clickhouse数据维护

# clickhouse 数据维护

# 查看数据库、表存储情况

# 查看库数据情况(库：dispatcher)

SELECT
    sum(rows) AS `总行数`,
    formatReadableSize(sum(data_uncompressed_bytes)) AS `原始大小`,
    formatReadableSize(sum(data_compressed_bytes)) AS `压缩大小`,
    round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100, 0) AS `压缩率`,
    `table` AS `表名`
    FROM system.parts where database = 'dispatcher' group by `table`;

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# 查看单表数据情况(库：dispatcher,表：gnss)

SELECT
    column AS `字段名`,
    any(type) AS `类型`,
    formatReadableSize(sum(column_data_uncompressed_bytes)) AS `原始大小`,
    formatReadableSize(sum(column_data_compressed_bytes)) AS `压缩大小`,
    round(sum(column_data_uncompressed_bytes) / sum(column_data_compressed_bytes), 2) AS `压缩率`,
    sum(rows) AS `行数`
    FROM system.parts_columns
    WHERE (database = 'dispatcher') AND (table = 'gnss')
    GROUP BY column
    ORDER BY column ASC;

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# 查看表信息(库：dispatcher、表：gnss)

select
    database,
    table,
    formatReadableSize(size) as size,
    formatReadableSize(bytes_on_disk) as bytes_on_disk,
    formatReadableSize(data_uncompressed_bytes) as data_uncompressed_bytes,
    formatReadableSize(data_compressed_bytes) as data_compressed_bytes,
    compress_rate,
    rows,
    days,
    formatReadableSize(avgDaySize) as avgDaySize
from
(
    select
        database,
        table,
        sum(bytes) as size,
        sum(rows) as rows,
        min(min_date) as min_date,
        max(max_date) as max_date,
        sum(bytes_on_disk) as bytes_on_disk,
        sum(data_uncompressed_bytes) as data_uncompressed_bytes,
        sum(data_compressed_bytes) as data_compressed_bytes,
        (data_compressed_bytes / data_uncompressed_bytes) * 100 as compress_rate,
        max_date - min_date as days,
        size / (max_date - min_date) as avgDaySize
    from system.parts
    where active 
     and database = 'dispatcher'
     and table = 'gnss'
    group by
        database,
        table
);

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# clickhouse库分区

# 查看库有哪些分区(库：dispatcher、表：gnss、)

SELECT
    partition AS `分区`,
    sum(rows) AS `总行数`,
    formatReadableSize(sum(data_uncompressed_bytes)) AS `原始大小`,
    formatReadableSize(sum(data_compressed_bytes)) AS `压缩大小`,
    round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100, 0) AS `压缩率`
    FROM system.parts
    WHERE (database IN ('dispatcher')) AND (table IN ('gnss'))
    GROUP BY partition
    ORDER BY partition ASC;

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# 查看库有哪些分区(库：dispatcher、表：gnss、分区LIKE：2024%)

SELECT
    partition AS `分区`,
    sum(rows) AS `总行数`,
    formatReadableSize(sum(data_uncompressed_bytes)) AS `原始大小`,
    formatReadableSize(sum(data_compressed_bytes)) AS `压缩大小`,
    round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100, 0) AS `压缩率`
    FROM system.parts
    WHERE (database IN ('dispatcher')) AND (table IN ('gnss')) AND (partition LIKE '2024%')
    GROUP BY partition
    ORDER BY partition ASC;

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# 删除分区(库：dispatcher、表：gnss、分区：202407)

分区clickhouse设置ttl (opens new window)

alter table dispatcher.gnss drop partition '202407';

# 设置分区过期删除(注意：不要在生产高峰期执行)

按表字段时间来进行删除：timestamp

ALTER TABLE dispatcher.gnss MODIFY TTL timestamp + INTERVAL 5 month;

ALTER TABLE dispatcher.gnss MODIFY TTL 0;

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# 查看单表字段信息(库：dispatcher、表：gnss)

SELECT
    column AS `字段名`,
    any(type) AS `类型`,
    formatReadableSize(sum(column_data_uncompressed_bytes)) AS `原始大小`,
    formatReadableSize(sum(column_data_compressed_bytes)) AS `压缩大小`,
    round(sum(column_data_uncompressed_bytes) / sum(column_data_compressed_bytes), 2) AS `压缩率`,
    sum(rows) AS `行数`
FROM system.parts_columns
WHERE (database = 'dispatcher') AND (table = 'gnss')
GROUP BY column
ORDER BY column ASC;

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上次更新: 2025/01/23, 10:34:52

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