Hologres:Overview

Hologres is deeply integrated with the Alibaba Cloud account system. Hologres accounts include Alibaba Cloud accounts and RAM users. The following table describes the Hologres accounts. To grant permissions on a Hologres instance to Alibaba Cloud accounts and RAM users, you must use their logon accounts or account IDs. For more information, see Logon accounts and Account IDs.

Account type	Description
Alibaba Cloud account	Alibaba Cloud accounts are used to create and manage Hologres instances. For example, you can use your Alibaba Cloud account to log on to the Hologres console, create a database, change the billing method of an instance from pay-as-you-go to subscription, and grant permissions on objects to other users.
RAM user	After you create a RAM user by using your Alibaba Cloud account and grant permissions to the RAM user, the RAM user can create and manage Hologres instances within the scope of the granted permissions. For example, the RAM user can log on to the Hologres console, create a database, change the billing method of an instance from pay-as-you-go to subscription, and grant permissions on objects to other users. RAM users are subordinate to Alibaba Cloud accounts and do not actually own resources. All resources belong only to Alibaba Cloud accounts.
Custom account	You can use a custom account to perform operations on databases within the scope of the granted permissions. For example, you can use a custom account to create or delete databases, tables, and views, and connect to databases.

When you grant permissions to an Alibaba Cloud account or a RAM user, you must use the logon account of the Alibaba Cloud account. You can obtain the logon account on the Security Settings page of the Account Center.

• When you grant permissions to an Alibaba Cloud account, the full expression of the Alibaba Cloud account must contain the logon account. The following table describes the account formats.

  Account format	Description	Example
  ALIYUN$<Login Account>@aliyun.com	<Login Account>: the logon account of the Alibaba Cloud account.	ALIYUN$company@aliyun.com
  <Login Account>@aliyun.com		company@aliyun.com

• When you grant permissions to a RAM user, the full expression of the RAM user must contain the logon account of the Alibaba Cloud account to which the RAM user belongs. The following table describes the account formats.

  Account format	Description	Example
  <subUserName>@<Login Account>.onaliyun.com	The account formats contain the following parameters: <subUserName>: the name of the RAM user. <Login Account>: the logon account of the Alibaba Cloud account. <AccountID>: the account ID of the Alibaba Cloud account.	holouser@company.onaliyun.com
  <subUserName>@<Login Account>		holouser@company
  <subUserName>@<Account ID>.onaliyun.com		holouser@123456789xxxx
  RAM$<subUserName>		RAM$holo_test
  RAM$<Login Account>:<subUserName>		RAM$company:holouser
  RAM$<Account ID>:<subUserName>		RAM$123456789xxxx:holouser
  <subUserName>@<Account ID>		holouser@123456789xxxx

An account ID is a string of digits. Example: 189813715xxxx. You can obtain the account ID on the Security Settings page of the Account Center.

The account ID of a RAM user is the UID of the RAM user. You can obtain the UID on the user details page in the Resource Access Management (RAM) console. When you grant permissions to a RAM user by using its UID in Hologres, the UID must be in the p4_UID format. Example: p4_12333388xxx.

The following sample statements show how to grant permissions to users in Hologres by using account IDs:

create USER "189813715xxxx"; // Authorize the user whose Alibaba Cloud account ID is 189813715xxxx to connect to Hologres. 
create USER "p4_12333388xxx" superuser;// Assign the superuser role to the RAM user whose UID is 12333388xxx. 

You can execute the following statement in Hologres to view your account ID:

SELECT current_user;

You can use a custom account to perform operations on databases within the scope of the granted permissions. For example, you can use a custom account to create or delete databases, tables, and views, and connect to databases. Custom accounts can be used only in Hologres instances. For more information about how to create a custom account, see Create a custom account.