Re^2: Efficient way to handle huge number of records?

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Re^3: Efficient way to handle huge number of records? by BrowserUk (Patriarch) on Dec 11, 2011 at 12:11 UTC
Hm. You're stretching several boundaries beyond their limits there: The 32bit memory mapping system supports either 4GB of address space without PAE or 64GB with PAE. But that does not necessarily tell you how much Linux supports with/without PAE. Linux also introduces constraints on total physical memory based on interactions with the way it manages kernel virtual memory. That leads to at least four different levels of memory support based on choices made during kernel build. The lowest level is 896MB without PAE The next level is about 3.25GB (bios limited) without PAE The next level is, I think, about 16GB, with PAE The highest level, I think, is the full 64GB with PAE plus an ugly kludge in kernel virtual memory (I think a bad idea. Use 64bit instead for that much ram). Win32 can also (and I believe was first) to do Page Address Extension (PAE). It can also extend the default 2GB user space to 3GB per process. But just like linux, these limits are extended through a series of cludges that have drawbacks as well as benefits. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]
Re^4: Efficient way to handle huge number of records? by Marshall (Canon) on Dec 11, 2011 at 12:30 UTC
Yes, even Windows 32 bit XP can go to 3GB for a user, but there can be problems if that feature is enabled. This appears to be a job for a DB, if many searches will be performed after the DB is "built" (initialized and indexed). From the problem statement, I think that SQLite will do the job just fine. At such time that it does not, then the SQL will work on another DB.	[reply]
Re^5: Efficient way to handle huge number of records? by BrowserUk (Patriarch) on Dec 11, 2011 at 13:46 UTC
This appears to be a job for a DB, if ... See Item 3. The "if" is crucial. Personally, I can see no logic at all in running a 32-bit OS on 64-bit hardware. 32-bit Perl on 64-bit OS has one advantage -- at least in the Windows world -- that of more XS modules build successfully. But even on windows, the stuff that doesn't tends to be either abandon-ware or the weird esoteric stuff like POE and Coro which either will never work with Windows or despite themselves if they do. But for the most part, a 64-bit build of Perl on a 64-bit OS with 8/16/32/64GB of ram just makes doing anything involving the huge datasets that typify genomic work so much easier. When you can pick up 8GB of ram for Ł29, it makes no sense to try and squeeze the large datasets typified by genomic work through 2 or 3GB memory pools. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]
Re^6: Efficient way to handle huge number of records? by Marshall (Canon) on Dec 11, 2011 at 14:21 UTC
Re^4: Efficient way to handle huge number of records? by flexvault (Monsignor) on Dec 11, 2011 at 18:14 UTC
BrowserUk I don't have any real experience with 32bit Linux machines with more than 2GB of memory, so your knowledge in this area is gospel. The specs said it could, but I didn't realize it was a hack. I do have more experience with 32/64bit Unix machines, and found that most 64bit applications (including Perl) required more than twice the real memory as on a 32bit Unix. Now, I haven't checked this in quite a while, so I'll have to revisit that. It could have been the 64bit version of the compiler or something else. I will be installing an IBM power 7 p-series p740 with 128GB in January. I will try some benchmarks and let you know. Power 7 is only 64bit. Thank you "Well done is better than well said." - Benjamin Franklin	[reply]
Re^5: Efficient way to handle huge number of records? by BrowserUk (Patriarch) on Dec 11, 2011 at 18:22 UTC
I will be installing an IBM power 7 p-series p740 with 128GB in January. 12 (or 16) cores, 48 (or 64 threads) 3.7(or 3.55)GHz. Drool! Slobber! :) With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]
Re^6: Efficient way to handle huge number of records? by flexvault (Monsignor) on Dec 11, 2011 at 21:26 UTC