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Cloudera CDH/CDP 및 Hadoop EcoSystem, Semantic IoT등의 개발/운영 기술을 정리합니다. gooper@gooper.com로 문의 주세요.


hive Hive Query Examples from test code (2 of 2)

총관리자 2014.03.26 11:06 조회 수 : 11565

Hive query for adding jar or script files

set jar=${system:build.ivy.lib.dir}/default/derby-${system:derby.version}.jar;

add file ${hiveconf:jar}; -- 추가
list file;  -- 리스트
delete file ${hiveconf:jar}; -- 삭제


Hive example for creating table using RegexSerDe

CREATE TABLE serde_regex(
  host STRING,
  identity STRING,
  user STRING,
  time STRING,
  request STRING,
  status STRING,
  size STRING,
  referer STRING,
  agent STRING)
ROW FORMAT SERDE 'org.apache.hadoop.hive.contrib.serde2.RegexSerDe'
WITH SERDEPROPERTIES (
  "input.regex" = "([^ ]*) ([^ ]*) ([^ ]*) (-|\[[^\]]*\]) ([^ "]*|"[^"]*") (-|[0-9]*) (-|[0-9]*)(?: ([^ "]*|"[^"]*") ([^ "]*|"[^"]*"))?",
  "output.format.string" = "%1$s %2$s %3$s %4$s %5$s %6$s %7$s %8$s %9$s"
)
STORED AS TEXTFILE;

아파치 로그 파일

../data/files/apache.access.log

127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326

아파치 로그 파일2

../data/files/apache.access.2.log

127.0.0.1 - - [26/May/2009:00:00:00 +0000] "GET /someurl/?track=Blabla(Main) HTTP/1.1" 200 5864 - "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/525.19 (KHTML, like Gecko) Chrome/1.0.154.65 Safari/525.19"


Hive query which contains “transform” using specific script.

set hive.input.format=org.apache.hadoop.hive.ql.io.HiveInputFormat;
CREATE TABLE dest1(key INT, value STRING);

ADD FILE src/test/scripts/testgrep;

FROM (
  FROM src
  SELECT TRANSFORM(src.key, src.value)
         USING 'testgrep' AS (tkey, tvalue)
  CLUSTER BY tkey
) tmap
INSERT OVERWRITE TABLE dest1 SELECT tmap.tkey, tmap.tvalue;

SELECT dest1.* FROM dest1;

src/test/scripts/testgrep

#!/bin/bash
egrep '10.*'

exit 0;


Hive tablesamples example

https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Sampling

-- TABLESAMPLES
CREATE TABLE bucketized_src (key INT, value STRING)
CLUSTERED BY (key) SORTED BY (key) INTO 1 BUCKETS;

INSERT OVERWRITE TABLE bucketized_src
SELECT key, value FROM src WHERE key=66;

SELECT key FROM bucketized_src TABLESAMPLE(BUCKET 1 out of 1);


Hive query for creating table using specific delimiters

create table impressions (imp string, msg string)
row format delimited
fields terminated by 't'
lines terminated by 'n'
stored as textfile;


기본 파티션 이름 설정

create table default_partition_name (key int, value string) partitioned by (ds string);

set hive.exec.default.partition.name='some_other_default_partition_name';

alter table default_partition_name add partition(ds='__HIVE_DEFAULT_PARTITION__');

show partitions default_partition_name;


문자열 상수 처리

SELECT 'face''book', 'face' 'book', 'face'
                                'book',
   "face""book", "face" "book", "face"
                                "book",
   'face' 'bo' 'ok', 'face'"book",
   "face"'book', 'facebook' FROM src LIMIT 1;

결과

facebook    facebook    facebook    facebook    facebook    facebook    facebook    facebook    facebook    facebook


Hive table lock examples

CREATE TABLE tstsrc (col1 STRING) STORED AS TEXTFILE;

SHOW LOCKS;
SHOW LOCKS tstsrc;
SHOW LOCKS tstsrc extended;

LOCK TABLE tstsrc shared;
UNLOCK TABLE tstsrc;


Hive partition lock examples

LOCK TABLE tstsrcpart PARTITION(ds='2008-04-08', hr='11') EXCLUSIVE;

SHOW LOCKS tstsrcpart PARTITION(ds='2008-04-08', hr='11') extended;

UNLOCK TABLE tstsrcpart PARTITION(ds='2008-04-08', hr='11');  


Hive virtual column

0.8.0 부터 INPUT_FILENAME, BLOCKOFFSETINSIDE_FILE 두 개 가상 컬럼 지원함

  • INPUT_FILE_NAME는 맵퍼 테스크의 파일 이름
  • BLOCK_OFFSETINSIDE_FILE는 현재 글로벌 파일 포지션

블락이 압축된 파일인 경운 현재 블락의 파일 오프셋은 현재 블락의 첫번째 바이트의 파일 오프셋이다.

select INPUT__FILE__NAME, key, BLOCK__OFFSET__INSIDE__FILE from src;


로컬 디렉토리에 결과 쓰기

FROM src INSERT OVERWRITE DIRECTORY '../build/contrib/hive/ql/test/data/warehouse/dest4.out' SELECT src.value WHERE src.key >= 300

dfs -cat ../build/contrib/hive/ql/test/data/warehouse/dest4.out/*;


Hive example for comparison of timestamp values

select cast('2011-05-06 07:08:09' as timestamp) > 
  cast('2011-05-06 07:08:09' as timestamp) from src limit 1;


Hive type casting

SELECT IF(false, 1, cast(2 as smallint)) + 3 FROM src LIMIT 1;


Show table properties in Hive

show tblproperties tmpfoo;
show tblproperties tmpfoo("bar");


Display functions in Hive CLI

SHOW FUNCTIONS;

SHOW FUNCTIONS '^c.*';

SHOW FUNCTIONS '.*e$';

SHOW FUNCTIONS 'log.*';

SHOW FUNCTIONS '.*date.*';

SHOW FUNCTIONS '***';


Show colums in Hive

CREATE TABLE shcol_test(KEY STRING, VALUE STRING) PARTITIONED BY(ds STRING) STORED AS TEXTFILE;

SHOW COLUMNS from shcol_test;


Reset hive settings

set hive.skewjoin.key;
set hive.skewjoin.mapjoin.min.split;
set hive.skewjoin.key=300000;
set hive.skewjoin.mapjoin.min.split=256000000;
set hive.skewjoin.key;
set hive.skewjoin.mapjoin.min.split;

reset;

set hive.skewjoin.key;
set hive.skewjoin.mapjoin.min.split;


Print column header in Hive CLI

set hive.cli.print.header=true;


프로그래스 heartbeat 간격

set hive.heartbeat.interval=5; 


DDL 관련 출력 포맷을 json으로 변경

set hive.ddl.output.format=json;

desc extended table_name;

set hive.ddl.output.format=text; -- 기본값
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