Why not a LinkedMap interface for LinkedHashMap?

I`m currently cleaning my null-rejecting collection framework and I found the LinkedHashMap in the Collection framework. Why doesn`t this class have an interface LinkedMap? The autor of the class, Joshua Bloch, tells in his 'Effective Java: Programming Language Guide' to use interfaces to design from. Why did he not do this himself??

Just because LinkedHashMap exactly implements Map and nothing more. What would be the benefit of an extra interface LinkedMap, which would most likely extend Map and add nothing more?

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Why not leave remote app for 4.2.1?

Hi there, with my family i own 3 ipod touches, 3 shuffles, and two iphones. I own two houses where i have set up a central computer to run itunes with airport expresses all over my houses to control speakers and music through the "remote" app. I am heavily invested in apple products and apps. My use of apple technology for our media enjoyment is truly great and never ceases to amaze guests. I LOVE "remote" and airport.
Since i have had to restore all my ipods for various reasons, i am now no longer able to download the remote app since apple only supports iOS 5 or later. They have instantly rendered my whole apple setup useless. This is extremely disapointing and they are basically telling me that my purchase of their hardware was a mistake and that they only care about people who purchase new things. Which is a great reason not to purchase new things from them.
What i don't understand is why they simply can't put a version of remote in the app store for iOS 4.2.1. You obviously have it, so why not just put it there?????
So little effort to leave 4.2.1 apps in the store. They could even create a special section based on iOS.
Now they are forcing me to consider alternative solutions, of which there are many. I simply would never have bothered to do this before since i was so satisfied with apple products. They are literally forcing me to look at alternatives and this is a failure on their part from a business and marketing perspective.
Now i will most likely go from an evangelizer of apple products to a hater. It is simply disrespectful how theyare treating people with old products...

Interesting. It really boggles me why they would do this. Seems it would be easy to seperate the app store into pre and post 4.3?
The devices i have work perfectly fine and do everything i need them to. I don't want to buy new devices. It is an awful stance to take and i find it very insulting. Is this not a big issue with users out there? Or is everyone just buying new stuff all the time?

Why not use Redo log for consistent read

Oracle 11.1.0.7:
This might be a stupid question.
As I understand if a select was issued at 7:00 AM and the data that select is going to read has changed at 7:10 AM even then Oracle will return the data that existed at 7:00 AM. And for this Oracle needs the data in Undo segments.
My question is since redo also has past and current information why can't redo logs be used to retreive that information? Why is undo required when redo already has all that information.

user628400 wrote:
Thanks. I get that piece but isn't it the same problem with UNDO? It's written as it expires and there is no guranteee until we specifically ask oracle to gurantee the UNDO retention? I guess I am trying to understand that UNDO was created for effeciency purposes so that there is less performance overhead as compared to reading and writing from redo.And this also you said,
>
If data was changed to 100 to 200 wouldn't both the values be there in redo logs. As I understand:
1. Insert row with value 100 at 7:00 AM and commit. 100 will be writen to redo log
2. update row to 200 at 8:00 AM and commit. 200 will be written to redo log
So in essence 100 and 200 both are there in the redo logs and if select was issued at 7:00 data can be read from redo log too. Please correct me if I am understanding it incorrectly.I guess you didnt understand the explaination that I did. Its not the old data that is kept. Its the changed vector of Undo that is kept which is useful to "recover" it when its gone but not useful as such for a select statement. Whereas in an Undo block, the actual value is kept. You must remember that its still a block only which can contain data just like your normal block which may contain a table like EMP. So its not 100,200 but the change vectors of these things which is useful to recover the transaction based on their SCN numbers and would be read in that order as well. And to read the data from Undo, its quite simple for oracle to do so using an Undo block as the transaction table which holds the entry for the transaction, knows where the old data is kept in the Undo Segment. You may have seen XIDSEQ, XIDUSN, XIDSLOT in the tranaction id which are nothing but the information that where the undo data is kept. And to read it, unlke redo, undo plays a good role.
About the expiry of Undo, you must know that only INACTIVE Undo extents are marked for expiry. The Active Extents which are having an ongoing tranaction records, are never marked for it. You can come back after a lifetime and if undo is there, your old data would be kept safe by oracle since its useful for the multiversioning. Undo Retention is to keep the old data after commit, something which you need not to do if you are on 11g and using Total Recall feature!
HTH
Aman....

Why is the tethering interface for iPhone5 ordered from Apple not in the Settings app while an iPhone5 ordered from Verizon does have the tethering setting present?

