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Module: ActiveRecord::ConnectionAdapters::DatabaseLimits

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In:
AbstractAdapter, AbstractMysqlAdapter, Mysql2Adapter, PostgreSQLAdapter, SQLite3Adapter
Defined in: activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb

Instance Method Summary

Instance Method Details

#allowed_index_name_length

Returns the maximum allowed length for an index name. This limit is enforced by Rails and is less than or equal to #index_name_length. The gap between #index_name_length is to allow internal Rails operations to use prefixes in temporary operations.

[ GitHub ] 

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 26



def allowed_index_name_length
  index_name_length
end


  








  

    #column_name_length  
  



  

    

Returns the maximum length of a column name.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 12



def column_name_length
  64
end


  








  

    #columns_per_multicolumn_index  
  



  

    

Returns the maximum number of columns in a multicolumn index.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 46



def columns_per_multicolumn_index
  16
end


  








  

    #columns_per_table  
  



  

    

Returns the maximum number of columns per table.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 36



def columns_per_table
  1024
end


  








  

    #in_clause_length  
  



  

    

Returns the maximum number of elements in an IN (x,y,z) clause. nil means no limit.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 52



def in_clause_length
  nil
end


  








  

    #index_name_length  
  



  

    

Returns the maximum length of an index name.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 31



def index_name_length
  64
end


  








  

    #indexes_per_table  
  



  

    

Returns the maximum number of indexes per table.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 41



def indexes_per_table
  16
end


  








  

    #joins_per_query  
  



  

    

Returns maximum number of joins in a single query.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 62



def joins_per_query
  256
end


  








  

    #sql_query_length  
  



  

    

Returns the maximum length of an SQL query.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 57



def sql_query_length
  1048575
end


  








  

    #table_alias_length  
  



  

    

Returns the maximum length of a table alias.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 7



def table_alias_length
  255
end


  








  

    #table_name_length  
  



  

    

Returns the maximum length of a table name.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb', line 17



def table_name_length
  64
end