> ## Documentation Index > Fetch the complete documentation index at: https://docs.bytebase.com/llms.txt > Use this file to discover all available pages before exploring further. # Database > Identify the exact database target before querying data or proposing a database change. A Bytebase **Database** is a record of a database managed through a registered [Instance](/concepts/instance). It identifies the database to query or change, belongs to one [Project](/concepts/project), and displays its synchronized schema metadata. For PostgreSQL, it corresponds to a native database containing schemas and tables; other engines map differently, as shown below. For example, an HR application's `hr_test` and `hr_prod` are separate database targets, even when their tables have identical names. The database and its rows remain on the database server. Bytebase discovery records its name and schema information without creating a second copy of the data. ## Database versus Instance An **Instance** represents a registered server or service and stores how Bytebase accesses it. A **Database** identifies a database within that instance. Select the database when querying its data or proposing changes to its schema; open the instance to manage connection settings and database discovery. Database names can repeat across instances. Check the instance and displayed environment; an explicit database environment overrides the instance's environment. ## What Database means for each engine | Engine | What appears as a Bytebase Database | Example table location | | -------------- | ------------------------------------------------- | ----------------------------------------------------- | | **PostgreSQL** | A native database, containing one or more schemas | Database `hr_test`, schema `public`, table `employee` | | **MySQL** | A native database; MySQL also calls it a schema | Database `hr_test`, table `employee` | | **SQL Server** | A native database, containing schemas | Database `hr_test`, schema `dbo`, table `employee` | | **Oracle** | A user-owned schema | Schema `HR_TEST`, table `EMPLOYEE` | PostgreSQL and SQL Server schemas, such as `public` and `dbo`, are namespaces within a database. MySQL treats database and schema as synonyms. For Oracle, Bytebase lists user-owned schemas as databases. Selecting `HR_TEST` sets the current schema on the instance's service/SID connection; it does not select a PDB. Preserve the discovered name's case. See [Instance](/concepts/instance) for what the instance represents in each engine. ## How a database appears in Bytebase **Discovery:** after an instance is connected, Bytebase reads the databases visible to the instance's database account. It creates a record for each database allowed by the instance's discovery filter and periodically synchronizes the schema metadata. Project-instance databases join the owning project. Databases discovered on workspace instances initially belong to the built-in project displayed as **Unassigned** until an authorized operator assigns them to a team's project. Reassigning a database changes its management in Bytebase without moving its data. See [instance scope](/concepts/instance#workspace-and-project-instances) for transfer restrictions. **Creation:** for supported engines, an operator with instance access and Plan/Issue creation permissions can submit **Create Database**. Execution creates the physical database. Databases provisioned externally can be discovered afterward. ## Inspect a database 1. Open your project's **Databases** page and select a database. 2. Check its **Instance** and **Environment** in the header to confirm the target. 3. Inspect the database's tables and schemas. Open a table to see its columns and structure. 4. If you have query access, click **SQL Editor** to open that database as your target. A sample database header identifies its environment and instance above the schema and table list In this example, `hr_test` is in Test on **Sample Project Instance**. The table list is filtered to `public.employee`. The schema view reflects the latest synchronized metadata. If a recent table change is missing, use **Sync Database** or ask the instance operator to check synchronization. Opening SQL Editor also requires query permission, such as the **SQL Editor Read User** [role](/security/database-permission/request). Continue with the [UI Quick Start](/get-started/step-by-step/change-schema), [Plan](/concepts/plan), or [SQL Review](/concepts/sql-review).