My girlfriend and both bought iPhone5's and are on the family plan. I bought mine through the Apple store and she through Verizon directly. In her settings app the tethering interface is present, in mine it is not. Anyone how to or know who to contact to get my phone purchased through the apple store to get this enabled.

Contact Verizon & make sure Tethering is provisioned on your account. That setting won't appear if it's not.

Mega 651:Why not 1 single receiver for all ?

I have a Mega 651 with Celron 2,6 Ghz. proc. in it.
Also Maxtor 120 Gb harddisk 7200 rpm.
I use the internal Sis VGA card.
With 512 DDR 2 ram
Included is 1 IR transmitter (gris color).
I bought also a MSI TV @nywhere Master card. With IR transmitter and IR receiving eye included.
Why am I NOT able to use the internal IR receiver eye that is build in the Mega 651 for controlling my TV from Intervideo MSIPVS??
Why do I need to place the add. IR receiver eye. The one that comes with my TV tuner card?
Is there no way I can control my TV with my IR control from my Mega 651 and with the INTERNAL IR eye in my Mega PC?
Pretty stupid.

This are the details from my MSI MEGA 651 deluxe
Technische Daten:
Prozessor Sockel
Intel Pentium 4 - Sockel 478 (keine CPU enthalten!) bis 2,8 GHZ FSB400 oder FSB533 auch alle Celeron Prozessoren
Chipsatz
SIS 651
Front Side Bus
@400/533MHz
Arbeitsspeicher
2xDDR DIMM (kein Speicher enthalten) PC266/333 max 2GB
Steckplätze
1xPCI,1xAGP (4x)
Erweiterungseinschübe gesamt
1 x von vorne zugänglich - 5.25" x 1/2H (keine Laufwerke enthalten)
1 x Intern - 3.5" x 1/3H
OnBoard Komponenten
Sound: Realtek ALC650 5.1 Sound
VGA-Grafik SIS 720 32MB shared
LAN-Kontroller 100mbit (dsl-fähig)
IEEE1394/Firewire und USB2.0 (6x)
Abmessungen/Format
202(B) x 151(H) x 320(T) mm
Front I/O:
• Mic-in/Head-Phone
• 2x USB
• IEEE 1394
• Optical SPDIF-in
• 6 in 1 Card Reader integriert
Rear I/O:
• COM / VGA / Parallel
• 2x PS2
• LAN on-Board
• 2x USB
• Optical SPDIF-out
• Speaker-out/Line-in/Mic-in (AC`97 Codec, 5.1ch)
• Modem
• PSU: 200W PFC
Hi-Fi Modus
Voll funktionsfähig auch ohne PC-Aufrüstung:
• FM/AM-Radio
• Audio-CD
• MP 3-CD
• Equalizer & CM

I am not viewing message interface for sender service in sender agreement

Hi Experts,
Right now we have one interface setup in XI for sending the data to three customers using BPMs.
Now i want to add to one more customer in to current xi setup and send the data.
so i have created all the types like message type, message interface and interface mapping.
Already i have scenario in ID i have created Comm channles.
so when i create sender agreement i am unable to find message Interface which i have created in IR for sender business service.
I have not created new scenario but using the same scenario.
Kindly help me out from this.
Appreciate for your response.
Thanks,
Bhasker

Hi,
Make sure to add the inbound and outbound message interfaces in the Business Service so that they will be available in Sender Agreement.
Hope this helps.
Thanks and Regards,
Kalpesh

SSD and CFQ - why not, it has support for it

Hello,
in wiki its stated it is better to switch to deadline or noop instead of default cfq scheduler for SSD disks. But, I quote:
""CFQ has some optimizations for SSDs and if it detects a non-rotational
media which can support higher queue depth (multiple requests at in
flight at a time), then it cuts down on idling of individual queues and
all the queues move to sync-noidle tree and only tree idle remains. This
tree idling provides isolation with buffered write queues on async tree."
https://www.kernel.org/doc/Documentatio … osched.txt
So why change to deadline or noop?

