good first issuetype/feature-request
描述
Description
Sometimes we want to export complex(hll/bitmap/quantile_state/agg_state) types for data backup, and then reimport the exported data into SR to restore the data.
We can export the data of the serialized complex type to the file as binary, and then restore the binary to the complex type through deserialization. (e.g. DataTypeAggState::serialize/deserialize)
support stream load import
Use case
create table a_table(
k1 int null,
k2 agg_state<max_by(int not null,int)> generic,
k3 agg_state<group_concat(string)> generic
)
aggregate key (k1)
distributed BY hash(k1) buckets 3
properties("replication_num" = "1");
insert into a_table values(1,max_by_state(3,1),group_concat_state('a'));
insert into a_table values(1,max_by_state(2,2),group_concat_state('bb'));
insert into a_table values(2,max_by_state(1,3),group_concat_state('ccc'));
select * from a_table INTO OUTFILE "file:///mnt/disk3/root/sr/tmp.csv";
LOAD DATA LOCAL INFILE 'tmp.csv*' INTO TABLE a_table COLUMNS TERMINATED BY ',' LINES TERMINATED BY '\n';