这应该在mysql中测试，而不是postgresql:

SELECT table_schema, # "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) # "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema; 

我使用这个shell脚本来跟踪表大小(以字节和行数为单位)

#!/bin/sh

export MYSQL_PWD=XXXXXXXX
TABLES="table1 table2 table3"

for TABLE in $TABLES;
do
        FILEPATH=/var/lib/mysql/DBNAME/$TABLE.ibd
        TABLESIZE=`wc -c $FILEPATH | awk '{print $1}'`
        #Size in Bytes
        mysql -D scarprd_self -e "INSERT INTO tables_sizes (table_name,table_size,measurement_type) VALUES ('$TABLE', '$TABLESIZE', 'BYTES');"
        #Size in rows
        ROWSCOUNT=$(mysql -D scarprd_self -e "SELECT COUNT(*) AS ROWSCOUNT FROM $TABLE;")
        ROWSCOUNT=${ROWSCOUNT//ROWSCOUNT/}
        mysql -D scarprd_self -e "INSERT INTO tables_sizes (table_name,table_size,measurement_type) VALUES ('$TABLE', '$ROWSCOUNT', 'ROWSCOUNT');"
        mysql -D scarprd_self -e "DELETE FROM tables_sizes WHERE measurement_datetime < TIMESTAMP(DATE_SUB(NOW(), INTERVAL 365 DAY));"
done

它假设有这个MySQL表

CREATE TABLE `tables_sizes` (
  `table_name` VARCHAR(128) NOT NULL,
  `table_size` VARCHAR(25) NOT NULL,
  `measurement_type` VARCHAR(10) NOT NULL CHECK (measurement_type IN ('BYTES','ROWSCOUNT')),
  `measurement_datetime` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP()
) ENGINE=INNODB DEFAULT CHARSET=utf8

如果你有ssh访问权限，你可能想简单地尝试du -hc /var/lib/mysql(或不同的datadir，在my.cnf中设置)。

下面是另一种使用bash命令行的方法。

for i in `mysql -NB -e 'show databases'`; do echo $i; mysql -e "SELECT table_name AS 'Tables', round(((data_length+index_length)/1024/1024),2) 'Size in MB' FROM information_schema.TABLES WHERE table_schema =\"$i\" ORDER BY (data_length + index_length) DESC" ; done

Size of all tables: Suppose your database or TABLE_SCHEMA name is "news_alert". Then this query will show the size of all tables in the database. SELECT TABLE_NAME AS `Table`, ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024),2) AS `Size (MB)` FROM information_schema.TABLES WHERE TABLE_SCHEMA = "news_alert" ORDER BY (DATA_LENGTH + INDEX_LENGTH) DESC; Output: +---------+-----------+ | Table | Size (MB) | +---------+-----------+ | news | 0.08 | | keyword | 0.02 | +---------+-----------+ 2 rows in set (0.00 sec) For the specific table: Suppose your TABLE_NAME is "news". Then SQL query will be- SELECT TABLE_NAME AS `Table`, ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024),2) AS `Size (MB)` FROM information_schema.TABLES WHERE TABLE_SCHEMA = "news_alert" AND TABLE_NAME = "news" ORDER BY (DATA_LENGTH + INDEX_LENGTH) DESC; Output: +-------+-----------+ | Table | Size (MB) | +-------+-----------+ | news | 0.08 | +-------+-----------+ 1 row in set (0.00 sec)

SELECT TABLE_NAME AS table_name, 
table_rows AS QuantofRows, 
ROUND((data_length + index_length) /1024, 2 ) AS total_size_kb 
FROM information_schema.TABLES
WHERE information_schema.TABLES.table_schema = 'db'
ORDER BY (data_length + index_length) DESC; 

以上2个都是在mysql上测试的