STV_WLM_SERVICE_CLASS_CONFIG
Records the service class configurations for WLM.
STV_WLM_SERVICE_CLASS_CONFIG is visible only to superusers. For more information, see Visibility of data in system tables and views.
Table columns
| Column name | Data type | Description |
|---|---|---|
| service_class | integer | ID for the service class. For a list of service class IDs, see WLM service class IDs. |
| queueing_strategy | character(32) | Reserved for system use. |
| num_query_tasks | integer | Current actual concurrency level of the service
class. If num_query_tasks and
target_num_query_tasks are different, a dynamic WLM
transition is in process.
A value of -1 indicates that Auto WLM is configured. |
| target_num_query_tasks | integer | Concurrency level set by the most recent WLM configuration change. |
| evictable | character(8) | Reserved for system use. |
| eviction_threshold | bigint | Reserved for system use. |
| query_working_mem | integer | Current actual amount of working memory, in MB per
slot, per node, assigned to the service class. If
query_working_mem and
target_query_working_mem are different, a dynamic
WLM transition is in process.
A value of -1 indicates than Auto WLM is configured. |
| target_query_working_mem | integer | The amount of working memory, in MB per slot, per node, set by the most recent WLM configuration change. |
| min_step_mem | integer | Reserved for system use. |
| name | character(64) | The name of the service class. |
| max_execution_time | bigint | Number of milliseconds that the query can run before being terminated. |
| user_group_wild_card | Boolean | If TRUE, the WLM queue treats an
asterisk (*) as a wildcard character in user group strings in the
WLM configuration. |
| query_group_wild_card | Boolean | If TRUE, the WLM queue treats an
asterisk (*) as a wildcard character in query group strings in the
WLM configuration. |
| concurrency_scaling | character(20) | Describes if the concurrency scaling is on or off. |
| query_priority | character(20) | The value of the query priority. |
| user_role_wild_card | Boolean | If TRUE, the WLM queue treats an
asterisk (*) as a wildcard character in user user strings in the
WLM configuration. |
Sample query
The first user-defined service class is service class 6, which is named Service class #1. The following query displays the current configuration for service classes greater than 4. For a list of service class IDs, see WLM service class IDs.
select rtrim(name) as name, num_query_tasks as slots, query_working_mem as mem, max_execution_time as max_time, user_group_wild_card as user_wildcard, query_group_wild_card as query_wildcard from stv_wlm_service_class_config where service_class > 4; name | slots | mem | max_time | user_wildcard | query_wildcard -----------------------------+-------+-----+----------+---------------+--------------- Service class for super user | 1 | 535 | 0 | false | false Queue 1 | 5 | 125 | 0 | false | false Queue 2 | 5 | 125 | 0 | false | false Queue 3 | 5 | 125 | 0 | false | false Queue 4 | 5 | 627 | 0 | false | false Queue 5 | 5 | 125 | 0 | true | true Default queue | 5 | 125 | 0 | false | false
The following query shows the status of a dynamic WLM transition. While the
transition is in process, num_query_tasks and
target_query_working_mem are updated until they equal the target
values. For more information, see WLM dynamic and static configuration
properties.
select rtrim(name) as name, num_query_tasks as slots, target_num_query_tasks as target_slots, query_working_mem as memory, target_query_working_mem as target_memory from stv_wlm_service_class_config where num_query_tasks > target_num_query_tasks or query_working_mem > target_query_working_mem and service_class > 5; name | slots | target_slots | memory | target_mem ------------------+-------+--------------+--------+------------ Queue 3 | 5 | 15 | 125 | 375 Queue 5 | 10 | 5 | 250 | 125 (2 rows)