hbase structure

table is made up of rows and columns. Columns are divided into a number of column families (row family).Comparison of 1.2 HBase with traditional databaseWe can first look at the tables in the traditional relational database:Then, comparing with HBase's table, HBase's table structure differs greatly from the traditional relational database.We can find many different places:HBase does not support SQL stateme

tables (except the-root table and the. Meta table (filtered out) can be listed by listHBase (main) > list2) Create the table, where T1 is the table name, F1, F2 is the column family of T1. Tables in HBase have at least one column family. Among them, the column families directly affect the physical characteristics of the HBase data store.# syntax:create # example: Create TABLE T1, with two family NAME:F1,F2

HBase cannot connect to ZooKeeper. hbase connects to zookeeper. The following error is reported when you log on to the server after setting up the HBase Environment last time: Hadoop @ gpmaster logs] $ hbase shellSLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar: file:/home/hadoop/

3.describe: View table structure description Usage: Describe ' product ' 4.Alter: Modify the table Usage: Modify table structure must first disable, then modify the table, after the modification, then the Enable table. Disable ' product ' Alter ' product ', {NAME => ' food ',versions=> 3} Enable ' product ' 5.Drop: Delete table Usage: First disable, then drop. Disable ' product ' Drop ' product ' 1.

fileinfo. As shown in the middle, the trailer has a pointer to the starting point of other data blocks. File info records the meta information of the file, such as avg_key_len, avg_value_len, last_key, comparator, and max_seq_id_key. The data index and meta index blocks record the starting point of each data block and meta block. Data block is the basic unit of hbase I/O. To improve efficiency, hregionserver has a LRU-based block cache mechanism. The

Tags: SQL HBA is INF environment Region system input CustomerWelcome to the big Data and AI technical articles released by the public number: Qing Research Academy, where you can learn the night white (author's pen name) carefully organized notes, let us make a little progress every day, so that excellent become a habit! I. The basic concept of HBase: A column-based database In the Hadoop ecosystem, HBase i

, Max_seq_id_key, and so on. The data index and Meta index blocks record the starting point for each data block and meta block.The Data block is the basic unit of HBase I/O, and in order to improve efficiency, the hregionserver is based on the LRU block cache mechanism. The size of each data block can be specified by parameters when creating a table, the large block facilitates sequential scan, and the small block is useful for random queries. Each da

. The Reduce function does not need to be considered and is provided by HBase. This job uses rowkey (row Key) as the output Key, KeyValue, Put, or Delete as the output Value. MapReduce jobs need to use HFileOutputFormat2 to generate HBase data files. To effectively import data, you need to configure HFileOutputFormat2 so that each output file is in a suitable region. To achieve this purpose, MapReduce jobs

HBase is an open-source, scalable, distributed NoSQL database for massive data storage that is modeled on the Google BigTable data model and built on the HDFs storage system of Hadoop. It differs significantly from the relational database MySQL, Oracle, etc., and HBase's data model sacrifices some of the features of the relational database, but in exchange for great scalability and flexible operation of the table