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How important is the order of columns in indexes?
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Look at an index like this:
Cols
1 2 3
-------------
| | 1 | |
| A |---| |
| | 2 | |
|---|---| |
| | | |
| | 1 | 9 |
| B | | |
| |---| |
| | 2 | |
| |---| |
| | 3 | |
|---|---| |
See how restricting on A first, as your...
Measure time in Linux - time vs clock vs getrusage vs clock_gettime vs gettimeofday vs timespec_get?
... This clock wraps around once it tops out (this typically happens after ~2^32 ticks, which is not very long for a 1 MHz clock). man clock says that since glibc 2.18 it is implemented with clock_gettime(CLOCK_PROCESS_CPUTIME_ID, ...) in Linux.
clock_gettime(CLOCK_MONOTONIC, ...) provides nanosecond ...
Mongo interface [closed]
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RobIII
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answered Nov 25 '10 at 3:02
Justin JenkinsJustin ...
“FOUNDATION_EXPORT” vs “extern”
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173
If you look in NSObjCRuntime.h (in Foundation) you will see that FOUNDATION_EXPORT compiles to e...
How do I assert equality on two classes without an equals method?
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23 Answers
23
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Checking if a folder exists (and creating folders) in Qt, C++
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– Jonas G. Drange
Apr 27 '16 at 20:33
1
Why it isn't static? QDir::exists("absolutepath") and QD...
Namespace for [DataContract]
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434
DataContractAttribute Class is in the System.Runtime.Serialization namespace.
You should add a...
Java: Best way to iterate through a Collection (here ArrayList)
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answered Mar 8 '11 at 5:31
MAKMAK
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How to do a PUT request with curl?
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theabrahamtheabraham
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