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Hadoop is an open-source software framework for storage and large-scale processing of data-sets in a distributed computing environment. It is sponsored by Apache Software Foundation. It is designed to scale up from single servers to thousands of machines, each offering local comput...

In tables recording events there is often a datetime field recording the time an event happened. Finding the single most recent event can be difficult because it's always possible that two events were recorded with exactly identical timestamps. You can use row_number() over (order by ...) to make su...

from sqlalchemy import create_engine cnx = create_engine('mysql+pymysql://username:password@server:3306/database').connect() sql = 'select * from mytable' df = pd.read_sql(sql, cnx)

Typically, before developing a new HERE SDK application, you need to acquire a set of credentials by registering your application on http://developer.here.com. Each application requires a unique set of credentials. When you register your app, the registered bundle identifier must match the package n...

The pygame.mixer module helps control the music used in pygame programs. As of now, there are 15 different functions for the mixer module. Initializing Similar to how you have to initialize pygame with pygame.init(), you must initialize pygame.mixer as well. By using the first option, we initiali...

While chrome browser is open to any tab (except welcome tabs) you have three options to open Chrome Dev Tools: Keyboard: Type command ⌘+option+i Browser Menu: Click 'Menu' > 'More Tools' > 'Developer Tools' Program Menu (at top of your screen): Click 'View' > 'Developer' > 'Develope...

You use the FIRST_VALUE function to determine the first value in an ordered result set, which you identify using a scalar expression. SELECT StateProvinceID, Name, TaxRate,        FIRST_VALUE(StateProvinceID)         OVER(ORDER BY TaxRate ASC) AS FirstValue FROM SalesTaxRate; In this example,...

The LAST_VALUE function provides the last value in an ordered result set, which you specify using a scalar expression. SELECT TerritoryID, StartDate, BusinessentityID,        LAST_VALUE(BusinessentityID)          OVER(ORDER BY TerritoryID) AS LastValue FROM SalesTerritoryHistory; This example...

The LAG function provides data on rows before the current row in the same result set. For example, in a SELECT statement, you can compare values in the current row with values in a previous row. You use a scalar expression to specify the values that should be compared. The offset parameter is the n...

The PERCENT_RANK function calculates the ranking of a row relative to the row set. The percentage is based on the number of rows in the group that have a lower value than the current row. The first value in the result set always has a percent rank of zero. The value for the highest-ranked – or last...

The PERCENTILE_DISC function lists the value of the first entry where the cumulative distribution is higher than the percentile that you provide using the numeric_literal parameter. The values are grouped by rowset or partition, as specified by the WITHIN GROUP clause. The PERCENTILE_CONT functi...

Lets following are the class definition class A def a; end end module B def b; end end class C < A include B def c; end end What are the instance methods of C? C.instance_methods # [:c, :b, :a, :to_json, :instance_of?...] What are the instance methods that declare...

var passport = require('passport'); var LocalStrategy = require('passport-local').Strategy; passport.serializeUser(function(user, done) { //In serialize user you decide what to store in the session. Here I'm storing the user id only. done(null, user.id); }); passport.deserializeUser(funct...

In SQL, you use date and time data types to store calendar information. These data types include the time, date, smalldatetime, datetime, datetime2, and datetimeoffset. Each data type has a specific format. Data typeFormattimehh:mm:ss[.nnnnnnn]dateYYYY-MM-DDsmalldatetimeYYYY-MM-DD hh:mm:ssdatetim...

This is a complete example of all the commonly used SQLite related APIs. The aim is to get you up and running really fast. You can also get a runnable PHP file of of this tutorial. Creating/opening a database Let's create a new database first. Create it only if the file doesn't exist and open it f...

Haystack: The string in which given pattern needs to be searched. Needle: The pattern to be searched. Time complexity: Search portion (strstr method) has the complexity O(n) where n is the length of haystack but as needle is also pre parsed for building prefix table O(m) is required for building p...

Question: What is the output of code below and why? setTimeout(function() { console.log("A"); }, 1000); setTimeout(function() { console.log("B"); }, 0); getDataFromDatabase(function(err, data) { console.log("C"); setTimeout(function() { ...

Detailed instructions on getting nuget set up or installed.

When asking Apache Spark related questions please include following information Apache Spark version used by the client and Spark deployment if applicable. For API related questions major (1.6, 2.0, 2.1 etc.) is typically sufficient, for questions concerning possible bugs always use full version ...

Example Data Please try to provide a minimal example input data in a format that can be directly used by the answers without tedious and time consuming parsing for example input file or local collection with all code required to create distributed data structures. When applicable always include ty...