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Metadb provides several configuration parameters to control server behavior and performance. You can modify these parameters using the alter system command.
Some parameters require restarting the server before they take effect.

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Viewing configuration

To view current configuration settings: 
list config;

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Setting parameters

Use the alter system command to change a configuration parameter: 
alter system set parameter_name = 'value';

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Available parameters

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checkpoint_segment_size

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checkpoint_segment_size
string
default:"3000"
Sets the maximum number of change events that will be processed before a checkpoint occurs.
The server must be restarted for this parameter to take effect.
Example: 
alter system set checkpoint_segment_size = '5000';
Increasing this value can improve throughput for high-volume data sources by reducing the frequency of checkpoint operations.

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external_sql_folio

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external_sql_folio
string
default:""
Sets the Git reference in the folio-analytics repository to be used for running external SQL.
When set to an empty string (default), running external SQL is disabled. Example: 
alter system set external_sql_folio = 'refs/tags/v1.8.0';
This parameter allows you to specify which version of the folio-analytics queries should be executed automatically.
You can use various Git reference formats:
  • Tags: refs/tags/v1.8.0
  • Branches: refs/heads/main
  • Commit SHA: Full 40-character commit hash

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external_sql_reshare

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external_sql_reshare
string
default:""
Sets the Git reference in the folio-reshare repository to be used for running external SQL.
When set to an empty string (default), running external SQL is disabled. Example: 
alter system set external_sql_reshare = 'refs/tags/v2.1.0';
This parameter works the same way as external_sql_folio but for the reshare repository. See External SQL directives for more information on configuring external SQL execution.

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max_poll_interval

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max_poll_interval
string
default:"1800000"
Sets a timeout in milliseconds for the interval between polls of a Kafka data source, during which change events are processed.
The server must be restarted for this parameter to take effect.
Example: 
alter system set max_poll_interval = '3600000';
The default value is 1,800,000 milliseconds (30 minutes). Increase this value if you have long-running processing operations that need more time between Kafka polls.

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Parameter types

All configuration parameter values are specified as string constants, even for numeric values.

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Restart requirements

The following parameters require a server restart to take effect:
  • checkpoint_segment_size
  • max_poll_interval
After changing these parameters, you must:
1

Stop the server

metadb stop
2

Start the server

metadb start
Parameters that don’t require a restart take effect immediately.

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