WebApr 17, 2024 · 具体原因:hive-1.2.1 逻辑执行计划优化过程中优化掉了一个SelectOperator操作符,导致数据错位. 在一次为业务方取数的时候,发现查出的数据与自己想象中的不一致,经过各种检查发现sql的逻辑并没有问题,查看执行计划,也没发现明显的问题。. 以自己对 … WebThe primary key (empid) of employee table represents the foreign key (depid) of employee_department table. Let's perform the inner join operation by using the following steps: -. Select the database in which we want to create a table. hive> use hiveql; Now, create a table by using the following command: hive> create table employee (empid int ...
Hive/HiveSQL常用优化方法全面总结 - 腾讯云开发者社区-腾讯云
WebSep 6, 2024 · Built on top of Apache Hadoop™, Hive provides the following features: Tools to enable easy access to data via SQL, thus enabling data warehousing tasks such as extract/transform/load (ETL), reporting, and data analysis. A mechanism to impose structure on a variety of data formats. Access to files stored either directly in Apache HDFS ™ or ... WebAug 17, 2024 · 如果开启了,在join过程中Hive会将计数超过阈值hive.skewjoin.key(默认100000)的倾斜key对应的行临时写进文件中,然后再启动另一个job做map join生成结果。通过hive.skewjoin.mapjoin.map.tasks参数还可以控制第二个job的mapper数量,默认10000。 再重复一遍,通过自带的配置项 ... new zealand shellfish
深度剖析Hive GroupBy,Distinct 与 Join 原理 - 知乎 - 知乎专栏
WebOct 11, 2024 · 2、查看filter_log表strpicdownloadimgmd5个数,6亿左右,做distinct之后,只有5亿。. 大约有1亿重复数据。. 3、如果一个key在user表和filter_log表中都重复出现1k … WebApr 24, 2014 · HiveQL INNER JOIN. I'm trying a simple INNER JOIN between two tables in Hive. I have one table of ORDERS and the other one is a LOG table. This is the structure of both: id_operacion string fecha string id_usuario string id_producto string unidades int id_bono string precio float precio_total float ip string. WebTypes of Joins in Hive. Join- This will give the cross product of both the table’s data as output. As you can see, we have 6 rows in each table. So the output for Join will be 36 rows. The number of mappers-1. However, there no reduce to the operator is used. new zealand scott cheap flights