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· 7 min read

A detailed blog post

already explains the ins and outs of why Scala users can now use the Flink Java API with any Scala version (including Scala 3).

In the end, removing Scala is just part of a larger effort of cleaning up and updating various technologies from the Flink ecosystem.

· 5 min read

准备表和数据

show full builtin  functions in test_db like 'year';
CREATE TABLE table1 
(
siteid INT DEFAULT '10', 
citycode SMALLINT,
username VARCHAR(32) DEFAULT '', 
pv BIGINT SUM DEFAULT '0'
)
AGGREGATE KEY(siteid, citycode, username) 
DISTRIBUTED BY HASH(siteid) BUCKETS 10 
PROPERTIES("replication_num" = "1");
insert into table1 values 
(1,1,'jim',2),
(2,1,'grace',2), 
(3,2,'tom',2),
(4,3,'bush',3), 
(5,3,'helen',3);

· One min read

Hbase 存储和查询维度数据

  • Hbase 数据分析效率低 分析函数少，Hbase数据分析涉及磁盘读取数据，比较版本，聚合导致效率低下

ClickHouse 存储和查询宽表数据

  • 更擅长数据分析而不是查询明细，维度数据不宜存放 ClickHouse