Help Center/ GaussDB(DWS)/ SQL Syntax Reference/ SQL Syntax Reference (8.1.3.x)/ Functions and Operators/ System Administration Functions/ Resource Management Functions
Updated on 2024-09-03 GMT+08:00
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Resource Management Functions

This section describes the functions of the resource management module.

gs_wlm_readjust_user_space(oid)

Description: This function calibrates the permanent storage space of a user. The input parameter is the user OID. If the input parameter is set to 0, the permanent storage space of all users is calibrated.

Return type: text

Example:

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SELECT gs_wlm_readjust_user_space(0);
gs_wlm_readjust_user_space
----------------------------
Exec Success
(1 row)

pgxc_wlm_readjust_schema_space()

Description: This function calibrates the permanent storage space of a schema.

Return type: text

Example:

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SELECT pgxc_wlm_readjust_schema_space();
pgxc_wlm_readjust_schema_space
--------------------------------
Exec Success
(1 row)

pgxc_wlm_readjust_relfilenode_size_table()

Description: Space statistics calibration function. It does not recreate the PG_RELFILENODE_SIZE system catalog but recalibrates the user and schema space.

Due to transaction isolation between the calibration function and other services, the calibration function is invisible to other services that are being executed. As a result, the calibration function does not involve space changes of such services. To avoid space difference errors after calibration, you are advised to use the space calibration function to perform calibration when the space is stable.

Return type: text

Example:

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SELECT pgxc_wlm_readjust_schema_space();
pgxc_wlm_readjust_relfilenode_size_table
-----------------------------------------
Exec Success
(1 row)

pgxc_wlm_readjust_relfilenode_size_table(integer)

Description: Space statistics calibration function

Due to transaction isolation between the calibration function and other services, the calibration function is invisible to other services that are being executed. As a result, the calibration function does not involve space changes of such services. To avoid space difference errors after calibration, you are advised to use the space calibration function to perform calibration when the space is stable.

Parameter: The value ranges from 0 to 4. Different input parameter values indicate different calibration granularities.

  • If the input parameter is set to 0 (default value), the PG_RELFILENODE_SIZE system catalog is not rebuilt and the user and schema space are recalibrated.
  • If the input parameter is set to 1, the PG_RELFILENODE_SIZE system catalog is rebuilt and the user and schema space are recalibrated.
  • If the input parameter is set to 2, the PG_RELFILENODE_SIZE system catalog is rebuilt.
  • If the input parameter is set to 3, the schema space is recalibrated.
  • If the input parameter is set to 4, the user space is recalibrated.

Return type: text

Example:

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SELECT * FROM  pgxc_wlm_readjust_relfilenode_size_table(1);
    result
--------------
 Exec success
(1 row)

pgxc_wlm_get_schema_space(cstring)

Description: Obtains the schema space of each instance in a specified logical cluster on the CN.

Return type: record

The following table describes return columns.

Column

Type

Description

schemaname

text

Schema name

schemaid

oid

Schema OID

databasename

text

Database name

databaseid

oid

Database OID

nodename

text

Instance name

nodegroup

text

Name of the node group

usedspace

bigint

Size of the used space

permspace

bigint

Upper limit of the space

Examples:

