Key Concepts ​

To understand how GreptimeDB manages and serves its data, you need to know about these building blocks of GreptimeDB.

Database ​

Similar to database in relational databases, time-series database is the minimal unit of data container, within which data can be managed and computed.

Time-Series Table ​

GreptimeDB designed time-series table to be the basic unit of data storage. It is similar to a table in a traditional relational database, but requires a timestamp column(We call it time index). The table holds a set of data that shares a common schema. It can be created using SQL CREATE TABLE, or inferred from the input data structure using the auto-schema feature. In a distributed deployment, a table can be split into multiple partitions that sit on different datanodes.

For more information about the data model of the time-series table, please refer to Data Model.

Table Region ​

Each partition of distributed table is called a region. A region may contain a sequence of continuous data, depending on the partition algorithm. Region information is managed by Metasrv. It's completely transparent to users who send write requests or queries.

Data Types ​

Data in GreptimeDB is strongly typed. Auto-schema feature provides some flexibility when creating a table. Once the table is created, data of the same column must share common data type.

Find all the supported data types in Data Types.