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This is a fairly common technique. Most banks offer similar setups.
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Nish Sivakumar wrote: The entire database is cached in-memory. The entire thing.
Calm down, it's virtual memory.
THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?!
-- C++ FQA Lite
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Sounds like physical memory to me:
>> With their SQL Servers loaded with 384 GB of RAM and 2TB of SSD...
Or is there another definition of virtual memory in DB land I'm unaware of?
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Yes, it is. I was kidding.
THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?!
-- C++ FQA Lite
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Sorry - I couldn't make sense of the contradiction even with your 'awe shucks', and it left me puzzled.
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CPallini has always told us that he's Italy's funniest programmer. The rest of us have yet to see any truth in that.
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Evidently he is a very brave man, having boldly gone a level of indirection deeper into humor then any of his countrymen. A giant in his shoes - I stand corrected. Thank you.
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Nish Sivakumar wrote: CPallini has always told us that he's Italy's funniest programmer.
They held a contest?
A positive attitude may not solve every problem, but it will annoy enough people to be worth the effort.
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Nish Sivakumar wrote: The entire database is cached in-memory. The entire thing
Yep - in fact there are database systems that are designed to work in that mode. I am working on one: SAP HANA[^]
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That sounds neat. So these in-memory databases, they would keep persisting to a more solid storage source periodically, correct?
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I would assume so. Back many years ago, I worked on some VAX/VMS systems where we had files mapped to memory for performance. Periodically, they would be 'flushed' back to the drives.
It wasn't as robust as a database system, but the concept was the same. The systems we used were integrated and could recover from a unexpected outage where data was lost.
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SQL server added optimized in memory tables for SQL 2014. SQL server ends up generating C code, and then fires up a compiler behind the scenes to generate the access and indexing code. That's probably a step beyond what stack overflow is doing, but the performance improvement can be huge, especially switching from disk optimized data structures like b-trees to hash tables. It's not necessarily about the storage, but the optimizations you can do knowing that you never have to hit disk for a lookup.
edit, added a link: http://msdn.microsoft.com/en-us/library/dn133165.aspx[^]
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Cool - interesting stuff there!
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Nish Sivakumar wrote: So these in-memory databases, they would keep persisting to a more solid storage
source periodically, correct?
Correct. Here is the architecture of SAP HANA[^] and you can see the Persistence layer which is responsible for (re)storing data to and from disk.
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ME: Wanna see Guardians of the Galaxy on August 2nd?
WIFE: What is it about?
ME: Uhhh... it is... uh... it is set in 19th Century England and it is a story about class struggle... and ... er.. .love and it stars, eh... Nicole Kidman, Hugh Grant and it is directed by Kenneth Branagh.
WIFE: Sure, I'll go.
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MehGerbil wrote: August 2nd
Headlines Aug 3rd
A man was brutally slain by his enraged wife when she discovered that he lied to her about the movie being a chick flick. Film at 11.
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Oddly enough, that news report sounds more interesting then the movies she drags me to...
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You not none of these people who feel agoraphobic when you are not in the dog box..
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If your wife is smart, she'll just smile and wait. The time will come when she takes you to a movie, taking away all sharp instruments and rope and make you sit through it. Something like Twilight, only worse.
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Pay back is a bitch.
Once you lose your pride the rest is easy.
I would agree with you but then we both would be wrong.
The report of my death was an exaggeration - Mark Twain
Simply Elegant Designs JimmyRopes Designs
I'm on-line therefore I am.
JimmyRopes
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That's one of the more useful things you learn in the military: The ability to sleep in any place, position or situation. Bonus points for loud snoring.
The language is JavaScript. that of Mordor, which I will not utter here
I hold an A-7 computer expert classification, Commodore. I'm well acquainted with Dr. Daystrom's theories and discoveries. The basic design of all our ship's computers are JavaScript.
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When I'm tired I can sleep anywhere. Anywhere but bed.
I have slept in a nightclub - took clients there and they were quite happy with the local seamstresses.
Planes I can be out before the safety announcement.
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Something worse than Twilight?
You are in a dark place, my friend.
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