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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...

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...

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...

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() { ...

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...

Debugging questions. When question is related to debugging specific exception always provide relevant traceback. While it is advisable to remove duplicated outputs (from different executors or attempts) don't cut tracebacks to a single line or exception class only. Performance questions. Dependin...

An example of a configuration function in SQL is the @@SERVERNAME function. This function provides the name of the local server that's running SQL. SELECT @@SERVERNAME AS 'Server' ServerSQL064 In SQL, most data conversions occur implicitly, without any user intervention. To perform any convers...

In your routes/index.js Here user is the model for the userSchema router.post('/login', function(req, res, next) { if (!req.body.username || !req.body.password) { return res.status(400).json({ message: 'Please fill out all fields' }); } passpor...

A common requirement for a Java application is that can be deployed by copying a single file. For simple applications that depend only on the standard Java SE class libraries, this requirement is satisfied by creating a JAR file containing all of the (compiled) application classes. Things are not ...

package main import ( "encoding/gob" "os" ) type User struct { Username string Password string } func main() { user := User{ "zola", "supersecretpassword", } file, _ := os.Create("user.go...

package main import ( "encoding/gob" "fmt" "os" ) type User struct { Username string Password string } func main() { user := User{} file, _ := os.Open("user.gob") defer file.Close() decoder := gob...

package main import ( "encoding/gob" "fmt" "os" ) type User struct { Username string Password string } type Admin struct { Username string Password string IsAdmin bool } type Deleter interface { Delete() } ...