Load Data Statements

Load Data Statements #

Description #

The LOAD DATA statement is used to load the data into a Hive table from the user specified directory or file. The load operation are currently pure copy/move operations that move data files into locations corresponding to Hive tables.

Syntax # 

LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)];

Parameters #

  • filepath

    The filepath can be:

    • a relative path, such as warehouse/data1
    • an absolute path, such as /user/hive/warehouse/data1
    • a full URL with schema and (optionally) an authority, such as hdfs://namenode:9000/user/hive/warehouse/data1

    The filepath can refer to a file (in which case, only the single file is loaded) or it can be a directory (in which case, all the files from the directory are loaded).

  • LOCAL

    If specify LOCAL keyword, then:

    • it will look for filepath in the local file system. If a relative path is specified, it will be interpreted relative to the users’ current working directory. The user can specify a full URI for local files as well - for example: file:///user/hive/warehouse/data1
    • it will try to copy all the files addressed by filepath to the target file system. The target file system is inferred by looking at the location attribution. The copied data files will then be moved to the location of the table.

    If not, then:

    • if schema or authority are not specified, it’ll use the schema and authority from the hadoop configuration variable fs.default.name that specifies the NameNode URI.
    • if the path is not absolute, then it’ll be interpreted relative to /user/
    • It will try to move the files addressed by filepath into the table (or partition).

  • OVERWRITE

    By default, the files addressed by filepath will be appended to the table (or partition). If specific OVERWRITE, the original data will be replaced by the files.

  • PARTITION ( ... )

    An option to specify load data into table’s specific partitions. If the PARTITION clause is specified, the table should be a partitioned table.

NOTE:

For loading data into partition, the partition specifications must be full partition specifications. Partial partition specification is not supported yet.

Examples # 

-- load data into table
LOAD DATA LOCAL INPATH '/user/warehouse/hive/t1' OVERWRITE INTO TABLE t1;

-- load data into partition
LOAD DATA LOCAL INPATH '/user/warehouse/hive/t1/p1=1' INTO TABLE t1 PARTITION (p1=1);