Hive notes

hive sample test

CREATE TABLE words ( word string);
LOAD DATA LOCAL INPATH \'/usr/share/dict/words\' OVERWRITE INTO TABLE words;
SELECT * FROM words WHERE word LIKE \'%hello%\';
DROP TABLE words ;

Rename the table to hive

ALTER TABLE table_name RENAME TO new_table_name;

Check the partition table

SHOW PARTITIONS table_name;

View Hive built-in functions

show functions;

View Hive function of the specific use

desc function extended function name ; eg.desc function extended trim;

Set mapreduce memory size

set mapred.child.java.opts=-Xmx2048m;

Set output without compression

set hive.exec.compress.output=false;

hive using a derby db as metestore time, specify the database location. Add the following to the hive-site.xml in:

<property>
    <name>javax.jdo.option.ConnectionURL</name>
    <value>jdbc:derby:;databaseName=/home/leileisyh/metastore_db;create=true</value>
</property>

When this hive for the log This is normal. Try local mode failed. Backup to distributed mode. Please add the following configuration at the hive-site.xml, the mandatory use of distributed mode

<property>
    <name>hive.exec.mode.local.auto</name>
    <value>false</value>
    <description> Let hive determine whether to run in local mode automatically </description>
</property>

View table structure (which can be found in specific HDFS path hive table)

desc formatted table name