Key type of validation class in cassadra UTF8 or LongType?

Question

I am new to cassandra and I want to save 20 million + row rows in a column family.

my question

1. Is there a REAL performance difference between long and utf8 rowKey keys?

2.any problem with row storage size?

my userkey looks like this

rowKey=>112512462152451
rowKey=>135431354354343
rowKey=>145646546546463
rowKey=>154354354354354
rowKey=>156454343435435
rowKey=>154435435435745

early

Answer 1

• Cassandra ( ) . , . , , , / . , Long - (), UTF8 (ascii-betical).

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Datastax .

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Answer 2

• .
• , , . , , , , . .

Cassandra 1.1 , :

https://git-wip-us.apache.org/repos/asf?p=cassandra.git;a=blob;f=src/java/org/apache/cassandra/service/CacheService.java;hb=02672936#l102

48 , . - , , , , cassandra.yaml. Cassandra 1.2.

32 , .