|
|
Sponsored Content
Special Forums
News, Links, Events and Announcements
Complex Event Processing RSS News
DEBS08(3) - Continuous Queries
Post 302211607 by Linux Bot on Friday 4th of July 2008 12:10:10 AM
07-04-2008
DEBS08(3) - Continuous Queries
vincent
Thu, 03 Jul 2008 17:19:31 +0000
Next from the Distributed Event Based Systems conference: the CQL tutorial by Dieter Gawlick and Shailendra Mishra, covering Oracle’s version of a continuous query language [*1]. What was interesting was their defense of the claim that “your database server can do your CEP” [*2], supposedly reinforced by the observation that “you get all the (usual) DB management functions for free” [*3]. The traditional 3-tier, database-persistence-as-a-core-service, architectural design pattern is of course perfectly fine for, er, moderate-to-high latency projects with stovepipe services requiring minimal changes over their lifetime. Indeed, many current CEP applications augment, rather than replace, such existing architectures. But presumably you also have to consider run-time performance effects [*4] on your operational data store. Also some CQL examples display impressive contempt for the KISS principle - being of such complexity that they will undoubtedly frighten small children as well as experienced DBAs. Maybe Oracle will plan some nifty design tool for their CQL implementation, and if so, this would surely be a good topic for some future DEBS conference…
Of course, “real” ESP and CEP engines also support continuous queries - TIBCO BusinessEvents included; hence at least one answer to Hans Gilde’s recently asked question on why rule-based (monitoring) systems do not include some SQL-based Event Processing Language* is: actually some already do).
Notes.
[1] Probably, at some point, EPTS will need to publish a comparison of all the different CQL implementations and their semantics. After that, we can discuss”standardization”…* one gets the impression that Oracle would prefer to claim that their implementation *is* the de facto standard, but unlike their SQL implementation they likely don’t have anywhere near the installed base for CQL to justify such a claim.
[2] Note that a continuous query is not the same as CEP. A continuous query running against a high-latency database, for example, may just buy you a more efficient trigger representation.
[3] Presumably, not literally…
[4] I saw these cartoons in a blog recently and thought their similarity to CQL / database issues to good to pass up!
Source...
Thu, 03 Jul 2008 17:19:31 +0000
Next from the Distributed Event Based Systems conference: the CQL tutorial by Dieter Gawlick and Shailendra Mishra, covering Oracle’s version of a continuous query language [*1]. What was interesting was their defense of the claim that “your database server can do your CEP” [*2], supposedly reinforced by the observation that “you get all the (usual) DB management functions for free” [*3]. The traditional 3-tier, database-persistence-as-a-core-service, architectural design pattern is of course perfectly fine for, er, moderate-to-high latency projects with stovepipe services requiring minimal changes over their lifetime. Indeed, many current CEP applications augment, rather than replace, such existing architectures. But presumably you also have to consider run-time performance effects [*4] on your operational data store. Also some CQL examples display impressive contempt for the KISS principle - being of such complexity that they will undoubtedly frighten small children as well as experienced DBAs. Maybe Oracle will plan some nifty design tool for their CQL implementation, and if so, this would surely be a good topic for some future DEBS conference…
Of course, “real” ESP and CEP engines also support continuous queries - TIBCO BusinessEvents included; hence at least one answer to Hans Gilde’s recently asked question on why rule-based (monitoring) systems do not include some SQL-based Event Processing Language* is: actually some already do).
Notes.
[1] Probably, at some point, EPTS will need to publish a comparison of all the different CQL implementations and their semantics. After that, we can discuss”standardization”…* one gets the impression that Oracle would prefer to claim that their implementation *is* the de facto standard, but unlike their SQL implementation they likely don’t have anywhere near the installed base for CQL to justify such a claim.
[2] Note that a continuous query is not the same as CEP. A continuous query running against a high-latency database, for example, may just buy you a more efficient trigger representation.
[3] Presumably, not literally…
[4] I saw these cartoons in a blog recently and thought their similarity to CQL / database issues to good to pass up!
Source...
|
|
4 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I have a requirement like this...
I want to go to a particular server for which i have acess .I want to do a ssh to that server from one server and check if a file is theer or not..and i need the script to chcek continuosly till it finds the file.When it finds the file i want it to come out... (9 Replies)
Discussion started by: kanta_bhakti
9 Replies
2. Shell Programming and Scripting
Hi all,
I have a file like this I want to extract only those regions which are big and continous
chr1 3280000 3440000
chr1 3440000 3920000
chr1 3600000 3920000 # region coming within the 3440000 3920000. so i don't want it to be printed in output
chr1 3920000 4800000
chr1 ... (2 Replies)
Discussion started by: amrutha_sastry
2 Replies
3. Shell Programming and Scripting
Hello Folks,
Looking for a script, where i can check for the existing of the files in a directory and copying to another.
How can i achieve it in loop for over period of time.
whatever files comes into the folder copied in another without duplicate and should be continuous loop.
... (8 Replies)
Discussion started by: sadique.manzar
8 Replies
4. UNIX for Beginners Questions & Answers
Hi All,
Please help
*****************
a=100 and run for loop that will minus 30 from 100 an will display value
run loop will run till display value will be 0
*****************
Thanking you (1 Reply)
Discussion started by: Praful Pednekar
1 Replies
LEARN ABOUT PLAN9
httppower
httppower(8) powerman httppower(8) NAME
httppower - communicate with HTTP based power distribution units SYNOPSIS
httppower [--url URL] DESCRIPTION
httppower is a helper program for powerman which enables it to communicate with HTTP based power distribution units. It is run interac- tively by the powerman daemon. OPTIONS
-u, --url URL Set the base URL. INTERACTIVE COMMANDS
The following commands are accepted at the httppower> prompt: auth user:pass Authenticate to the base URL with specified user and password, using ``basic'' HTTP authentication which sends the user and password over the network in plain text. seturl URL Set the base URL. Overrides the command line option. get [URL-suffix] Send an HTTP GET to the base URL with the optional URL-suffix appended. post [URL-suffix] key=val[&key=val]... Send an HTTP POST to the base URL with the optional URL-suffix appended, and key-value pairs as argument. FILES
/usr/sbin/httppower /etc/powerman/powerman.conf ORIGIN
PowerMan was originally developed by Andrew Uselton on LLNL's Linux clusters. This software is open source and distributed under the terms of the GNU GPL. SEE ALSO
powerman(1), powermand(8), httppower(8), plmpower(8), vpcd(8), powerman.conf(5), powerman.dev(5), powerman-devices(7). http://sourceforge.net/projects/powerman powerman-2.3.5 2009-02-09 httppower(8)