CLICKHOUSE

Материал из megapuper
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SHOW DATABASES - выводит список всех баз данных
SHOW TABLES - выводит список таблиц выбранной базы
SHOW PROCESSLIST - выводит список запросов выполняющихся в выбранной базе
SHOW GRANTS - выводит список привилегий пользователя
DESCRIBE TABLE stat - вывести описание столбцов таблицы


Бекап в Native формате

clickhouse-client --query="SELECT * FROM table FORMAT Native" > table.native
Native is the most efficient format 
CSV, TabSeparated, JSONEachRow are more portable: you may import/export data to another DBMS.

Dump of metadata:
clickhouse-client --query="SHOW CREATE TABLE table" --format=TabSeparatedRaw > table.sql

Restore of metadata:
clickhouse-client < table.sql

Restore of data:
clickhouse-client --query="INSERT INTO table FORMAT Native" < table.native

https://stackoverflow.com/questions/57005443/clickhouse-how-to-take-incremental-backup-of-clickhouse-db-for-both-partitoned


KILL QUERY WHERE query_id='2-857d-4a57-9ee0-327da5d60a90' - принудительно останавливает все запросы с указанным query_id


select parts.*,
       columns.compressed_size,
       columns.uncompressed_size,
       columns.ratio
from (
         select table,
                formatReadableSize(sum(data_uncompressed_bytes))          AS uncompressed_size,
                formatReadableSize(sum(data_compressed_bytes))            AS compressed_size,
                sum(data_compressed_bytes) / sum(data_uncompressed_bytes) AS ratio
         from system.columns
         where database = currentDatabase()
         group by table
         ) columns
         right join (
   select table,
           sum(rows)                                            as rows,
           max(modification_time)                               as latest_modification,
           formatReadableSize(sum(bytes))                       as disk_size,
           formatReadableSize(sum(primary_key_bytes_in_memory)) as primary_keys_size,
           any(engine)                                          as engine,
           sum(bytes)                                           as bytes_size
    from system.parts
    where active and database = currentDatabase()
    group by database, table
    ) parts on columns.table = parts.table
order by parts.bytes_size desc;

https://clickhouse.com/docs/ru/sql-reference/
https://github.com/AlexAkulov/clickhouse-backup/releases/tag/v1.0.0 https://gist.github.com/sanchezzzhak/511fd140e8809857f8f1d84ddb937015