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You can use aggregate function SUM() with GROUP BY clause to achieve this.Let us create a table. The query to create a table is as follows −mysql> create table SelectPerMonthDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Price int, -> PurchaseDate datetime -> ); Query OK, 0 rows affected (2.34 sec)ExampleInsert some records in the table using insert command with one of them would be the date of purchase. The query is as follows −mysql> insert into SelectPerMonthDemo(Price, PurchaseDate) values(600, date_add(now(), interval -1 month)); Query OK, 1 row affected (0.42 sec) ... Read More
You can check the landscape of HANA system, navigate to Landscape tab in HANA studio. Services show all the services running on HANA system.The following screenshot shows SAP HANA system and all the key services running under system Landscape for the same system.You can see the service name corresponding to each server in HANA system landscape.
Consider a class Tester which has implemented Cloneable interface. Now you can initialize an object using following five ways:1. Using new keyword.Tester tester1 = new Tester();2. Using Class.forName() methodTester tester2 = (Tester)Class.forName("Tester").newInstance();3. Using clone method.Tester tester3 = tester1.clone();4. Using Constructor.forName() methodTester tester4 = Tester.class.getConstructor().newInstance();5. Using DeserializationObjectInputStream objectInputStream = new ObjectInputStream(inputStream ); Tester tester5 = (MyObject) objectInputStream.readObject(); Using new keyword is the most preferred one.
The following table explains few points about the use of row vs column store tablesTo know more about row and column store tables, refer the below link: SAP HANA is optimized for column storage.https://help.sap.com/doc/6b94445c94ae495c83a19646e7c3fd56/2.0.00/en-US/bd2e9b88bb571014b5b7a628fca2a132.html
To check the Compression ratio for a table, you can navigate to Table Definition. Go to Runtime Information.To see Compression Ratio, go to Columns tab. You can see the compression ratio in the Main Size Compression Ratio [%] column.
Yes, it is similar to a new keyword of C++. a new keyword is used to initialize/create an object. See the following example −Employee employee = new Employee();Here new keyword is used to create an object of class Employee.new Employee() invokes the constructor of the class Employee.new keyword can also be used without assigning the object to a reference variable. See the example −String name = new Employee().getName();Here we are creating an object using new keyword and then invoked a method getName() on the object and passed the result to a variable.
In SAP HANA, there are various methods and algorithms that you can use to store data in Column based structure- Dictionary Compressed, Run Length Compressed and many more.In Dictionary Compressed, cells are stored in form of numbers in tables and numeral cells are always performance optimized as compared to characters.In Run length compressed, it saves the multiplier with cell value in numerical format and multiplier shows repetitive value in the table.Compression is calculated using Compression factor. Compression factor refers to the ratio of the uncompressed data size to the compressed data size in SAP HANA.In SAP HANA, Compression is performed ... Read More
Following the the best practices while declaring a variable. These best practices maintains code readability, understandability as project code size increases.Variables names should be short or long enough as per the scope. For example, loop counter variable, i is fine whereas employee as loop variable.Specific words should not be used like equals, compare, data.Use meaningful names which can explain the purpose of the variable. For example cnt Vs counter.Don't use _ to declare a variable name, Use camel casing. For example, employeeName is better than employee_name.Each organization has its own syntax specific standards. Follow those rules to maintain consistency and ... Read More
In SAP HANA Studio, you can use System Monitor to view details of your SAP HANA system at a glance. It tells about Data Disk, Log disk, Trace Disk, Alerts on resource usage with priority.To open System Monitor, select HANA system in System pane and click on the icon as shown below −Once you scroll on the right side, you can see all the information of your HANA system as you mentioned including CPU% and used memory.