THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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- assign 'aggregation' to 'merge-engine'
- designate aggregate function for each column of table.
For example,
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-
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-
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DDL
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CREATE
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TABLE
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T
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(
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...
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pk
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STRING
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PRIMARY
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KEY
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NOT
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ENFOCED,
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...
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sum_field1
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BIGINT,
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max_field1
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BIGINT
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)
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WITH
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(
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'merge-engine'
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=
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'aggregation',
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'fields.sum_field1.function'='sum',
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-
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-
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sum
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up
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all
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sum_field1
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with
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same
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pk;
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'fields.max_field1.function'='max'
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-
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-
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get
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max
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value
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of
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all
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max_field1
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with
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same
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pk
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);
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– DML
INSERT INTO T VALUES ('pk1',
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1,
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2);
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INSERT
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INTO
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T
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VALUES
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('pk1',
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1,
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1);
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– verify
SELECT * FROM T;
=> output 'pk1',
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2,
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2
Tips: each column should be designated aggregate functions.
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