Clickhouse-常用系统表查询

--查询表容量SQL语句

SELECT
database,
table AS table_name,
sum(rows) AS row_num,
formatReadableSize(sum(data_uncompressed_bytes)) AS org_size,
formatReadableSize(sum(data_compressed_bytes)) AS compress_size,
round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100, 0) AS compress_ratio
FROM system.parts
WHERE database='default'
GROUP BY table order by sum(rows) desc;

上图个字段含义：

database：数据库名称
table_name：表名称
row_num：数据行数
org_size：表原始尺寸
compress_size：压缩后的尺寸（真实占用磁盘空间大小）
compress_ratio：压缩率