doris/clickhouse常用sql

一、doris常用SQL

1、doris统计数据库的总大小（单位：MB）

SELECT 
    table_schema AS database_name,
    ROUND(SUM(data_length) / 1024 / 1024, 2) AS database_size_MB
FROM information_schema.tables
WHERE table_schema NOT IN ('information_schema', 'sys', 'mysql')
GROUP BY table_schema;

2、doris查询所有数据库大小排名（从大到小）

SELECT 
    table_schema AS database_name,
    ROUND(SUM(data_length) / 1024 / 1024, 2) AS database_size_MB
FROM information_schema.tables
GROUP BY table_schema
ORDER BY database_size_MB DESC;

3、 综合查询某数据库下各表的：表名、行数、大小（MB）

SELECT 
    table_name,
    table_rows AS row_count,
    ROUND(data_length / 1024 / 1024, 2) AS table_size_MB
FROM information_schema.tables
WHERE table_schema = 'your_database'
ORDER BY table_size_MB DESC;

4、整个数据库的总行数 & 总大小：

SELECT 
    table_schema AS database_name,
    SUM(table_rows) AS total_rows,
    ROUND(SUM(data_length) / 1024 / 1024, 2) AS total_size_MB
FROM information_schema.tables
WHERE table_schema = 'your_database'
GROUP BY table_schema;

5、查询数据库中是否存在 AGGREGATE 类型的表

SELECT 
    table_schema,
    table_name,
    engine
FROM information_schema.tables
WHERE engine = 'OLAP'
  AND create_statement LIKE '%AGGREGATE KEY%'
  AND table_schema = 'your_database';

二、clickhouse常用SQL

1、统计所有表的原始数据大小（未压缩）

SELECT
    database,
    name AS table_name,
    formatReadableSize(sum(bytes_on_disk)) AS raw_size
FROM system.tables
WHERE database = 'your_database_name'  -- 指定数据库名（可选）
GROUP BY database, table_name
ORDER BY sum(bytes_on_disk) DESC;

2、统计所有表的压缩后磁盘大小

SELECT
    database,
    name AS table_name,
    formatReadableSize(sum(data_compressed_bytes)) AS compressed_size,
    formatReadableSize(sum(data_uncompressed_bytes)) AS uncompressed_size,
    round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100, 2) AS compression_ratio
FROM system.parts
WHERE active  -- 仅统计活跃的分区
  AND database = 'your_database_name'  -- 指定数据库名（可选）
GROUP BY database, table_name
ORDER BY sum(data_compressed_bytes) DESC;

3、统计所有表的行数及压缩后大小

SELECT
    database,
    name AS table_name,
    formatReadableSize(sum(bytes_on_disk)) AS disk_size,
    sum(rows) AS total_rows,
    formatReadableSize(sum(data_compressed_bytes)) AS compressed_size,
    formatReadableSize(sum(data_uncompressed_bytes)) AS uncompressed_size,
    round((compressed_size / uncompressed_size) * 100, 2) AS compression_ratio
FROM system.parts
WHERE active  -- 仅统计活跃分区（排除临时或已删除的分区）
  AND database = 'your_database_name'  -- 指定数据库名（可选）
GROUP BY database, table_name
ORDER BY compressed_size DESC;