module ActiveRecord::ConnectionAdapters::DatabaseLimits

Public Instance Methods

allowed_index_name_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 34
def allowed_index_name_length
  index_name_length
end

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.

column_name_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 18
def column_name_length
  max_identifier_length
end

Returns the maximum length of a column name.

columns_per_multicolumn_index() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 56
def columns_per_multicolumn_index
  16
end

Returns the maximum number of columns in a multicolumn index.

columns_per_table() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 44
def columns_per_table
  1024
end

Returns the maximum number of columns per table.

in_clause_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 63
def in_clause_length
  nil
end

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

index_name_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 39
def index_name_length
  max_identifier_length
end

Returns the maximum length of an index name.

indexes_per_table() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 50
def indexes_per_table
  16
end

Returns the maximum number of indexes per table.

joins_per_query() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 74
def joins_per_query
  256
end

Returns maximum number of joins in a single query.

sql_query_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 68
def sql_query_length
  1048575
end

Returns the maximum length of an SQL query.

table_alias_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 13
def table_alias_length
  max_identifier_length
end

Returns the maximum length of a table alias.

table_name_length() Show source

# File activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb, line 24
def table_name_length
  max_identifier_length
end

Returns the maximum length of a table name.