2.9 KiB
clickhouse-local
The clickhouse-local
program enables you to perform fast processing on local files, without having to deploy and configure the ClickHouse server.
Accepts data that represent tables and queries them using ClickHouse SQL dialect.
clickhouse-local
uses the same core as ClickHouse server, so it supports most of the features and the same set of formats and table engines.
By default clickhouse-local
does not have access to data on the same host, but it supports loading server configuration using --config-file
argument.
!!! warning
It is not recommended to load production server configuration into clickhouse-local
because data can be damaged in case of human error.
Usage
Basic usage:
clickhouse-local --structure "table_structure" --input-format "format_of_incoming_data" -q "query"
Arguments:
-S
,--structure
— table structure for input data.-if
,--input-format
— input format,TSV
by default.-f
,--file
— path to data,stdin
by default.-q
--query
— queries to execute with;
as delimeter.-N
,--table
— table name where to put output data,table
by default.-of
,--format
,--output-format
— output format,TSV
by default.--stacktrace
— whether to dump debug output in case of exception.--verbose
— more details on query execution.-s
— disablesstderr
logging.--config-file
— path to configuration file in same format as for ClickHouse server, by default the configuration empty.--help
— arguments references forclickhouse-local
.
Also there are arguments for each ClickHouse configuration variable which are more commonly used instead of --config-file
.
Examples
echo -e "1,2\n3,4" | clickhouse-local -S "a Int64, b Int64" -if "CSV" -q "SELECT * FROM table"
Read 2 rows, 32.00 B in 0.000 sec., 5182 rows/sec., 80.97 KiB/sec.
1 2
3 4
Previous example is the same as:
$ echo -e "1,2\n3,4" | clickhouse-local -q "CREATE TABLE table (a Int64, b Int64) ENGINE = File(CSV, stdin); SELECT a, b FROM table; DROP TABLE table"
Read 2 rows, 32.00 B in 0.000 sec., 4987 rows/sec., 77.93 KiB/sec.
1 2
3 4
Now let's output memory user for each Unix user:
$ ps aux | tail -n +2 | awk '{ printf("%s\t%s\n", $1, $4) }' | clickhouse-local -S "user String, mem Float64" -q "SELECT user, round(sum(mem), 2) as memTotal FROM table GROUP BY user ORDER BY memTotal DESC FORMAT Pretty"
Read 186 rows, 4.15 KiB in 0.035 sec., 5302 rows/sec., 118.34 KiB/sec.
┏━━━━━━━━━━┳━━━━━━━━━━┓
┃ user ┃ memTotal ┃
┡━━━━━━━━━━╇━━━━━━━━━━┩
│ bayonet │ 113.5 │
├──────────┼──────────┤
│ root │ 8.8 │
├──────────┼──────────┤
...