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JavaPerformanceTuning.com is not the only place where they interview people about performance (though their interviews are pretty close to the best I've seen, packed with useful and relevant info). I came across this excellent interview with Michael Widenius, one of the MySQL creators, talking about in-memory databases.
The basic premise is that RAM is now so cheap and available in such large configurations that you can store it all in memory. A multi-gigabyte database fits into RAM that costs just a few hundred dollars. The interview discusses the changes in database design that are needed to handle this mode of database operation.
But what leaped out at me was that you could take a running Java VM, and just store the data structures directly in memory rather than storing the data into a database. I mean if you are already supporting in-memory data structures, why go through conversion inefficiencies? You start your JVM, and just load a "database object" directly into the JVM with access to all the data in object structures. I guess this essentially becomes an object database rather than a relational database, and it would be immensely efficient.
I bet that in about two or three major versions, say by the 1.7 release, we will be able to specify alternate data storage locations for objects created by the JVM. Like a "short-life" memory, a "long-life" memory, a "no collect" memory and a "persistent" memory. Now that I think about it, I even seem to recall seeing a proposal along the lines of JVMs supporting multiple memory models somewhere (though I can't recall where). You specified the "current" memory and any objects created went into that currently specified memory. Yes, for sure this is coming.
You heard it here first.
July 2. Ugh, got a memo from Hilite. "Please note that the luminous sandwich in the fridge, room 232, is my property, and should not be tampered with. All bitemarks will be investigated using both dental records and DNA investigation. Taking property that is not yours is theft". The memo was, of course, hi-lited in lurid green. He must have spent days hi-liting all those memos. Everyone that I could see had one. Unbelievable.
July 9. I checked, and no one ever sees Hilite hi-liting his memos. He must take them home to do it. Hilite is uncannily close to a Dilbert character. Apparently it started when the spare wheel from his car was stolen. Someone told him that it's quite a common theft, and some people chain up their spares with a padlock, but that a few people spray paint the spare a color like shocking pink and that deters the thiefs. After all, if you are going to rip off a spare wheel, why go for the easily distinguished one when there are so many others - it usually happens in car parks. So Hilite sprayed his spare wheel, then decided it was such a good idea he started extending the idea. His shoes have wobbly green stripes on them, all his office equipment are marked, and now it seems his sandwichs are too (the wrapping, not the actual food).
July 16. Found out what Hilite uses to make his sandwich wrapping luminuous green. Interesting combination.
July 23. What a shouting match. Haven't seen one like that since Screamboy was told that his services were no longer required. Ouch, I still wince when I think of that one. His manager had to take a week off to recover and the security guards had to drag Screamboy out of the building, still shouting after four hours of continuous expletive laced graphic imagery about his boss's assumed after hours proclivities. This time it seems that Hilite's sandwich disappeared. And with the lights off in the evening luminuous green was clearly visible on Weevil's desk. Hilite was screaming at Weevil, Weevil was screaming back at Hilite, Frezian was screaming at both of them, and the rest of the floor were encouraging them all. There's no business like the I.T. business, not even show business.
Javva The Hutt.
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