In a data lake, data stored internally in a repository. You can call it a blob. The data in the lake a no-format data, but you need a schema for the database.  Data lake Repository Database In the database, the Schema definition you need before you store data on it. It should follow Codd's rules. Here data is completely formatted. The data stores here in Tables, so you need SQL language to read the records. Poor performance in terms of scalability. Data lake It doesn't have any format - it's just a dump. You can send this dump to the Hadoop repository for data analysis. This repository can be incremental. You can build a database. The data lake is a dump of data with no format. It needs a pre-format before it sends for analytics. Data security and encryption: You need these before you send data to Hadoop. In real-time, you need to pre-process data. This data you need to send to the data warehouse to get insights.

The next step after installing R is how to run commands. You can run directly by entering commands. The other way is you need to write an R script, that contains all the series of commands. The benefit of the script is you can save your commands, it saves your time. Second, as a script, you can run it whenever you need. #How to Run-commands in R: Executing Commands in R Commands can be entered directly into the R console (the window that opens when you start R), following the red > prompt, and sent to the computer by pressing enter. For example, typing 1 + 2 and pressing enter will output the result 3: > 1+2 [1] 3 Your entered code always follows the > prompt, and output always follows a number in square brackets. Each command should take its own line of code, or else a line of code should be continued with { }  It is possible to press enter before the line of code is completed, and often R will recognize this. For example, if you were to type 1 + but then pr

The PostegreSQL is a popular database for web applications. You can manage user data in this database conveniently. #postgreSQL What is PostgreSQL Web applications started using NoSQL databases. PostgreSQL is updating their database to meet the requirements of web applications. So PostgreSQL is almost equal to NoSQL database. Java Script PostgreSQL supports  JSON (JavaScript Simple Object Notation) . JSON is portable data format to share data. The MongoDB follows JSON. PostgreSQL's structured format for saving JSON, called JSONB, eliminates the need for restructuring a document before it is committed to the database. Benefits  PostgreSQL is similar to MongoDB to ingest documents  PostgreSQL follows ACID compatibility  PostgreSQL have all the features and options to edit JSON data.

Below are the top Tableau features for data analytics. Tableau 9 for Data Science engineers. CONNECTING TO LOCAL FILE  Tableau can connect to any local file or database such as Excel  Text File Access  Statistical File, or  Another Database file CONNECTING TO SERVER Tableau can connect to your data server too. It can connect to almost any type of data server. Below are some of the most popular databases that Tableau can connect: Tableau Server Google Analytics Google BigQuery Hortonworks Hadoop Hive MapR Hadoop Hive IBM DB2 IBM BigInsights IBM Netezza Microsoft SQL Server Microsoft Analysis Services Oracle Oracle Essbase MySQL PostgreSQL SAP While working on Tableau, data can have Live Connection where any change in the source data will be automatically updated in Tableau. On the other hand, data can be Extracted to the Tableau repository so that any change made here will not affect the original source data. CONNECTING TO EXCEL FILE To connect