den-crane

CREATE TABLE t
(
    key_zstd1    Int64 CODEC(ZSTD(1)),
    key_lz4      Int64 CODEC(LZ4),
    key_t64_zstd Int64 CODEC(T64,ZSTD(1)),
    key_int8     Int8 CODEC(ZSTD(1)),
    r Int32
)
ENGINE = MergeTree
ORDER BY (key_zstd1, r);

den-crane

create table x (a Int64, b Int64, c Int64, 
 u AggregateFunction(uniqHLL12, String), 
 t AggregateFunction(uniqTheta, String)) 
Engine=MergeTree order by (a,b,c);

insert into x select number%11111 a, number%44 b, number%3 c, uniqHLL12State(number::String), uniqThetaState(number::String)
from numbers(1e7) group by a,b,c;

optimize table x final;

den-crane

CREATE TABLE wide_rows2(`A` Int64, `D` Date, `S` String)
ENGINE = MergeTree PARTITION BY toYYYYMM(D) ORDER BY A
settings merge_with_ttl_timeout=300, materialize_ttl_recalculate_only = 1;

insert into wide_rows2 select number, toDate('2020-01-01')+ number%20, arrayMap(i-> cityHash64((number*i)%999), range(2000)) from numbers(1e5);
insert into wide_rows2 select number, toDate('2020-01-01')+ number%20, arrayMap(i-> cityHash64((number*i)%899), range(2000)) from numbers(1e5);
insert into wide_rows2 select number, toDate('2020-01-01')+ number%20, arrayMap(i-> cityHash64((number*i)%799), range(2000)) from numbers(1e5);
insert into wide_rows2 select number, toDate('2020-01-01')+ number%20, arrayMap(i-> cityHash64((number*i)%699), range(2000)) from numbers(1e5);
set materialize_ttl_after_modify=0;

den-crane

CH 1-node

SELECT
    count(),
    min(paramkey),
    max(paramkey),
    min(ind),
    max(ind)
FROM data_table
┌───count()─┬────────min(paramkey)─┬───────max(paramkey)─┬─min(ind)─┬──max(ind)─┐

den-crane

https://github.com/ClickHouse/ClickHouse/issues/47092#issuecomment-1485052499

23.3.8.21
<default>
   <access_management>1</access_management>
</default>

create user foo;
grant all on *.* to foo;

den-crane

create table test(tenant_id UInt32,  ts1 DateTime, timestamp DateTime)
engine=MergeTree
partition by toDate(ts1)
PRIMARY KEY (tenant_id, toStartOfHour(timestamp))
ORDER BY (tenant_id, toStartOfHour(timestamp),  timestamp)
as select 1, now() - number/10 x, x from numbers(1e8);

insert into test select number%1000, now() - number/10 x, 0 from numbers(1e8);

den-crane

Test data

clickhouse-client -q "select number A, now() B, 'x' C from numbers(1e6) format Parquet" > test.parquet

Maven

    <dependencies>

den-crane

create table A (pk_col Int64, col1 Float64, col4 Float64, day Date) Engine=Memory
as select * from values( 
            (1, 3, 4, today()), (1, 1, 4, today()), (1, 2, 0, today()-1), 
            (2, 3, 4, today()), (2, 3, 0, today()-1) );

Window function

den-crane

Buffer -> Replicated

create database test on cluster '{cluster}' Engine=Ordinary;

create table test.test on cluster '{cluster}' (A Int64) 
Engine = ReplicatedMergeTree('/clickhouse/{cluster}/tables/{database}/{table}', '{replica}') order by A;

create table test.test_b on cluster  '{cluster}' as test.test
Engine = Buffer(test, test, 1, 1, 2, 10, 100, 10000000, 100000000);

den-crane

create table idx( A Int64, D Date) Engine=MergeTree order by A partition by D;

insert into idx select number, today() from numbers(1e8);
insert into idx select number, today()-1 from numbers(1e8);

select sum(primary_key_bytes_in_memory), sum(primary_key_bytes_in_memory_allocated) 
from system.parts where table = 'idx' and active;
┌─sum(primary_key_bytes_in_memory)─┬─sum(primary_key_bytes_in_memory_allocated)─┐
│                           195360 │                                     264192 │
└──────────────────────────────────┴────────────────────────────────────────────┘