andy@garfield.columbia.edu (Andy Lowry) (04/19/88)
I am looking for information and references on the following topics: 1. Effect of concurrency control on overall performance of database systems. 2. Implementation of concurrency control in ACTUAL database systems. With regard to #1, I would also welcome more generally any information on the breakdown of processing costs among the various tasks of DBMS (besides concurrency control, this might include logging and other tasks in support of recovery, query parsing and optimization, relational operations (join, projection, etc), index lookup and maintenance, etc.). With regard to #2, I'd like to find out which policies (two-phase locking, timestamp ordering, conflict graph testing, ...) are actually used, how they are implemented, what factors affected the choices, hindsight, etc. For both questions I am interested in centralized and distributed databases, and also in database machines that support concurrent queries. I have many references on proposed concurrency control policies and algorithms. What I'm interested in here is: what do things really look like in the real world? Thus commercial systems are of interest, but also working non-commercial systems. Literature references and personal knowledge are both solicited. Please e-mail directly to me, and I will summarize to the net. Thanks!! -Andy andy@cs.columbia.edu
sysop@stech.UUCP (Jan Harrington) (04/21/88)
in article <5535@columbia.edu>, andy@garfield.columbia.edu (Andy Lowry) says: > > I am looking for information and references on the following topics: > > 1. Effect of concurrency control on overall performance of > database systems. > > 2. Implementation of concurrency control in ACTUAL database > systems. A definitive work on concurrency control and recovery was published last year by Addison-Wesley. The author is Bernstein, though the exact title escapes me at the moment. It will answer your first request, perhaps in more detail than you think. As for the second, you may have to consult vendor documentation to get details. At least, that's what I've had to do (I'm in the middle of a multiuser micro DBMS concurrency control performance study) ... Jan Harrington, sysop Scholastech Telecommunications UUCP: ihnp4!husc6!amcad!stech!sysop or allegra!stech!sysop BITNET: JHARRY@BENTLEY ******************************************************************************** Miscellaneous profundity: "No matter where you go, there you are." Buckaroo Banzai ********************************************************************************