Oracle Unique Key
Hive Unique Key Generator Randomuuid Generator

Jul 19, 2017 hive select fname,ip,ROWNUMBER OVER (ORDER BY ip ) as rownum from sales; RANK: It is similar to ROWNUMBER, but the equal rows are ranked with the same number. For example, if we use RANK in the previous query instead of ROWNUM. If Java 5 is not available, then there are other more laborious ways to generate unique ids (see below). Style 2 - SecureRandom and MessageDigest. The following method uses SecureRandom and MessageDigest: upon startup, initialize SecureRandom (this may be a lengthy operation) when a new identifier is needed, generate a random number using SecureRandom. Apr 20, 2006 How to Generate Sequences and Surrogate Keys in Generic SQL Published Apr 20, 2006. Database designers sometimes introduce a surrogate key, which uniquely identifies every row in the table and is “more minimal” than the inherently unique aspect of the data. The usual choice is a monotonically increasing integer, which is small.

UUID / GUID (Universally / Globally Unique Identifier) is frequently use in programming. Some of its usage are for creating random file names, session id in web application, transaction id and for record’s primary keys in database replacing the sequence or auto generated number.

To generate UUID in Java we can use the java.util.UUID class. This class was introduced in JDK 1.5. The UUID.randomUUID() method return a UUID object. To obtain the value of the random string generated we need to call the UUID.toString() method.

We can also get the version and the variant of the UUID using the version() method and variant() method respectively. Let’s see the code snippet below:

UUID/GUID comes from the acronym Universally/Globally Unique Identifier, which is a 128-bit number used to identify information in computer systems. You can check the sourcecode for the project at: Front-End (Gatsby static site).
For Hive to replace a modern datawarehouse based on RDBMS, it must have support for keys, constraints, auto-increment values, surrogate keys and not null features etc. Many customers do not move their EDW to Hive due to these reasons as these have been challenging to maintain in Hive.

Oracle Unique Key

The result of our program is:

Hive Unique Key Generator Randomuuid Generator

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