What is hbase?
Hbase is a sub-project in Apache hadoop. hbase relies on hadoop's HDFS as the basic storage unit. By using hadoop's DFS tool, you can see the structure of these data storage folders, you can also use the MAP/reduce framework (Algorithm) Perform operations on hbase, as shown in the figure on the right:
Hbase also includes jetty in the product and uses embedded methods to start jetty during hbase startup. Therefore, you can manage hbase on the web interface and view the current running status, very lightweight.
Why?Hbase?
Hbase is a database suitable for storing unstructured data, unlike general relational databases. the so-called unstructured data storage means that hbase is based on columns rather than the row-based mode. In this way, you can read and write your big data content.
Hbase is a data storage method between map entry (Key & value) and DB row. This is a bit similar to the popular memcache, but it is not just a simple key that corresponds to a value. You may need to store the data structure of multiple attributes, however, there are not so many associations in traditional database tables. This is called loose data.
Simply put, you can create a table in hbase as a large table, and the attributes of this table can be dynamically increased as needed, there is no association query between tables in hbase. You only need to tell your data to the column families stored in hbase. You do not need to specify its specific types: Char, varchar, Int, tinyint, text, and so on. However, you must note that hbase does not include the functions of transactions.
Apache hbase is very similar to Google bigtable. A data row has an selectable key and any number of columns. Tables are loosely stored. Therefore, you can define different columns for rows. This feature is very useful for large projects and simplifies the design and upgrade costs.