You where asked to help with the library system. It's simple SQL db with three tables User, Book and Borrow. Borrow table is journal. For each change in library - borrowing - you will have new row. E.g when you borrow a book, you will have new row in Borrow table with current timestamp. When you will return the book, you will have new row in Borrow table with current timestamp.
Below you can find schema for them:
User
| id | name |
|---|
| def reduceBy[A, B](merge: (A, A) => A)( | |
| by: A => B | |
| )(ds: Dataset[A])(implicit session: SparkSession, encoderA: Encoder[A], encoderB: Encoder[B]): Dataset[A] = { | |
| def reducePartition(iter: Iterator[A]): Iterator[A] = { | |
| iter.toList | |
| .groupBy(by) | |
| .mapValues(values => values.reduce(merge)) | |
| .values | |
| .toIterator |
I hereby claim:
To claim this, I am signing this object:
Because of problems defined in (Hadoop is like elephant crushing) :
I want to define requirements for data lake from perspective of:
I hereby claim:
To claim this, I am signing this object:
| /* | |
| OOP modeling | |
| */ | |
| //class | |
| function Man(firstName, secondName, age, sex) { | |
| //public | |
| this.firstName = firstName; | |
| this.secondName = secondName; | |
| this.age = age || 0; |
| GET "LIBHDR" | |
| LET START() BE | |
| $( | |
| WRITES("Hello, world!*N") | |
| $) |
| package main | |
| import ( | |
| "flag" | |
| "fmt" | |
| "io/ioutil" | |
| "log" | |
| "strconv" | |
| "time" | |
| ) |