Exploring Database Schemas

Schemas help you monitor performance, usage, and changes in your data models, enabling quicker issue identification and remediation.

Schema Tracking is available for PostgreSQL, SQL Server, and MySQL.
Schemas page displaying tracked database tables and schema-level metrics in Datadog

Configuration

To enable the schemas feature, add the collect_schemas parameter to your Database Monitoring configuration:

init_config:
instances:
  - dbm: true
    host: localhost
    port: 5432
    username: datadog
    password: 'ENC[datadog_user_database_password]'
    collect_schemas: true
    ## Optional: Connect to a different database if needed for `custom_queries`
    # dbname: '<DB_NAME>'

Tables overview

The Tables overview lists all tracked tables across your databases, grouped by table name, with the following columns:

ColumnDescription
# VariantsNumber of distinct versions of the table across all hosts.
# InstancesTotal number of table instances across all hosts. For example, if a table has two variants with seven and eight instances respectively, the total number of instances is 15.
# ColumnsCount of unique columns across all variants of the table on all hosts. For example, if one variant has columns A, B, C and another has A, B, D, the total unique columns would be four (A, B, C, D).
DatabasesNames of all databases containing this table across all hosts.
SchemasSchemas in which this table appears across all hosts.
Database HostsHosts where this table is present.

Each table row can be expanded to view its table variants and the following columns:

ColumnDescription
Variant IDUnique identifier for a variant (version) of this table.
# InstancesNumber of instances of this table for this variant.
# ColumnsNumber of unique columns in this table variant.
DatabasesAlphabetically sorted list of databases containing this table variant.
SchemasAlphabetically sorted list of schemas containing this table variant.
Database HostsAlphabetically sorted list of hosts where this table variant appears.

Viewing table variant details

To view more details about a table variant, click its row to open the table variant panel.

Table variant panel showing column definitions and an index for the inventory table

This panel shows you information about the variant (version), such as:

  • Definition: Includes columns, indexes, and foreign keys for this table variant.
  • Table Instances: All instances associated with this table variant.
  • Metrics: Table size, sequential scans, and other related metrics (last 7 days by default).
  • Queries: Queries involving this table variant (last 7 days by default).
  • Changes: Schema changes affecting this table variant (last 7 days by default).

Viewing table instance details

To view details for a specific table instance, go to the Table Instances tab in the table variant panel and click on a row.

Table instance panel displaying column and index details for the inventory table.

This opens a view similar to the table variant panel, showing the following information for the selected table instance:

  • Definition: Includes columns, indexes, and foreign keys for this table instance.
  • Metrics: Table size, sequential scans, and other related metrics (last 7 days by default).
  • Queries: Queries involving this table instance (last 7 days by default).
  • Changes: Schema changes affecting this table instance (last 7 days by default).

Recommendations

Recommendations highlight potential opportunities for schema optimization across your tables.

Each recommendation includes:

  • A detected issue, such as a missing primary key or an inefficient index.
  • An explanation of why the issue matters and how it impacts database performance or integrity.
  • A suggested fix, often an SQL statement that can be executed on the affected database.

Recommendations are available in aggregate (at the top of the page) and per table, with each applicable table showing its corresponding recommendations. For more information, see Recommendations.

Metrics overview

The Metrics overview displays dashboards for metrics associated with tracked tables across each DBMS.

Metrics overview showing total table instance count and key activity metrics across tracked database instances

Each dashboard includes the following metrics:

  • Total Table Instance Count
  • Fastest Changing Instances (%)
  • Fastest Changes Instances (bytes)
  • Most Accessed Instances
  • Largest Instances
  • Instances with Most Live Rows
  • Instances with the Largest Index Sizes
  • Instances with Access Exclusive Locks
  • Instances with Most Dead Rows
  • Instances with the Longest Last Vacuum Age
  • Instances with the Longest Last Auto Vacuum Age