#修改分隔符
alter table firstround.person_aaa_crime_criminalperson1 set SERDEPROPERTIES('field.delim'='\001'); 

#檢視建表語句
show CREATE TABLE firstround.banklog_decrypt

#修改欄位型別
ALTER TABLE data_market.last_process_time CHANGE hive_count_num hive_count_num string 

#更改表名
ALTER TABLE transfer_sjdk.bigdata_blacklist RENAME TO transfer_sjdk.tbl_riskprice_it;

#新增表字段
ALTER TABLE transfer_sjdk.bigdata_blacklist_history ADD COLUMNS (is_black string);

#刪除表字段
ALTER TABLE transfer_sjdk.bigdata_blacklist_history drop  is_black;

#清除表資料
TRUNCATE transfer_sjdk.tbl_riskprice_it;

#重新整理表
REFRESH transfer_sjdk.tbl_riskprice_it;

#重新整理表元資料
INVALIDATE METADATA transfer_sjdk.tbl_riskprice_it;

#重新shuffle資料
INSERT OVERWRITE data_market.repayment_split_table SELECT * FROM data_market.repayment_split_table;

#複製表結果和資料
create table transfer_zhifu_real.sy_role as select * from transfer_zhifu.sy_role;

#複製表結構
create table transfer_zhifu_real.sy_role like transfer_zhifu.sy_role;

#修改表名
ALTER TABLE dh_0016_bigdata_08 RENAME TO dh_0016_bigdata

#修改表字段型別
alter TABLE users CHANGE dt dt string

#顯示所有函式
show functions;

#檢視函式用法(hive)
describe function substr;

#匯出查詢結果到檔案
impala-shell -q  "select * from table limit 10" -B --output_delimiter="\t" -o output.txt

#收集表的統計資訊,讓Impala 基於每一個表的大小、每一個列不同值的個數、等等資訊自動的優化查詢。 
compute stats firstround.person_aaa_crime_escapeperson;

#匯入和匯出
export table poc.chan_info to '/user/hive/test/chan_info';
import from '/user/hive/test/chan_info';

#分割槽表匯出和匯入
export table poc.cust_basic_info partition (etl_dt="2017-12-14") to '/user/hive/test/cust_basic_info14';
import from '/user/hive/test/cust_basic_info14';

#import重命名錶
import table cust_basic_info from '/user/hive/test/cust_basic_info14';

#匯出表並且匯入到分割槽表分割槽
import table cust_basic_info partition (etl_dt="2017-12-14") from '/user/hive/test/cust_basic_info';

#指定匯入位置
import table cust_basic_info from '/user/hive/test/cust_basic_info' location '/user/hive/test/cust_basic_info';

#匯入作為一個外部表
import external table cust_basic_info from '/user/hive/test/cust_basic_info';

#強制刪除資料庫
DROP DATABASE  zxfinance_alpha1_tuomin cascade

#資料型別轉換
SELECT cast(substr(createdate,1,10) as int)/86400 created FROM frontlog 

#分組排序
row_number() over (PARTITION BY t4.extractcashbillid,t1.ze_checktime ORDER BY t4.overduedateb DESC) flag 
除Row_number外還有rank,dense_rank  
rank() over([partition by col1] order by col2) 
dense_rank() over([partition by col1] order by col2) 
row_number() over([partition by col1] order by col2)
rank排序時出現相等的值時會有並列，即值相等的兩條資料會有相同的序列值 
row_number的排序不允許並列，即使兩條記錄的值相等也不會出現相等的排序值 
dense_rank排序的值允許並列，但會跳躍的排序，像這樣：1,1,3,4,5,5,7.

#新增udf 方法
impala-shell -q "create function AES(string) returns string location '/user/hive/udf/aesUDF.jar' symbol='com.netease.hive.udf.AESUDF';"

#建立分割槽表
CREATE TABLE IF NOT EXISTS asset_auxiliary.dh_0016_bigdata_history(
autoindex INT, vindicatorteamid STRING,
createtime STRING) 
PARTITIONED BY (dt string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\001'  STORED AS TEXTFILE;
#新增分割槽
alter table asset_auxiliary.dh_0016_bigdata_history add partition (dt='2017-12-12');
#刪除分割槽
ALTER TABLE asset_auxiliary.dh_0016_bigdata_history DROP IF EXISTS PARTITION(dt='2017-12-12');
#載入資料
LOAD DATA INPATH ‘/user/hive/warehouse/asset_auxiliary.db/dh_0016_bigdata_history/2017-12-12/000000_0’ INTO TABLE asset_auxiliary.dh_0016_bigdata_history PARTITION(dt='2017-12-12');
#載入資料到hdfs(hive)
insert overwrite directory '/user/hive/warehouse/asset_auxiliary.db/dh_0016_bigdata_history/dt=2017-12-12'
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\001'
select * from asset_auxiliary.dh_0016_bigdata_tmp where queryday = '2017-12-12'
#載入資料到本地(hive)
insert overwrite local directory '/data/2017-12-12'
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\001'
select * from asset_auxiliary.dh_0016_bigdata_tmp where queryday = '2017-12-12'
#插入資料到表分割槽
insert into table asset_auxiliary.dh_0016_bigdata_history PARTITION(dt='2017-12-10') select * from asset_auxiliary.dh_0016_bigdata_tmp where queryday = '2017-12-10'
#展示表中有多少分割槽
show partitions asset_auxiliary.dh_0016_bigdata_history;
#重新整理分割槽
REFRESH asset_auxiliary.dh_0016_bigdata PARTITION(dt='2017-12-12');
#修復表分割槽 （hive）
msck repair table 表名

#hive 建表
create table test_label.user_json  
( 
   userid string,
   accountid string,
   banknumber string,
   bankname string,
   isreceiveaccount string,
   isrepayaccount string,
   birthday string,
   createtime string
)  
comment '使用者大寬表'
partitioned by(createtime string comment '時間分割槽欄位')  
row format delimited   
fields terminated by '\t'  
stored as textfile  location '/user/hdfs/fico/output/1491964346/user_back_json/';

###impala查詢記憶體限制Memory limit exceeded
ERROR: 
Memory limit exceeded
Query did not have enough memory to get the minimum required buffers in the block manager.

mem_limit=-1
default_pool_mem_limit=-1b

note:https://blog.csdn.net/oosongoo/article/details/78435779