see how much RLL was employed vs. PLL, that information - just like Informix's general tpmC ratings - will tell us nothing about RLL vs. PLL. If you can show PLL performs as well or better than RLL on two different instances of the same Informix database with the same Informix engine on the same hardware configuration, with one DB tuned for RLL and the other not, then I'll be listening. If you can compare a PLL-only system with an RLL-capable system, show that RLL is used, *and* show that your numbers isolate PLL vs. RLL performance, I'll be eager to see them (and to hear how the hell you pulled it off, considering the number of other possible factors involved). Otherwise, please be merciful and kill this useless thread. -J- -- Jay Allen Senior Applications Developer Auragen Communications, Inc.