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.