I needed to create huge test data in hive table. I tried following commands but it only inserts one partition data at a time.
connect to beeline:
beeline --force=true -u 'jdbc:hive2://<host>:<port>/<hive database name>;ssl=true;user=<username>;password=<pw>'
create partitioned table :
CREATE TABLE p101(
Name string,
Age string)
PARTITIONED BY(fi string)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ',';
I have created ins.csv file with data and copy it to hdfs location, its data is as follows.
Name,Age
aaa,33
bbb,22
ccc,55
then I tried to load same file for multiple partition ids with following command
LOAD DATA INPATH 'hdfs_path/ins.csv' INTO TABLE p101 PARTITION(fi=1,fi=2,fi=3,fi=4,fi=5);
but it loads record only for partitionID=5.
You can only specify one partition for each insert into.
What you can do in order to have different partitions is add it into your csv file like this:
Name,Age,fi
aaa,33,1
bbb,22,2
ccc,55,3
Hive will automatically know that this is the partition.
LOAD DATA INPATH 'hdfs_path/ins.csv' INTO TABLE tmp.p101;
I'm trying to generate some parquet files with hive,to accomplish this i loaded a regular hive table from some .tbl files, throuh this command in hive:
CREATE TABLE REGION (
R_REGIONKEY BIGINT,
R_NAME STRING,
R_COMMENT STRING)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '|'
STORED AS TEXTFILE
location '/tmp/tpch-generate';
After this i just execute this 2 lines:
create table parquet_reion LIKE region STORED AS PARQUET;
insert into parquet_region select * from region;
But when i check the output generated in HDFS, i dont find any .parquet file, intead i find files names like 0000_0 to 0000_21, and the sum of their sizes are much bigger that the original tbl file.
What im i doing Wrong?
Insert statement doesn't create file with extension but these are the parquet files.
You can use DESCRIBE FORMATTED <table> to show table information.
hive> DESCRIBE FORMATTED <table_name>
Additional Note: You can also create new table from source table using below query:
CREATE TABLE new_test row STORED AS PARQUET AS select * from source_table
It will create new table as parquet format and copies the structure as well as the data.
I have a map reduce job, that already writes out record to hdfs using hive partition naming convention.
eg
/user/test/generated/code=1/channel=A
/user/test/generated/code=1/channel=B
After I create an external table, it does not see the partition.
create external table test_1 ( id string, name string ) partitioned by
(code string, channel string) STORED AS PARQUET LOCATION
'/user/test/generated'
Even with the alter command
alter table test_1 ADD PARTITION (code = '1', channel = 'A')
, it does not see the partition or record,
because
select * from test_1 limit 1 produces 0 result.
If I use empty location when I create external table, and then use
load data inpath ...
then it works. But the issue is there is too many partitions for the load data inpath to work.
Is there a way to make hive recognize the partition automatically (without doing insert query)?
Using msck, it seems to be working. But I had to exit the hive session, and connect again.
MSCK REPAIR TABLE test_1
I am new to hive. I have successfully setup a single node hadoop cluster for development purpose and on top of it, I have installed hive and pig.
I created a dummy table in hive:
create table foo (id int, name string);
Now, I want to insert data into this table. Can I add data just like sql one record at a time? kindly help me with an analogous command to:
insert into foo (id, name) VALUES (12,"xyz);
Also, I have a csv file which contains data in the format:
1,name1
2,name2
..
..
..
1000,name1000
How can I load this data into the dummy table?
I think the best way is:
a) Copy data into HDFS (if it is not already there)
b) Create external table over your CSV like this
CREATE EXTERNAL TABLE TableName (id int, name string)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ','
LINES TERMINATED BY '\n'
STORED AS TEXTFILE
LOCATION 'place in HDFS';
c) You can start using TableName already by issuing queries to it.
d) if you want to insert data into other Hive table:
insert overwrite table finalTable select * from table name;
There's no direct way to insert 1 record at a time from the terminal, however, here's an easy straight forward workaround which I usually use when I want to test something:
Assuming that t is a table with at least 1 record. It doesn't matter what is the type or number of columns.
INSERT INTO TABLE foo
SELECT '12', 'xyz'
FROM t
LIMIT 1;
Hive apparently supports INSERT...VALUES starting in Hive 0.14.
Please see the section 'Inserting into tables from SQL' at: https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DML
What ever data you have inserted into one text file or log file that can put on one path in hdfs and then write a query as follows in hive
hive>load data inpath<<specify inputpath>> into table <<tablename>>;
EXAMPLE:
hive>create table foo (id int, name string)
row format delimited
fields terminated by '\t' or '|'or ','
stored as text file;
table created..
