Question

我有一个在MySql DB上运行的Rails 2.3.8应用程序。是否可以通过Rails应用程序检查数据库的实际大小（以兆字节为单位）？如果是这样，我可以获得详细的视图，例如某个表占用多少兆字节？

有什么想法吗？

Answer 1

我在前一段时间创建了gem

gem 'mysql_rake_tasks', '~> 0.1.0'
bundle install

rake db:mysql:stats
+--------------------------------+---------------+-----------+----------+------------+
| Table Name                     |          Rows | Data Size | IDX Size | Total Size |
+--------------------------------+---------------+-----------+----------+------------+
| fish                           |  1.41 Million |   93.6 MB |  41.1 MB |     135 MB |
| birds                          |             0 |     16 KB |  0 Bytes |      16 KB |
| cats                           |            14 |     16 KB |  0 Bytes |      16 KB |
| schema_migrations              |             7 |     16 KB |  0 Bytes |      16 KB |
| users                          |             5 |     16 KB |    32 KB |      48 KB |
+--------------------------------+---------------+-----------+----------+------------+
|                                                                       |     135 MB |
+--------------------------------+---------------+-----------+----------+------------+
Database: mydb_development  MySQL Server Version: 5.1.58

Answer 2

您可以从INFORMATION_SCHEMA

获取所需内容

该页面的一些查询：

SELECT table_schema 'database',
concat( round( sum( data_length + index_length ) / ( 1024 *1024 ) , 2 ) , 'M' ) size
FROM information_schema.TABLES
WHERE ENGINE=('MyISAM' || 'InnoDB' )
GROUP BY table_schema;

Answer 3

如果你只想把结果重新变成Hash，那么这个效果非常好：

db_name = Rails.configuration.database_configuration[Rails.env]["database"]

sql = "SELECT table_name AS name, table_rows, data_length, index_length FROM information_schema.TABLES  WHERE table_schema = '#{db_name}' ORDER BY (data_length + index_length) DESC;"

table_data = ActiveRecord::Base.connection.execute(sql).map{|r| {name: r[0], rows: r[1], data_size: r[2], index_size: r[3]}}

然后，如果您在Rails控制台中并想要转储结果：

c,d,i=0,0,0;table_data.each {|r| print r[:name].ljust(30),helper.number_with_delimiter(r[:rows]).rjust(16)," rows", helper.number_to_human_size(r[:data_size]).rjust(12), helper.number_to_human_size(r[:index_size]).rjust(12), helper.number_to_human_size(r[:data_size] + r[:index_size]).rjust(12),"\n";c+=r[:rows];d+=r[:data_size];i+=r[:index_size]};print "-"*90,"\n","Total".ljust(30),helper.number_with_delimiter(c).rjust(16)," rows", helper.number_to_human_size(d).rjust(12), helper.number_to_human_size(i).rjust(12), helper.number_to_human_size(d+i).rjust(12),"\n"

通过Rails检查MySql数据库大小

3 个答案: