hadoop - Should map() and reduce() return key/value pairs of same type? -

-

एक MapReduce नौकरी लिखते समय (विशेषकर Hadoop यदि प्रासंगिक हो), तो एक को मानचित्र () को परिभाषित करना चाहिए और एक कम करें () फ़ंक्शन, दोनों कुंजी / मान युग्म के अनुक्रम प्रदान करते हैं।

शब्द गणना के विहित उदाहरण में, दोनों कार्यों के प्रकार (स्ट्रिंग, int) के युग्म उत्पन्न करते हैं कुंजी एक शब्द और मूल्य की घटनाओं की गिनती के साथ। यहां- साथ ही साथ मैंने अन्य सभी उदाहरणों में देखा है- आउटपुट किए गए कुंजी और वैल्यू के प्रकार दो फ़ंक्शंस के बीच संगत हैं।

कुंजी / मान जोड़ी का प्रकार map () और कम करें () MapReduce के किसी भी आवेदन के भीतर ही हो सकता है? यदि हां: क्यों?

नहीं जाहिर है, ज़ाहिर है, मानचित्र के लिए आउटपुट जोड़े के प्रकार और कम से कम इनपुट जोड़े समान हों, क्योंकि एक को दूसरे में दिया जा रहा है।

यह काफी संभव है, हालांकि, यह संभव है कि आप कार्य को कम कर सकें कि आउटपुट मानचित्र जोड़े से आए एक अलग प्रकार की तुलना में - उदाहरण के लिए, यदि नक्शा कार्य में किसी दस्तावेज़ में शब्द गिना गया हो, लेकिन कार्य को कम किया जाए एक औसत शब्द आवृत्ति गणना उस स्थिति में मानचित्र पूर्णांक होगा, लेकिन कम से कम अस्थायी बिंदु संख्याओं का उत्सर्जन होगा।


Comments

Post a Comment

Popular posts from this blog

MVP, design question -

-
I am working on an MVP designated application and there are some design questions: I presenter how to communicate while writing code in the layer Should go between different presenters / ideas? Let's say I have a window window with a window viewer and I want to set the window title on the window from the second window. I have a title-setter on the window view, which wraps the actual Gui title. Should I call the title-setter directly on the scene (window viewer.tit = "title") or should I wrap the view title as the presentation title setter (window-creator.tit = "title")? Ask yourself how you will test it? If you do a window presentation. View. Tight = "Title", how can you test that the presenter is setting the title?
Read more

excel - Populate list via a bi-Condition -

-
I'm interested in implementing something but I'm not sure it would be possible and would like to take it on. This is my scenario: I will have two verification cells, which will be shown as a list, from which I will select. This is my condition that I want to remember and remember my list from a database. I have a list of agents, which has been thrown at B13: B23 and the next two, I have columns of data that assume that my data base looks like this bcdx | Y Z Agent 1 1 | 1 | 0 Agent 2 0 | 1 | 0 Agent 3 0 | 1 | 1 agent 4 1 | 0 | 0 ... I want to populate a list named agent from column B, when I verify cell 1: x and verification cell 2: 1 I choose from. It should only show an agent in column X with column: agent1 agent4 or 0 ... I read somewhere Array formula but I do not know if this is convenient and I have unfortunately not any background in the macro :( But I know C ++ is quite easy with some conditional statement like this. Advance Thanks, This
Read more

iphone - How do I make a UIPickerView in a UIActionSheet -

-
Just want to know how I will create UIPickerView in a UIActionSheet with a simple array. Well, I really know how to put it in an action sheet but I like my way because it is more for my app, thanks, but I I also want to know how to put options in UIPKviewView, I just have an array with colors already on top of that part: red, green, blue, yellow, black, etc. in this, but I want to know how it In the preview d L'be if I am using the already Instifrem:? Please help anyone. I know that this is a stupid question, but I'm cheating my head on my $$$$$$ MacBook. Instead you want to do this, create your UIPickerView interface builder and have it in your view controller Connect to the outlet. Add it as a subview of your main view and set its frame coordinates so that it is offset right below the edge, x = 0, y = 480 Then, when you want to display a picker, animate it like something with the screen: [UIView startup permissions: zero reference: zero]; [Color picture setfr
Read more