DATA INSERTION::
hive>load data inpath '/home/hive/foodata.log' into table foo;
to insert ad-hoc value like (12,"xyz), do this:
insert into table foo select * from (select 12,"xyz")a;
this is supported from version hive 0.14
INSERT INTO TABLE pd_temp(dept,make,cost,id,asmb_city,asmb_ct,retail) VALUES('production','thailand',10,99202,'northcarolina','usa',20)
It's a limitation of hive.
1.You cannot update data after it is inserted
2.There is no "insert into table values ... " statement
3.You can only load data using bulk load
4.There is not "delete from " command
5.You can only do bulk delete
But you still want to insert record from hive console than you can do select from statck. refer this
You may try this, I have developed a tool to generate hive scripts from a csv file. Following are few examples on how files are generated.
Tool -- https://sourceforge.net/projects/csvtohive/?source=directory
Select a CSV file using Browse and set hadoop root directory ex: /user/bigdataproject/
Tool Generates Hadoop script with all csv files and following is a sample of
generated Hadoop script to insert csv into Hadoop
#!/bin/bash -v
hadoop fs -put ./AllstarFull.csv /user/bigdataproject/AllstarFull.csv
hive -f ./AllstarFull.hive
hadoop fs -put ./Appearances.csv /user/bigdataproject/Appearances.csv
hive -f ./Appearances.hive
hadoop fs -put ./AwardsManagers.csv /user/bigdataproject/AwardsManagers.csv
hive -f ./AwardsManagers.hive
Sample of generated Hive scripts
CREATE DATABASE IF NOT EXISTS lahman;
USE lahman;
CREATE TABLE AllstarFull (playerID string,yearID string,gameNum string,gameID string,teamID string,lgID string,GP string,startingPos string) row format delimited fields terminated by ',' stored as textfile;
LOAD DATA INPATH '/user/bigdataproject/AllstarFull.csv' OVERWRITE INTO TABLE AllstarFull;
SELECT * FROM AllstarFull;
Thanks
Vijay
You can use following lines of code to insert values into an already existing table. Here the table is db_name.table_name having two columns, and I am inserting 'All','done' as a row in the table.
insert into table db_name.table_name
select 'ALL','Done';
Hope this was helpful.
Hadoop file system does not support appending data to the existing files. Although, you can load your CSV file into HDFS and tell Hive to treat it as an external table.
Use this -
create table dummy_table_name as select * from source_table_name;
This will create the new table with existing data available on source_table_name.
LOAD DATA [LOCAL] INPATH '' [OVERWRITE] INTO TABLE <table_name>;
use this command it will load the data at once just specify the file path
if file is in local fs then use LOCAL if file is in hdfs then no need to use local
I've created a Hive Table through an Elastic MapReduce interactive session and populated it from a CSV file like this:
CREATE TABLE csvimport(id BIGINT, time STRING, log STRING)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t';
LOAD DATA LOCAL INPATH '/home/hadoop/file.csv' OVERWRITE INTO TABLE csvimport;
I now want to store the Hive table in a S3 bucket so the table is preserved once I terminate the MapReduce instance.
Does anyone know how to do this?
Yes you have to export and import your data at the start and end of your hive session
To do this you need to create a table that is mapped onto S3 bucket and directory
CREATE TABLE csvexport (
id BIGINT, time STRING, log STRING
)
row format delimited fields terminated by ','
lines terminated by '\n'
STORED AS TEXTFILE
LOCATION 's3n://bucket/directory/';
Insert data into s3 table and when the insert is complete the directory will have a csv file
INSERT OVERWRITE TABLE csvexport
select id, time, log
from csvimport;
Your table is now preserved and when you create a new hive instance you can reimport your data
Your table can be stored in a few different formats depending on where you want to use it.
Above Query needs to use EXTERNAL keyword, i.e:
CREATE EXTERNAL TABLE csvexport ( id BIGINT, time STRING, log STRING )
row format delimited fields terminated by ',' lines terminated by '\n'
STORED AS TEXTFILE LOCATION 's3n://bucket/directory/';
INSERT OVERWRITE TABLE csvexport select id, time, log from csvimport;
An another alternative is to use the query
INSERT OVERWRITE DIRECTORY 's3n://bucket/directory/' select id, time, log from csvimport;
the table is stored in the S3 directory with HIVE default delimiters.
If you could access aws console and have the "Access Key Id" and "Secret Access Key" for your account
You can try this too..
CREATE TABLE csvexport(id BIGINT, time STRING, log STRING)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t'
LOCATION 's3n://"access id":"secret key"#bucket/folder/path';
Now insert the data as other stated above..
INSERT OVERWRITE TABLE csvexport select id, time, log from csvimport;