Neo4j supports Windows but the recommended filesystem is ext4 - neo4j

The Neo4j manual shows that windows is supported, but the minimum filesystem is Ext4, what are the compromises for NTFS.

Neo4J is written on java and uses JDK abstraction of file system. So developers can recommend you some operation system, but theoretically it will work on FAT or even on proprietary OS of your cooler (if it is run with Java control).
Just provide your own measurement of performance at possible target OS and select best one.

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Difference between bundled Graal VM and other VMs + Graal JIT

IIUC, GraalVM project provides new JIT compiler which should work with any JVM distribution (OpenJDK, Oracle, Amazon Corretto) however, GraalVM website also provides bundled downloads which are based on OpenJDK.
So, what's the difference between using Graal JIT with other distributions VS using Graal's own distribution? Does Graal further optimizes JVM in their own distribution?
The new JIT compiler should work with any JVM that implements JEP243 Java-Level JVM Compiler Interface, which is implemented only by HotSpot JVM at the moment. The GraalVM team provides backports of it to open/oracle JDK8 and it is included in JDK9 and later. For other distributions (Amazon, etc.) it depends on what HotSpot version they are based off.
You can run Graal Compiler that is bundled with JDK9+ by using these options (I think it works only on Linux):
-XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -XX:+UseJVMCICompiler
You're going to have an easier time using GraalVM as everything is set-up there already and you get the newest GraalVM Compiler. On top of that, GraalVM provides additional features like native-image for faster startup and low memory footprint of Java programs, dynamic languages like JavaScript, Python, Ruby, and R, and more. Moreover, there is an enterprise edition of GraalVM that, among other things, contains further optimizations.
References:
https://www.graalvm.org/ for more details on the features
https://renaissance.dev for benchmarks of both community and enterprise versions of GraalVM

Bazel repository rule- Can I access something like Java's "os.arch"?

I need to write a Bazel repository rule which downloads mysql binaries according to the required version, to the operating system and the architecture.
I'll get the required version from the user, the operating system from repository_os.name but I'm not sure how I can access the architecture?
The current non-hermetic code uses os.arch as a good enough heuristic (yes I know it's not precise).
There is no way to access the architecture, except asking for uname -m using repository_ctx.execute. You can also make it work on Windows by executing a different command depending on repository_ctx.os.name (which is the same as os.name from the JVM so if it contains win you can execute the Windows command). If you think this is needed, please file a feature request on https://github.com/bazelbuild/bazel/issues/new
The host platform's CPU architecture and operating system name are accessible via repository_ctx.os. The attribute is a repository_os struct with arch and name.

what is the utility of the buildroot on beagleboneBlack?

I don't understand what is the reason of buildroot of a card such as beaglebone black where as it has a Linux system when we bought.What is the utility of the buildroot?
Build a completely custom, lightweight, and fast-booting embedded Linux system?
Buildroot is a set of Makefiles and patches that makes it easy to generate a complete embedded Linux system.
Buildroot can generate any or all of a cross-compilation toolchain, a root filesystem, a kernel image and a bootloader image.
It is useful mainly for people working with small or embedded systems, using various CPU architectures (x86, ARM, MIPS, PowerPC, etc.) : it automates the building process of your embedded system and eases the cross-compilation process.
The resulting root filesystem is mounted read-only, but other filesystems can be mounted read/write for persistence.
Although user accounts can be created, in practice almost everything is done as root. Buildroot uses no package manager.
Instead, package selection is managed through make menuconfig.
source http://elinux.org/BeagleBone_Operating_Systems

How to install Torch on windows 8.1?