Before discussing IO schedulers and what they are needed for let's look at a rotational device (HDD, spindle). Such device has spinning disks and head that physically moves to required location. Such structure leads to following characteristics:
- random latency it quite high, for modern HDD it is ~10ms (let's ignore disk controller write buffer).
- sequential access provides much higher throughput. In this case head needs to move less distance.
In case if we have a lot of running processes that make IO requests to different parts of storage (i.e. random access) then we can expect that a disk handles ~100 IO per second. Because modern systems can easily generate load much higher than 100 req/sec we have a queue of requests that have to wait for access to the storage. One way to improve throughput is to linearize access i.e. order waiting requests by its logical address and always choose closest request. Historically this was the first linux IO scheduler called elevator scheduler.
One of the problems with elevator algorithm is that it makes suffer processes with sequential access. Such processes read a block of data then process it for several microseconds then read next block and so on. Elevator scheduler does not know that the process is going to read another block nearby and thus to moves to another request at some other location. To overcome the problem anticipatory IO scheduler was added. For synchronous requests this algorithm waits for a short amount of time before moving to another request.
While these scheduler try to improve total throughput they also might leave some unlucky requests waiting for a very long time. Imagine majority of processes make requests at the beginning of storage space while an unlucky process makes process at the other end of storage. So developers tried to make algorithm more fair. Thus deadline scheduler was added. It has a queue ordered by address (the same as elevator). If some request sits in this queue for a long time then it moves to "expired" queue ordered by expire time. Scheduler check expire queue first and process requests from there and only then moves to elevator queue. It is important to understand that this algorithm scarifies total throughput for fairness.
CFQ (the default scheduler nowdays) aggregates all ideas from above and adds cgroup support that allows to reserve some amount of IO to a specific cgroup. It is useful on shared (and cloud) hostings - users who paid for 20 IO/s want to get their share if needed.
Now let's look at characteristics of SSD. It does not have moving parts. Random access as fast as sequential one. SSD can handle multiple requests at the same time. Modern devices' throughput ~10K IO/s that is higher than workload on most systems. Essentially user cannot generate enough requests to saturate SDD, the requests queue is effectively always empty. In this case IO scheduler does not provide any improvements. Thus it is recommended to use noop scheduler for SSD.
As for phoronix benchmarking - its results look sketchy to me. I would expect that noop is slightly better than deadline with difference at the measurement noise level.

Why not adding a reminder for missed calls by pushing notifications to all the platform

en Why not

iCloud does not have support for telephone calls. iCloud for Mac would not be the proper place to put notifications for something not supported by the product. Perhaps you wanted to make a suggestion to the iPhone team?

Why not add a scale for accessing both scaleX and scaleY (class extensions in as3?)

I've considered and am suggesting there be a scale for both scaleX and scaleY (via a setter & getter function)
I think that one might get confused trying to get a value out of scale if scaleX and scaleY are different, but...
You could throw an error when using a variable scale (getter only) if they (scaleX&scaleY) are different, and return the value if they are the same.
It could throw more a warning and return the scaleX or scaleY or an average, and or possible have a policy (although again I can see this may seem potentially more confusing.)
I remember with ObjectiveC you could/can create a class extension that would extend a class that already exists pervasively like String.
This way you could alter functionality like this where all onjects have inheritend from a DisplayObject or whereever scaleX & scaleY are. Subclass as an Extension Class this deep lying class and add that kind of ability without needing to do it to all of your higher level classes (or other such tricks String Utility Classes etc.), which as I recall existed in ObjectiveC (and other langauges) no doubt because it was simply impossible to achieve the same effect any other way.
Is there such a way in AS3 to extend a class? Is it impossible for some reason?
May appologies if I've got the terminalogy wrong, please clarify if I'm searching for the wrong keyword on this thanks.
Anyway I still think putting something like
myCircle.scaleX *= 0.9;
myCircle.scaleY *= 0.9;
or
myCircle.scaleY = myCircle.scaleX *= 0.9;
or
myCircle.scaleX *= 0.9;
myCircle.scaleY = myCircle.scaleX;
is not as nice clean as
myCircle.scale *= 0.9;
would be. I think my thoughts on explaination for why and a simple possible selection of solutions (throw catchable/discargable errors/warning or alterable policies).

TCP has retry logic. The timeout period varies by OS and configuration. TCP will typically retry three times and wait for the timeout period to expire before reporting an error. I do not believe any OS will fail in less than two minutes with the standard timeout and some systems go to 5 minutes.

Why Not i OS 8 for iPhone 4 . Are we supposed to stuck in iOS 7.1.2 ?

Please let us know when you are going to bring iOS 8 for Iphone 4 ?

Apple is not here; you are posting to people just like you--end users. None of us are Apple employees or agents. If you want to get your concerns to someone at Apple, please use this link:
http://www.apple.com/feedback/iphone.html
However, Apple history says what you desire will not happen.

Why not Multi-Touch Gestures for iPad 1 Apple?

Why?????

