Configuration parameters

Vertica supports a wide variety of configuration parameters that affect many facets of database behavior. These parameters can be set with the appropriate ALTER statements at one or more levels, listed here in descending order of precedence:

  1. User (ALTER USER)

  2. Session (ALTER SESSION)

  3. Node (ALTER NODE)

  4. Database (ALTER DATABASE)

Not all parameters can be set at all levels. Consult the documentation of individual parameters for restrictions.

You can query the CONFIGURATION_PARAMETERS system table to obtain the current settings for all user-accessible parameters. For example, the following query returns settings for partitioning parameters: their current and default values, which levels they can be set at, and whether changes require a database restart to take effect:

=> SELECT parameter_name, current_value, default_value, allowed_levels, change_requires_restart
      FROM configuration_parameters  WHERE parameter_name ILIKE '%partitioncount%';
    parameter_name    | current_value | default_value | allowed_levels | change_requires_restart
----------------------+---------------+---------------+----------------+-------------------------
 MaxPartitionCount    | 1024          | 1024          | NODE, DATABASE | f
 ActivePartitionCount | 1             | 1             | NODE, DATABASE | f
(2 rows)

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