刚刚在其他地方回答了这个问题，但我今天遇到了同样的问题，这就是我所做的，它现在正在工作：
#app/models/data_warehouse.rb
class DataWarehouse < ActiveRecord::Base
establish_connection "redshift_staging"
#or, if you want to have a db per environment
#establish_connection "redshift_#{Rails.env}"
end
请注意，我们连接的是 5439，而不是默认的 5432，所以我指定了端口
另外，我指定了一个模式 beta，这是我们用于不稳定聚合的模式，您可以如上所述为每个环境使用不同的数据库，或者使用各种模式并将它们包含在 ActiveRecord 的搜索路径中
#config/database.yml
redshift_staging:
adapter: postgresql
encoding: utf8
database: db03
port: 5439
pool: 5
schema_search_path: 'beta'
username: admin
password: supersecretpassword
host: db03.myremotehost.us #your remote host here, might be an aws url from Redshift admin console
###OPTION 2，直接PG连接
class DataWarehouse < ActiveRecord::Base
attr_accessor :conn
def initialize
@conn = PG.connect(
database: 'db03',
port: 5439,
pool: 5,
schema_search_path: 'beta',
username: 'admin',
password: 'supersecretpassword',
host: 'db03.myremotehost.us'
)
end
end
[DEV] main:0> redshift = DataWarehouse
E, [2014-07-17T11:09:17.758957 #44535] ERROR -- : PG::InsufficientPrivilege: ERROR: permission denied to set parameter "client_min_messages" to "notice" : SET client_min_messages TO 'notice'
(pry) output error: #<ActiveRecord::StatementInvalid: PG::InsufficientPrivilege: ERROR: permission denied to set parameter "client_min_messages" to "notice" : SET client_min_messages TO 'notice'>
更新：
我最终选择了选项 1，但现在出于多种原因使用此适配器：
https://github.com/fiksu/activerecord-redshift-adapter
原因 1：ActiveRecord postgresql 适配器设置 client_min_messages
原因 2：适配器还尝试设置时区，这是 redshift 不允许的 (http://docs.aws.amazon.com/redshift/latest/dg/c_redshift-and-postgres-sql.html)
原因 3：即使您为前两个错误更改 ActiveRecord 中的代码，您也会遇到其他错误，抱怨 Redshift 正在使用 Postgresql 8.0，此时我转向适配器，如果我发现更好的东西，我会重新访问和更新稍后。
我将我的表重命名为 base_aggregate_redshift_tests（注意复数），以便 ActiveRecord 可以轻松连接，如果您无法在 redshift 中更改表名，请使用我在下面注释掉的 set_table 方法
#Gemfile:
gem 'activerecord4-redshift-adapter', github: 'aamine/activerecord4-redshift-adapter'
选项 1
#config/database.yml
redshift_staging:
adapter: redshift
encoding: utf8
database: db03
port: 5439
pool: 5
username: admin
password: supersecretpassword
host: db03.myremotehost.us
timeout: 5000
#app/models/base_aggregates_redshift_test.rb
#Model named to match my tables in Redshift, if you want you can set_table like I have commented out below
class BaseAggregatesRedshiftTest < ActiveRecord::Base
establish_connection "redshift_staging"
self.table_name = "beta.base_aggregates_v2"
end
在控制台中使用 self.table_name -- 注意它会查询正确的表，因此您可以随意命名模型
[DEV] main:0> redshift = BaseAggregatesRedshiftTest.first
D, [2014-07-17T15:31:58.678103 #43776] DEBUG -- : BaseAggregatesRedshiftTest Load (45.6ms) SELECT "beta"."base_aggregates_v2".* FROM "beta"."base_aggregates_v2" LIMIT 1
选项 2
#app/models/base_aggregates_redshift_test.rb
class BaseAggregatesRedshiftTest < ActiveRecord::Base
set_table "beta.base_aggregates_v2"
ActiveRecord::Base.establish_connection(
adapter: 'redshift',
encoding: 'utf8',
database: 'staging',
port: '5439',
pool: '5',
username: 'admin',
password: 'supersecretpassword',
search_schema: 'beta',
host: 'db03.myremotehost.us',
timeout: '5000'
)
end
#in console, abbreviated example of first record, now it's using the new name for my redshift table, just assuming I've got the record at base_aggregates_redshift_tests because I didn't set the table_name
[DEV] main:0> redshift = BaseAggregatesRedshiftTest.first
D, [2014-07-17T15:09:39.388918 #11537] DEBUG -- : BaseAggregatesRedshiftTest Load (45.3ms) SELECT "base_aggregates_redshift_tests".* FROM "base_aggregates_redshift_tests" LIMIT 1
#<BaseAggregatesRedshiftTest:0x007fd8c4a12580> {
:truncated_month => Thu, 31 Jan 2013 19:00:00 EST -05:00,
:dma => "Cityville",
:group_id => 9712338,
:dma_id => 9999
}
祝你好运！