Re: Thanks for Rekall link! - Mailing list pgsql-general
From | Christopher Browne |
---|---|
Subject | Re: Thanks for Rekall link! |
Date | |
Msg-id | m3mzrjmvh8.fsf@knuth.cbbrowne.com Whole thread Raw |
In response to | Thanks for Rekall link! (Typing80wpm@aol.com) |
List | pgsql-general |
A long time ago, in a galaxy far, far away, Typing80wpm@aol.com wrote: > I must say one intereting thing. When I downloaded the trial version > from TheKompany, and asked it to browse a test file in PGSql which I > loaded with 250,000 rows, it started to read them, and read for a > long long time (as MSAccess does), but the seemed to get stuck, > whereas MSAccess is able to browse the entire file. I must > experiment more with the demo version from theKompany, and also with > this free version from the site you gave me. This sort of problem is characteristic of the use of "array" objects in graphical toolkits. Suppose you're populating something with 250K rows, perhaps with a dozen fields per row. In such a case, the toolkit is slinging around 3-4 million objects, and having to evaluate which of them are visible on screen at any given time. _Any_ kind of inefficiency in the library, or in the use of the library, can easily lead to rendering turning out really, really badly. The X Window system has gotten heavily criticized for speed problems, commonly with respect to how Mozilla used to work when rendering large web pages. Reality was that Mozilla was implemented (this is no longer true, by the way) atop a platform-independent library called Rogue Wave which then had a mapping to Motif (which is noted as Not Everyone's Favorite Graphics Library ;-)) which then rendered things using X. The True Problem lay somewhere in that set of layers and, since several of the layers were pretty inscrutable, it was essentially impractical to address the performance problem. Much the same thing took place with the Tcl/Tk application, "cbb" (Check Book Balancer); the Tk 'array' object got to behave increasingly badly with increasing thousands of rows. And changing one transaction near the top of an account would lead to cascading balance updates, therefore walking (linear fashion, more than likely leading to superlinear resource consumption :-() through the rest of the transactions to update every single balance... Gigahertz, Gigabytes, and upgrades may overcome that, to some degree, but it wouldn't be overly surprising if you were hitting some such unfortunate case. It might represent something fixed in a later release of Rekall; it could represent something thorny to resolve. I would really hate the notion of depending on a GUI to manage millions of objects in this manner; it is just so easy for it to go badly. -- "cbbrowne","@","gmail.com" http://linuxdatabases.info/info/nonrdbms.html Rules of the Evil Overlord #10. "I will not interrogate my enemies in the inner sanctum -- a small hotel well outside my borders will work just as well." <http://www.eviloverlord.com/>
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