NullableVsInt

NullableVsInt.sql

Denny Crane [not a Yandex bot], [Mar 10, 2020 at 6:34:43 PM (2020-03-10, 6:34:50 PM)]:
create table XXN (A Int64, B Nullable(Int64)) Engine=MergeTree order by tuple()
insert into XXN select 45545645, null from numbers(100000000);


select column, formatReadableSize(sum(column_bytes_on_disk)) bytes_on_disk, formatReadableSize(sum(column_data_uncompressed_bytes)) uncompressed
from system.parts_columns 
where active = 1 and table like '%XXN%' 
group by database,table, column

┌─column─┬─bytes_on_disk─┬─uncompressed─┐
│ A      │ 3.76 MiB      │ 762.94 MiB   │
│ B      │ 4.38 MiB      │ 858.31 MiB   │
└────────┴───────────────┴──────────────┘

select count(), A  from XXN group by A

┌───count()─┬────────A─┐
│ 100000000 │ 45545645 │
└───────────┴──────────┘

1 rows in set. Elapsed: 0.039 sec. Processed 100.00 million rows, 800.00 MB (2.56 billion rows/s., 20.49 GB/s.)

select count(), B  from XXN group by B

┌───count()─┬────B─┐
│ 100000000 │ ᴺᵁᴸᴸ │
└───────────┴──────┘

1 rows in set. Elapsed: 0.096 sec. Processed 100.00 million rows, 900.00 MB (1.04 billion rows/s., 9.39 GB/s.)


3.5M Mar 10 21:43 A.bin
286K Mar 10 21:43 A.mrk2
3.4M Mar 10 21:43 B.bin
286K Mar 10 21:43 B.mrk2
434K Mar 10 21:43 B.null.bin
286K Mar 10 21:43 B.null.mrk2
 303 Mar 10 21:43 checksums.txt
  67 Mar 10 21:43 columns.txt
   8 Mar 10 21:43 count.txt