Creating Hive tables is a common experience to all of us that use Hadoop. Hive keeps adding new clauses to the SHOW PARTITIONS, based on the version you are using the syntax slightly changes. All the commands discussed below will do the same work for SCHEMA and DATABASE keywords in the syntax. Viewing Hive Schema and Table Metadata When using Hive, you access metadata about schemas and tables by executing statements written in HiveQL (Hive's version of SQL) such as SHOW TABLES. Hive facilitates us to drop a table by using the SQL drop table command. SHOW TABLES list/displays tables from the current database. If the FORMATTED keyword is used, then column titles are printed for each column. Their purpose is to facilitate importing of data from an external file into the metastore. As of Hive 0.6, SHOW PARTITIONS can filter the list of partitions as shown below. On this location, you can find the directories for all databases you create and subdirectories with the table name you use. It enables us to mix and merge datasets into unique, customized tables. Partitions are listed in alphabetical order. The SHOW statement is a flexible way to get the information about existing objects in Hive. | dfs.myviews | s3_user_vw | If there is no table specified, the cached metadata for all tables is flushed and synced with Hive Metastore (HMS). Otherwise, hdfs dfs -du -s -h /path/to/table will do. From Hive-0.14.0 release onwards Hive DATABASE is also called as SCHEMA. SHOW CREATE TABLE ([db_name. the “serde”. the “input format” and “output format”. Hive Tables. In this topic, we described about the below sections -. You use familiar insert, update, delete, and merge SQL statements to query table data. | hive.default | orders | Creating Internal Table. As given in above note, Either SCHEMA or DATABASE in Hive is just like a Catalog of tables. The SHOW statement is a flexible way to get the information about existing objects in Hive. Once the table is synced to the Hive metastore, it provides external Hive tables backed by Hudi’s custom inputformats. Show partitions Hive_learning. "Guur99 table" is created in Hive, so the corresponding metadata is stored in MySQL under TBLS. 1) 'show tables;' is the standard SQL way of getting table names. It enables us to mix and merge datasets into unique, customized tables. You also need to define how this table should deserialize the data to rows, or serialize rows to data, i.e. For example, the following USE statement tells Drill that you If no regular expression is given then all tables in the selected database are listed. | dfs.myviews | nestedclickview | Get all the quality content you’ll ever need to stay ahead with a Packt subscription - access over 7,500 online books and videos on everything in tech . |————–|————| 1 row selected (0.412 seconds). See Storage Plugin Optional Arguments. Dec 20, 2020 ; ssh: connect to host localhost port 22: Connection refused in Hadoop. We have some recommended tips for Hive table creation that can increase your query speeds and optimize and reduce the storage space of your tables. Dec 18, 2020 SHOW TABLES is used to show both tables and views. SHOW PARTITIONS lists/displays all the existing partitions for a given base table. Hive facilitates us to drop a table by using the SQL drop table command. The output is order alphabetically by default. This chapter explains how to create Hive database. Use these commands to show table properties in Hive: This command will list all the properties for the Sales table: Copy. Additionally, the output of this statement may be filtered by an optional matching pattern. [code SQL]SHOW CREATE TABLE ; [/code] You'll need to combine this with SHOW TABLES through some kind of script, but shouldn't be more than like 4 lines of code. vi. DESCRIBE and DESCRIBE EXTENDED statements can be used for views like for tables, however, for DESCRIBE EXTENDED, the detailed table information has a variable named typeable which has value = ‘virtual view’ for views. | sys | 1 row selected (0.043 seconds), 0: jdbc:drill:zk=drilldemo:5181> show tables; WHERE, ORDER … 15 rows selected (0.072 seconds). |——|———————————-| Matching tables are listed in alphabetical order. Returns all the tables for an optionally specified database. Their purpose is to facilitate importing of data from an external file into the metastore. | TABLE_SCHEMA | TABLE_NAME | And, there are many ways to do it. This case study describes creation of internal table, loading data in it, creating views, indexes and dropping table on weather data. | dfs.root | IN is an optional keyword in SHOW. Show tblproperties Sales; The preceding command will list only the property for numFiles in the Sales table: Copy. We have some recommended tips for Hive table creation that can increase your query speeds and optimize and reduce the storage space of your tables. |————–|————| Working in Hive and Hadoop is beneficial for manipulating big data. Show partitions Sales ('numFiles'); Show transcript SHOW FUNCTIONS lists/displays all the user defined and builtin functions matching the regular expression. Along with Partitioning on Hive tables bucketing can be done and even without partitioning. |——|—————————————–| ii. Step 9) Checking whether created table … It is a relational database repository that contains metadata about objects we create in hive or externally point to. Consequently, dropping of an external table does not affect the data. | s3.reviews | Let's follow the below steps to drop the table from the database. use ". Most users such as business analysts tend to use SQL and ODBC/JDBC through HiveServer2 and their access can be controlled using this authorization model. Load a table from Hive data. SHOW INDEXES also shows the information like index name, table name, names of the columns used as keys, index table name, index type and comment. The database and schema are interchangeable. Once the proper hudibundle has been installed, the table can be queried by popular query engines like Hive, Spark SQL, Spark Datasource API and PrestoDB. |——|———————————–| | hbase | If this set needs to be customized, the HiveServer2 administrator can set a value for this configuration parameter in its hive-site.xml. SHOW statements provide a way to query/access the Hive metastore for existing data. If no database is specified then the tables are returned from the current database. Hive SHOW PARTITIONS Command. ): SHOW INDEXES shows/displays all of the indexes on the column provided. |——|—————————————–| To enab… Restrictions on Hive Commands and Statements . Registration. Here is the general syntax for truncate table command in Hive – Alter table commands in Hive; With the ALTER command, the structure, metadata or data of the table can be modified quickly with a simple command as shown below in the screenshot. Normally currently users do not use manual locking on Hive tables, because Hive queries themselves will take care of that automatically. The IN clause is used to provide the database if it is not the current. Here's my working code: PROC SQL; CONNECT TO ODBC AS Hive_DB (NOPROMPT = "uid=jbarbour; pwd=XXXXXXXX; dsn=OPSI_HIVE_STG1; host=dbms0502; port=10000;schema=charttarget; authmech=3") ; CREATE TABLE WORK.Hadoop_Table_List AS SELECT * FROM CONNECTION TO Hive_DB(SHOW TABLES); DISCONNECT FROM Hive… |——|———————————–| SHOW TABLES can display tables with names matching the optional regular expression. Viewing Hive Schema and Table Metadata. Let's follow the below steps to drop the table from the database. Moreover, Bucketed tables will create almost equally distributed data file parts. Wildcards can only be '*' for any character(s) or '|' for a choice. When you use a particular schema and then issue the SHOW TABLES command, Drill Show partitions Hive_learning. table_name[.col_name ( [.field_name])]; DDL DESCRIBE TABLE … | TABLE_SCHEMA | TABLE_NAME | |——————–| | true | Default schema changed to ‘hive’ | |————–|—————–| Examples. |————–|—————–| The DESCRIBE statement in Hive shows the lists of columns for the specified table. SHOW INDEXES also shows the information like index name, table name, names of the columns used as keys, index table name, index type and comment. |——————–| The several types of Hive DDL commands are: CREATE; SHOW; DESCRIBE; USE; DROP; ALTER; TRUNCATE; Table-1 Hive DDL commands Database, table … Show Create Table which generates and shows the Create table statement for the given table. This is controlled using the hive.security.authorization.sqlstd.confwhitelistconfiguration parameter. Hive contains a default database named default. tables or views.