Hive

Question 1

What is the coding format for creating a table?

Answer 1

Create table table_name (id int, name STRING, ssn BIGINT)

ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘ ‘ LINES BY ‘\n’

Same way you create on in SQL: “create name” followed by the column (aka fields names of the table) separated via comma).

Question 2

what is the coding format to make an external table?

Answer 2

CREATE EXTERNAL TABLE /table name e.g./ ugenre_external_table (
genre INT, # the datatype name
genreID TINYINT)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘|’ LINES TERMINATED BY ‘\n’;

Question 3

what is the coding format to LOAD a table?

Answer 3

LOAD DATA INPATH ‘ ‘’ ‘ ‘’ OVERWRITE INTO TABLE ‘ ‘’ ‘ ‘’ ;

LOAD DATA INPATH ‘/user/maria_dev/u.data’ OVERWRITE INTO TABLE udata_external_table;

Question 4

what it he code for the constraints on a table for a json file separated by commas

Answer 4

ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘,’ LINES TERMINATED BY ‘\n’

Question 5

What is the syntax to create a table, and at the same time populate the code with data from another column

Answer 5

create table {table name} AS SELECT

create table salary_internal as select salary_id,employee_id,payment,datefrom salary;

Question 6

to find data on a file

Answer 6

describe formatted {table_name}

Question 7

What is the syntax to alter a partition from a static partition to a dynamic partition

Answer 7

SET hive.exec.dynamic.partition=true;

SET hive.exec.dynamic.partition.mode=nonstrict;

Question 8

How (i.e. what is the syntax) and where do you format a compression file.

Answer 8

When you create your table:

create table employee_par
(salary_id TINYINT, employee_id TINYINT, payment FLOAT, the_date STRING)
stored as parquetfile;

Question 9

What are the different compatible formats within Hadoop

Answer 9

• ORC
• AVRO
• JSON
• Parquet
• Sequence
• txt files (i.e. CSV)