Torch is a scientific computing framework with wide support for machine learning algorithms. It is easy to use and efficient, thanks to an easy and fast scripting language, LuaJIT, and an underlying C/CUDA implementation.
Q:
Is there a way to install torch on MS Windows 8.1?
I got it installed and running on Windows (although not 8.1, but I don't expect the process to be different) following instructions in this repository; it's now deprecated, but wasn't deprecated few months ago when I built it. The new instructions point to torch/torch7 repository, but it has a different structure and I haven't been able to build it on Windows yet.
There are instructions on how to install Torch7 from luarocks, but you may run into issues on windows as well; I haven't tried this process. It seems like there is no official support for Windows yet, but some work is being done by contributors (there is a link to a pull request in that thread).
Based on my experience, compiling that deprecated repo may be your best option on Windows at the moment.
Update (7/9/2015): I've recently submitted several changes that fix compilation issues with mingw, so you may try the most recent version of torch7 and follow the build instructions in the ticket. Note that the changes only apply to the core lib and additional libraries may need similar changes.
This webpage hosted by New York University recommends installing a Linux virtual machine in order to run Torch7 on Windows through Linux. Another option would off course be to install a Linux dist in parallel with Windows 8.
Otherwise, if you don't mind running an older version of Torch, there is a Windows installer for Torch5 at SourceForge.
I think to use a GPU from inside the virtual machine, the processor and the motherboard should not only support VT-x , but VT-d should be supported too.
But the question is, if I use a CPU with VT-d supported, do you think there will be a significant loss in PCIe connections efficiency?
From what I understand,
VT-d is important if I want to give the virtual machines direct access to my hardware components (like PCI Express cards). Like directly attach graphics card to vm instead of host machine. Isn't that mean that the PCIe connections efficiency will be the same just like if it was the host?

How do I back up and restore my Delphi settings? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How to migrate Delphi or clone Delphi registry settings?
I need to format my PC soon, but I have the IDE and environment settings perfectly set up to just how I want them, along with some components I have installed.
Obviously formatting and reinstalling Windows will wipe all settings and registry entries, so when I do install Delphi again I will have to tweak it all to get it to how it originally was, which will take quite a bit of time that I would rather not use up.
What is the best way to retain Delphi IDE and environment settings and installed components?
Is it just a case of backing up registry entries and user data folders?
How to make a complete backup of delphi XE manually:
backup complete installation folder.
(tip: install your components under the delphi folder so they also get backed up).
export & backup HKLM\Software\Embarcadero registry key
in case of 64 bit os it will be HKLM\Software\Wow6432Node\Embarcadero
export & backup HKCU\Software\Embarcadero registry key
Some components may write BPL files to your system folder (check C:\Windows\System32 or C:\Windows\SysWOW64 folder)
after OS reinstallation:
reinstall Delphi to the SAME folder and apply same updates
overwrite installation with your backup
reimport registry keys from backup
if you have Delphi plugins/experts, reinstall them
some tips:
install Delphi under the root of your drive (eg c:\DelphiXE), this to prevent troubles with UAC under vista/W7.
Keep your projects under the delphi folder, is very handy if you have to cope with different delphi versions (eg c:\delphi5\projects, c:\delphixe\projects, ...)
make an automated daily backup of your delphi folder (via windows backup or other tool)
You can try CnWizard Backup/Restore tool. If you keep same path for components and delphi install, just make backup, install delphi and cnwizard, copy all components folders and make restore.
I only have problem when migrate from XP to W764b, must to manualy change path in registry for Program Files folder.
Yes, I agree with #Martin, VMWare is great for this VMWare. Not only for Delphi and its settings and component, but the whole O/S, including SPs, KBs, drivers, settings, applications & their settings, Anti virus, Firewalls.
This is what I do with VMWare ver 5 (other/newwer version might be different)
Install VMWare on the Host O/S. The host can be a Windows O/S or a Linux O/S variant. I personally like to use Linux as the host O/S, because, for me, the security is better towards virus, malware etc.
Install a guest O/S. This can be any supported O/S of choice, including any SPs, drivers needed.
Install Delphi and all components you need.
You can backup the guest O/S to a media, DVD-R, for example. If anything major happened, you can just restore it for less than 30 minutes. This is a huge benefit.
You can have as many as guest O/Ses you want (If you have the space). This is great for testing purposes. How many times you hear that your app is breaking on a particular O/S, with a specific SPs/KBs, dll or other specific settings on client PCs? With multiple guest O/Ses, you can test your app with different O/S and/or settings without having to have multiple PCs or multiple partitions with different O/Ses.
Of course VMWare has many other usages, but for me, the above usage scenario is enough.
Other Virtual Machine is from Oracle (Oracle VM) which is free Oracle VM. They claimed to be better than VMWare, but I myself have not tested it.

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