postgresql Rails 4 pgsql add_index 类型为 GIN 或 GiST
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Rails 4 pgsql add_index with type GIN or GiST
提问by Bill
In Rails it is possible to do:
在 Rails 中，可以执行以下操作：
add_index :table, :column_name, :using => 'btree'
add_index :table, :column_name, :using => 'btree'
Is it possible in Rails 4 with PGSQL to add a GINor GiSTindex like:
是否可以在带有 PGSQL 的 Rails 4 中添加一个GIN或GiST索引，如：
add_index :students, :name, :using => 'gin'
add_index :students, :name, :using => 'gin'
Or do I have use manual execute statements? The notion behind this is I would like to keep schema.rb instead of using structure.sql
或者我有使用手动执行语句吗？这背后的概念是我想保留 schema.rb 而不是使用 structure.sql
回答by Pronix
In Rails 4, you can now do something like this in a migration:
在 Rails 4 中，您现在可以在迁移中执行以下操作：
add_index :products, :data, using: :gin
回答by Josh
Wow! I had a few hairs turn gray on this one. I am using rails 4.2 and trying to run this migration and it was giving me the same error as people above.
哇！我有几根头发变白了。我正在使用 rails 4.2 并尝试运行此迁移，它给了我与上面的人相同的错误。
PG::UndefinedObject: ERROR: data type character varying has no default
I found out that you can in fact still continue to use schema.rb and do not have to use the config/application.rb
我发现您实际上仍然可以继续使用 schema.rb 而不必使用 config/application.rb
config.active_record.schema_format = :sql
The one major thing I was missing was installing postgres contrib modules. I made the assumption that features like gin and gist were already turned on. I never noticed but modules are shown in your schema.rb file. They appear at the top like this
我缺少的一件主要事情是安装 postgres contrib 模块。我假设 gin 和 gist 等功能已经打开。我从未注意到，但模块显示在您的 schema.rb 文件中。它们像这样出现在顶部
ActiveRecord::Schema.define(version: 20151203234708) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
enable_extension "pg_trgm"
enable_extension "fuzzystrmatch"
enable_extension "btree_gin"
enable_extension "btree_gist"
if you do not see btree_gin enabled, you can not use the code
如果你没有看到 btree_gin 启用，你不能使用代码
add_index :products, :data, using: :gin
you can install any module by running a migration like so. The changes will be reflected in your schema.rb
您可以通过像这样运行迁移来安装任何模块。更改将反映在您的 schema.rb 中
class InstallSomeContribPackages < ActiveRecord::Migration
def up
execute "CREATE EXTENSION IF NOT EXISTS btree_gin;"
execute "CREATE EXTENSION IF NOT EXISTS btree_gist;"
end
def down
execute "DROP EXTENSION IF EXISTS btree_gin;"
execute "DROP EXTENSION IF EXISTS btree_gist;"
end
end
here is a list of postgres modules
这是postgres 模块的列表
