This topic describes the terms used in AnalyticDB for MySQL.
Terms used in AnalyticDB for MySQL V3.0
The geographic location where the servers of AnalyticDB for MySQL are located. You must specify a region when purchasing AnalyticDB for MySQL. Once specified, the region cannot be changed.Note You can access an AnalyticDB for MySQL V3.0 cluster through only Alibaba Cloud Virtual Private Cloud (VPC). When purchasing an AnalyticDB for MySQL V3.0 cluster, you must also purchase an ECS instance for accessing the cluster and ensure that the cluster and ECS instance are located in the same region.
A zone is a physical area with an independent power grid and network within a region. Zones are interconnected over the internal network. Clusters that reside within the same zone have lower network latency between each other.
Databases belong to clusters. You can create multiple databases in a cluster. Databases in different clusters are physically isolated.
A cluster consists of multiple nodes. You must specify the node specifications when you purchase a cluster. The node specifications include the CPU, memory, and storage capacity.AnalyticDB for MySQL V3.0 supports the following types of node groups:
- Compute-intensive node groups (C series): All the data of these node groups is stored
in standard SSDs.
Compute-intensive node groups are ideal for services that require high performance and high query concurrency.
- Storage-intensive node groups (S series): These node groups use an architecture that
separates computing resources from storage resources. All the data of these node groups
is stored in HDDs.
Storage-intensive node groups are ideal for scenarios where there are lower requirements for query concurrency and performance. That is, the query response time is greater than 10 seconds.
- Compute-intensive node groups (C series): All the data of these node groups is stored in standard SSDs.
Databases are the basic unit in AnalyticDB for MySQL V3.0. You can purchase one or more databases of different specifications. A database is logically composed of partitions and physically composed of nodes.
Accounts are the subject for accessing databases in clusters within the specified permissions. Account names in the same cluster must be unique.AnalyticDB for MySQL supports the following types of accounts:
- Alibaba Cloud account: the account used to create and manage clusters. For example, you can use this account to log on to the AnalyticDB for MySQL console, change the billing method of clusters from pay-as-you-go to subscription, scale in or out clusters, and delete clusters.
- Resource Access Management (RAM) user: the account used to create and manage clusters within the specified permissions granted by the Alibaba Cloud account.
- Database account: the account used to manage databases within the specified permissions. For example, you can use this account to create or delete databases, connect to databases, and create or delete tables.
- Service account: the account used by an Alibaba Cloud technical support engineer to access your cluster. To obtain technical support from Alibaba Cloud, you must grant permissions to the service account to authorize an Alibaba Cloud technical support personnel. When the authorization period expires, the granted permissions are automatically revoked.
The account system and SQL syntax of AnalyticDB for MySQL V3.0 are compatible with those of MySQL. For more information, see CREATE USER.
A user-created database consists of multiple shards. The data of a table is distributed in shards based on the hash calculation result of the
distribution keyspecified during table creation. When you create a table, you only need to specify the
distribution key. The system automatically optimizes the number of shards for you. For more information, see CREATE TABLE.
AnalyticDB for MySQL V3.0 supports two types of tables: fact table and dimension table. Only fact tables support partitions. In AnalyticDB for MySQL V3.0, partitions are created in each shard. AnalyticDB for MySQL V3.0 supports only partitions.