Methods
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Instance Public methods
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.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 24
def allowed_index_name_length
  index_name_length
end
column_name_length()

Returns the maximum length of a column name.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 10
def column_name_length
  64
end
columns_per_multicolumn_index()

Returns the maximum number of columns in a multicolumn index.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 44
def columns_per_multicolumn_index
  16
end
columns_per_table()

Returns the maximum number of columns per table.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 34
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.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 50
def in_clause_length
  nil
end
index_name_length()

Returns the maximum length of an index name.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 29
def index_name_length
  64
end
indexes_per_table()

Returns the maximum number of indexes per table.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 39
def indexes_per_table
  16
end
joins_per_query()

Returns maximum number of joins in a single query.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 60
def joins_per_query
  256
end
sql_query_length()

Returns the maximum length of an SQL query.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 55
def sql_query_length
  1048575
end
table_alias_length()

Returns the maximum length of a table alias.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 5
def table_alias_length
  255
end
table_name_length()

Returns the maximum length of a table name.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 15
def table_name_length
  64
end