Tag Archives: hive

Before this, the Hive should be correctly installed. This not only means that you can enter hive, but also your hive can interact with the mysql you configured. 1. Jars needed. It’s better you import all .jar files in /Hive/lib. Besides, you need hadoop-common-2.3.0.jar and slf4j-api-1.6.6.jar.Include them: activation-1.1.jar ant-1.9.1.jar ant-launcher-1.9.1.jar antlr-2.7.7.jar antlr-runtime-3.4.jar asm-commons-3.1.jar asm-tree-3.1.jar avro-1.7.5.jar… Read More »

hive.mapred.mode=strict mode By default, “order by” will transfer to only one reducer. If the data amount is huge, it may exhuast the resource of the only reducer. So, it is suggested to use “limit” keyword to limit the output amount. When hive.mapred.mode=strict is set, hive will force to use “limit” when “order by” is used. Or… Read More »

Where select * from partition_table where dt=’2014-04-01′ and dep=’R&D’; Limit. This can’t be used like “limit 1,3”; select * from partition_table where dt=’2014-04-01′ and dep=’R&D’ limit 5; “select *”, and the partition fields after where. They don’t require MapReduce, which improve the query efficiency. For example, salary is not a partition field, so this select requires… Read More »

Create an internal table: create table hive_1_1(id string, name string, gender string) row format delimited fields terminated by ‘,’ stored as textfile; Create an out table: create external table hive_1_1(id string, name string, gender string) row format delimited fields terminated by ‘,’ stored as textfile; Load data from local computer: load data local inpath ‘/home/hadoop/hive-0.13.1/student.txt’… Read More »