DC
insert into D values(1,1), (1,1);
optimize table D deduplicate;
SELECT *
FROM D
┌─A─┬─B─┐
│ 1 │ 1 │
│ 1 │ 1 │
└───┴───┘
optimize table D final deduplicate;
SELECT *
FROM D
┌─A─┬─B─┐
│ 1 │ 1 │
└───┴───┘
Size: a a a
DC
insert into D values(1,1), (1,1);
optimize table D deduplicate;
SELECT *
FROM D
┌─A─┬─B─┐
│ 1 │ 1 │
│ 1 │ 1 │
└───┴───┘
optimize table D final deduplicate;
SELECT *
FROM D
┌─A─┬─B─┐
│ 1 │ 1 │
└───┴───┘
DC
create table D (A Int64, B Int64) Engine=MergeTree() order by tuple();
insert into D values(1,1);
insert into D values(1,1);
optimize table D deduplicate; <--------------
SELECT *
FROM D
┌─A─┬─B─┐
│ 1 │ 1 │
└───┴───┘
DC
DC
deduplicate
-- имеет смысл только для MergeTree
. У остальных движков схлапывание по первичному ключу.DC
let i=1;for f in `ls -1` ; do echo $i $f;((i++)); echo "alter table XXXX attach part '$f';"|clickhouse-client ; done
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v19.17.5.18-stable
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<Error> bool DB::{anonymous}::checkPermissionsImpl(): Code: 412, e.displayText() = DB::Exception: Can't receive Netlink response: error -2, Stack trace:
DC
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