I'm curious, what's buggy about the gestures? I've had an iPad 1 running multitouch gestures for months, and haven't noticed any issues. Granted, the gesture I use most of the time is the four-finger swipe-up to reveal recent apps, but I often swipe between Safari and iThoughts when doing research. *Love* the feature, and I'm staying at iOS 4 for the time being until I see what Apple's next move is on this. Other iOS 5 features aren't compelling enough to lose gestures, in my view.
One thing I've learned about updates: always let someone else be the first to adopt them, then check forums a day or two later to find out where the pitfalls lie. I would've been pretty peeved if I'd have read the copy on Apple's website that called out the gestures as an iPad feature rather than exclusive to iPad 2, then installed and lost gestures. People are justifiably ticked off about that, I think (and yes, I've sent feedback to Apple to share that opinion --- it can't hurt to try.)

Why not use gift card for family sharing?

This family sharing feature seems great. But long gone are the days where I had a credit card on file. These days I only use gift cards. But system really wants me to have a credit card to activate this family sharing? Has anyone been able to do with pure gift cards?
thanks

Hi Kestelli,
In order to set up Family Sharing the family organizer must have a credit card or debit card to use for billing. See this article -
Family purchases and payments
If a family member, including the organizer makes a purchase and has gift or store credit, that purchase is first billed to that credit. Family members purchases may not be billed to the organizers store credit unless they are the organizer. See this article -
How iTunes Store purchases are billed
Thanks for using Apple Support Communities.
Best,
Brett L

Why not reduce the price for the pre-installed Aperture3?

On the configuration page for the MBP, I find the cost for the Aperture 3 remain £173.00.
I wish it preinstalled but it would be much cheaper to purchase through the App store.
Is the premium paid to obtain a Aperture 3 CD? I am mystified.
What is best for the stability of Aperture 3 ?-Pre installed [pay the premium] or down load from the the App store without an Aperture 3 cd?
Regards

So, I ordered a new MBP with Aperture pre-installed for $199.99 before checking out the Aperture page on Apple.com and seeing that it was available for $79.99.
I called Apple immediately to change the configuration of my computer and have it removed.
They seemed perplexed. Nice, but confused. How could this be true?
Truly.
But it is true, and once they realized it, they sympathized. They told me that they would reconfigure the computer. I asked if it would be possible for Apple, since they were charging $79.99 for the software, to simply reduce the price to that # for the preinstall?
The operator left and came back, saying she was able to have the price of the computer reduced by $100.
Which is great. I asked if changing the configuration of the computer would cause a delay in shipping - she suggested it would, but realizing that I didn't find it just to pay even $10 more for an application to be pre-installed, she asked if I'd like her to try to have the difference removed. I said, why yes, thank you.
She came back to say that the price would be matched.
So, I'm getting Aperture pre-installed for the App store price.
I bet you can too.

HT201079 Family sharing : Why not ask to buy for adults ?

I don't see why we can't turn on "ask to buy" for adults. I want to control what I share....

As far as I know Apple haven't said why (these are user-to-user forums), only that you can't - you can try leaving feedback for Apple and maybe in the future it will be possible : http://www.apple.com/feedback/itunesapp.html

Why not use Fourier transforms for filtering?

Are there any resources for constructing filters using discrete Fourier transforms (DFTs)? Or is it as easy as it seems. For example, for lowpass filtering I obtain the DFT of my signal, zero out components above the selected cutoff frequency and then transform back to get my signal minus the high frequency (noise) components. It seems to behave correctly for the signal I've applied it to, but am I missing something. Upsides would appear to be (1) no time delay between the input and output and (2) the filter is sharp with no transition band. Downside is that this method is slower than using impulse filters, but are there other upsides, downsides, or considerations I'm missing?

The technique of filtering using frequency domain truncation and IFFT is used in specific areas where computation time is essential (to avoid the time domain convolution with a long impulse response), like image processing. However the technique also has some downsides you should be aware of.
The frequency domain filtering performed on a data record is totally equivalent to a circular convolution made on your time signal with the impulse response of your ideal low-pass filter (typically a sin(x)/x function). The fact what we are doing a circular convolution will result in unwanted artifacts and you'll see some "parts" of the beginning of your signal at the end of the filtered signal and vice-versa.
Try for example to create a short signal (like a sharp pul
se) and extend it with zeros. After filtering you will see a sort of "pre-shoot" of your original signal at the very end of your signal. If you then rotate your time signal you'll discover that the signal is actually continuous (in a circular way).
You can reduce the problem by, for example, adding "some" zeros at the beginning and at the end of your signal (zero-pad) before your filtering operation (before the FFT) and then remove these additional samples again from you filtered signal (after the IFFT).

Why not a LinkedMap interface for LinkedHashMap?

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