페이지 이력

...

코드 블럭

language	text
linenumbers	true

> SELECT COUNT(*) AS 'rows', COUNT(tail_num) AS 'non-null tail numbers'
  FROM airlines_external;
+-----------+-----------------------+
| rows      | non-null tail numbers |
+-----------+-----------------------+
| 123534969 | 412968                |
+-----------+-----------------------+

> WITH t1 AS
  (SELECT COUNT(*) AS 'rows', COUNT(tail_num) AS 'nonnull'
  FROM airlines_external)
SELECT `rows`, `nonnull`, `rows` - `nonnull` AS 'nulls',
  (`nonnull` / `rows`) * 100 AS 'percentage non-null'
FROM t1;
+-----------+---------+-----------+---------------------+
| rows      | nonnull | nulls     | percentage non-null |
+-----------+---------+-----------+---------------------+
| 123534969 | 412968  | 123122001 | 0.3342923897119365  |
+-----------+---------+-----------+---------------------+

테이블의 CREATE 문 확인하기

코드 블럭

language	text
linenumbers	true

> SHOW CREATE TABLE airlines_external;
"CREATE EXTERNAL TABLE airlines_data.airlines_external (
  year INT COMMENT 'inferred from: optional int32 year',
  month INT COMMENT 'inferred from: optional int32 month',
  day INT COMMENT 'inferred from: optional int32 day',
  dayofweek INT COMMENT 'inferred from: optional int32 dayofweek',
  dep_time INT COMMENT 'inferred from: optional int32 dep_time',
  crs_dep_time INT COMMENT 'inferred from: optional int32 crs_dep_time',
  arr_time INT COMMENT 'inferred from: optional int32 arr_time',
  crs_arr_time INT COMMENT 'inferred from: optional int32 crs_arr_time',
  carrier STRING COMMENT 'inferred from: optional binary carrier',
  flight_num INT COMMENT 'inferred from: optional int32 flight_num',
  tail_num INT COMMENT 'inferred from: optional int32 tail_num',
  actual_elapsed_time INT COMMENT 'inferred from: optional int32 actual_elapsed_time',
  crs_elapsed_time INT COMMENT 'inferred from: optional int32 crs_elapsed_time',
  airtime INT COMMENT 'inferred from: optional int32 airtime',
  arrdelay INT COMMENT 'inferred from: optional int32 arrdelay',
  depdelay INT COMMENT 'inferred from: optional int32 depdelay',
  origin STRING COMMENT 'inferred from: optional binary origin',
  dest STRING COMMENT 'inferred from: optional binary dest',
  distance INT COMMENT 'inferred from: optional int32 distance',
  taxi_in INT COMMENT 'inferred from: optional int32 taxi_in',
  taxi_out INT COMMENT 'inferred from: optional int32 taxi_out',
  cancelled INT COMMENT 'inferred from: optional int32 cancelled',
  cancellation_code STRING COMMENT 'inferred from: optional binary cancellation_code',
  diverted INT COMMENT 'inferred from: optional int32 diverted',
  carrier_delay INT COMMENT 'inferred from: optional int32 carrier_delay',
  weather_delay INT COMMENT 'inferred from: optional int32 weather_delay',
  nas_delay INT COMMENT 'inferred from: optional int32 nas_delay',
  security_delay INT COMMENT 'inferred from: optional int32 security_delay',
  late_aircraft_delay INT COMMENT 'inferred from: optional int32 late_aircraft_delay'
)
STORED AS PARQUET
LOCATION 'hdfs://a1730.example.com:8020/user/impala/staging/airlines'
TBLPROPERTIES ('numFiles'='0', 'COLUMN_STATS_ACCURATE'='false',
  'transient_lastDdlTime'='1439425228', 'numRows'='-1', 'totalSize'='0',
  'rawDataSize'='-1')"

...

페이지 트리

버전 비교

이전 버전 5

새 버전 6

키

테이블의 CREATE 문 확인하기