Hive DDL操作例

1. Databases in Hive
   SHOW DATABASES;
   SHOW DATABASES LIKE 'h.*';
   CREATE DATABASE financials;
   CREATE DATABASE IF NOT EXISTS financials;
   CREATE DATABASE financials LOCATION '/my/preferred/directory';
   CREATE DATABASE financials COMMENT 'Holds all financial tables';
   CREATE DATABASE financials WITH DBPROPERTIES ('creator' = 'Mark Moneybags', 'date' = '2012-01-02');
   DESCRIBE DATABASE financials;
   DESCRIBE DATABASE EXTENDED financials;
     Database:
   use financials;
   DROP DATABASE IF EXISTS financials;
   DROP DATABASE IF EXISTS financials CASCADE;
2. Alter Databases
   ALTER DATABASE financials SET DBPROPERTIES ('edited-by' = 'Joe Dba');  
3. Creating Tables
   CREATE TABLE IF NOT EXISTS mydb.employees (
   name STRING COMMENT 'Employee name',
   salary FLOAT COMMENT 'Employee salary',
   subordinates ARRAY COMMENT 'Names of subordinates',
   deductions MAP
   COMMENT 'Keys are deductions names, values are percentages',
   address STRUCT
   COMMENT 'Home address')
   COMMENT 'Description of the table'
   TBLPROPERTIES ('creator'='me', 'created_at'='2012-01-02 10:00:00', ...)
   LOCATION '/user/hive/warehouse/mydb.db/employees';
   
   CREATE TABLE IF NOT EXISTS mydb.employees2 LIKE mydb.employees;
   
   show tblproperties employees;
   SHOW TABLES IN mydb;
   SHOW TABLES 'empl.*';
   
   describe extended employees;
   describe formatted employees;
   
   DESCRIBE mydb.employees.salary;
4. Managed Tables
   CREATE EXTERNAL TABLE IF NOT EXISTS stocks (
   exchange STRING,
   symbol STRING,
   ymd STRING,
   price_open FLOAT,
   price_high FLOAT,
   price_low FLOAT,
   price_close FLOAT,
   volume INT,
   price_adj_close FLOAT)
   ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
   LOCATION '/data/stocks';
   
   CREATE EXTERNAL TABLE IF NOT EXISTS mydb.employees3
   LIKE mydb.employees
   LOCATION '/path/to/data';
5. Partitioned, Managed Tables
   CREATE TABLE employees (
   name STRING,
   salary FLOAT,
   subordinates ARRAY,
   deductions MAP,
   address STRUCT
   )
   PARTITIONED BY (country STRING, state STRING);
   
   SHOW PARTITIONS employees PARTITION(country='US');
   SHOW PARTITIONS employees PARTITION(country='US', state='AK');   
6. Customizing Table Storage Formats
   CREATE TABLE kst
   PARTITIONED BY (ds string)
   ROW FORMAT SERDE 'com.linkedin.haivvreo.AvroSerDe'
   WITH SERDEPROPERTIES ('schema.url'='http://schema_provider/kst.avsc')
   STORED AS
   INPUTFORMAT 'com.linkedin.haivvreo.AvroContainerInputFormat'
   OUTPUTFORMAT 'com.linkedin.haivvreo.AvroContainerOutputFormat';
   
   CREATE EXTERNAL TABLE IF NOT EXISTS stocks (
   exchange STRING,
   symbol STRING,
   ymd STRING,
   price_open FLOAT,
   price_high FLOAT,
   price_low FLOAT,
   price_close FLOAT,
   volume INT,
   price_adj_close FLOAT)
   CLUSTERED BY (exchange, symbol)
   SORTED BY (ymd ASC)
   INTO 96 BUCKETS
   ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
   LOCATION '/data/stocks';
7. Dropping Tables
   DROP TABLE IF EXISTS employees;
8. Alter Table
   ALTER TABLE log_messages RENAME TO logmsgs;
   
   ALTER TABLE log_messages ADD IF NOT EXISTS
   PARTITION (year = 2011, month = 1, day = 1) LOCATION '/logs/2011/01/01'
   PARTITION (year = 2011, month = 1, day = 2) LOCATION '/logs/2011/01/02'
   PARTITION (year = 2011, month = 1, day = 3) LOCATION '/logs/2011/01/03'
   ...;
   
   ALTER TABLE log_messages PARTITION(year = 2011, month = 12, day = 2)
   SET LOCATION 's3n://ourbucket/logs/2011/01/02';
   
   ALTER TABLE log_messages DROP IF EXISTS PARTITION(year = 2011, month = 12, day = 2);
   
   ALTER TABLE log_messages
   CHANGE COLUMN hms hours_minutes_seconds INT
   COMMENT 'The hours, minutes, and seconds part of the timestamp'
   AFTER severity;
   
   ALTER TABLE log_messages ADD COLUMNS (
   app_name STRING COMMENT 'Application name',
   session_id LONG COMMENT 'The current session id');
   
   ALTER TABLE log_messages REPLACE COLUMNS (
   hours_mins_secs INT COMMENT 'hour, minute, seconds from timestamp',
   severity STRING COMMENT 'The message severity'
   message STRING COMMENT 'The rest of the message');
   
   ALTER TABLE log_messages SET TBLPROPERTIES ('notes' = 'The process id is 
   no longer captured; this column is always NULL');
   
   ALTER TABLE log_messages
   PARTITION(year = 2012, month = 1, day = 1)
   SET FILEFORMAT SEQUENCEFILE;
   
   ALTER TABLE table_using_JSON_storage
   SET SERDE 'com.example.JSONSerDe'
   WITH SERDEPROPERTIES (
   'prop1' = 'value1',
   'prop2' = 'value2');
   
   ALTER TABLE stocks
   CLUSTERED BY (exchange, symbol)
   SORTED BY (symbol)
   INTO 48 BUCKETS;
   
   ALTER TABLE log_messages TOUCH PARTITION(year = 2012, month = 1, day = 1);
   ALTER TABLE log_messages ARCHIVE PARTITION(year = 2012, month = 1, day = 1);
   
   ALTER TABLE log_messages PARTITION(year = 2012, month = 1, day = 1) ENABLE NO_DROP;
   ALTER TABLE log_messages PARTITION(year = 2012, month = 1, day = 1) ENABLE OFFLINE;