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SELECT * FROM pgxc_wlm_get_schema_space('group1');
     schemaname     | schemaid | databasename | databaseid |   nodename   |  nodegroup   | usedspace | permspace
--------------------+----------+--------------+------------+--------------+--------------+-----------+-----------
 pg_catalog         |       11 | test1        |      16384 | datanode1    | installation |   9469952 |        -1
 public             |     2200 | postgres     |      15253 | datanode1    | installation |  25280512 |        -1
 pg_toast           |       99 | test1        |      16384 | datanode1    | installation |   1859584 |        -1
 cstore             |      100 | test1        |      16384 | datanode1    | installation |         0 |        -1
 data_redis         |    18106 | postgres     |      15253 | datanode1    | installation |    655360 |        -1
 data_redis         |    18116 | test1        |      16384 | datanode1    | installation |         0 |        -1
 public             |     2200 | test1        |      16384 | datanode1    | installation |     16384 |        -1
 dbms_om            |     3987 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_job           |     3988 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_om            |     3987 | test1        |      16384 | datanode1    | installation |         0 |        -1
 dbms_job           |     3988 | test1        |      16384 | datanode1    | installation |         0 |        -1
 sys                |    11693 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 sys                |    11693 | test1        |      16384 | datanode1    | installation |         0 |        -1
 utl_file           |    14644 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 utl_raw            |    14669 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_sql           |    14674 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_output        |    14662 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_random        |    14666 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 dbms_lob           |    14701 | postgres     |      15253 | datanode1    | installation |         0 |        -1
 information_schema |    14300 | postgres     |      15253 | datanode1    | installation |    294912 |        -1
 information_schema |    14300 | test1        |      16384 | datanode1    | installation |    294912 |        -1
 utl_file           |    14644 | test1        |      16384 | datanode1    | installation |         0 |        -1
 dbms_output        |    14662 | test1        |      16384 | datanode1    | installation |         0 |        -1
 dbms_random        |    14666 | test1        |      16384 | datanode1    | installation |         0 |        -1
 utl_raw            |    14669 | test1        |      16384 | datanode1    | installation |         0 |        -1
 dbms_sql           |    14674 | test1        |      16384 | datanode1    | installation |         0 |        -1
 dbms_lob           |    14701 | test1        |      16384 | datanode1    | installation |         0 |        -1
 pg_catalog         |       11 | postgres     |      15253 | datanode1    | installation |  13049856 |        -1
 redisuser          |    16387 | postgres     |      15253 | datanode1    | installation |    630784 |        -1
 pg_toast           |       99 | postgres     |      15253 | datanode1    | installation |   3080192 |        -1
 cstore             |      100 | postgres     |      15253 | datanode1    | installation |   2408448 |        -1
 pg_catalog         |       11 | test1        |      16384 | datanode2    | installation |   9469952 |        -1
 public             |     2200 | postgres     |      15253 | datanode2    | installation |  25214976 |        -1
 pg_toast           |       99 | test1        |      16384 | datanode2    | installation |   1859584 |        -1
 cstore             |      100 | test1        |      16384 | datanode2    | installation |         0 |        -1
 data_redis         |    18106 | postgres     |      15253 | datanode2    | installation |    655360 |        -1
 data_redis         |    18116 | test1        |      16384 | datanode2    | installation |         0 |        -1
 public             |     2200 | test1        |      16384 | datanode2    | installation |     16384 |        -1
 dbms_om            |     3987 | postgres     |      15253 | datanode2    | installation |         0 |        -1
 dbms_job           |     3988 | postgres     |      15253 | datanode2    | installation |         0 |        -1
 dbms_om            |     3987 | test1        |      16384 | datanode2    | installation |         0 |        -1
 dbms_job           |     3988 | test1        |      16384 | datanode2    | installation |         0 |        -1

pgxc_wlm_analyze_schema_space(cstring)

Description: Obtains the schema space of a specified logical cluster on the CN.

Return type: record

The following table describes return columns.

Column

Type

Description

schemaname

text

Schema name

databasename

text

Database name

nodegroup

text

Name of the node group

total_value

bigint

Total cluster space in the current schema

avg_value

bigint

Average space of instances in the current schema

skew_percent

integer

Skew ratio

extend_info

text

Extended information, including the maximum space of a single instance, minimum space of a single instance, and names of the instances with the maximum space or minimum space

Examples:

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SELECT * FROM pgxc_wlm_analyze_schema_space('group1');
     schemaname     | databasename |  nodegroup   | total_value | avg_value | skew_percent |                  extend_info
--------------------+--------------+--------------+-------------+-----------+--------------+-----------------------------------------------
 pg_catalog         | test1        | installation |    56819712 |   9469952 |            0 | min:9469952 datanode1,max:9469952 datanode1
 public             | postgres     | installation |   150495232 |  25082538 |            0 | min:24903680 datanode6,max:25280512 datanode1
 pg_toast           | test1        | installation |    11157504 |   1859584 |            0 | min:1859584 datanode1,max:1859584 datanode1
 cstore             | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 data_redis         | postgres     | installation |     1966080 |    327680 |           50 | min:0 datanode4,max:655360 datanode1
 data_redis         | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 public             | test1        | installation |       98304 |     16384 |            0 | min:16384 datanode1,max:16384 datanode1
 dbms_om            | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_job           | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_om            | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_job           | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 sys                | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 sys                | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 utl_file           | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 utl_raw            | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_sql           | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_output        | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_random        | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_lob           | postgres     | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 information_schema | postgres     | installation |     1769472 |    294912 |            0 | min:294912 datanode1,max:294912 datanode1
 information_schema | test1        | installation |     1769472 |    294912 |            0 | min:294912 datanode1,max:294912 datanode1
 utl_file           | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_output        | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_random        | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 utl_raw            | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_sql           | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 dbms_lob           | test1        | installation |           0 |         0 |            0 | min:0 datanode1,max:0 datanode1
 pg_catalog         | postgres     | installation |    75431936 |  12571989 |            3 | min:12124160 datanode4,max:13049856 datanode1
 redisuser          | postgres     | installation |     1884160 |    314026 |           50 | min:16384 datanode4,max:630784 datanode1
 pg_toast           | postgres     | installation |    17154048 |   2859008 |            7 | min:2637824 datanode4,max:3080192 datanode1
 cstore             | postgres     | installation |    15294464 |   2549077 |            5 | min:2408448 datanode1,max:2703360 datanode6
(31 rows)

gs_wlm_set_queryband_action(cstring,cstring,int4)

Description: Sets the action and query order of query_band.

Return type: boolean

The following table describes the input parameters.

Name

Type

Description

qband

cstring

Query band key-value pair. The maximum length is 63 characters.

action

cstring

Action associated to a query band

order

int4

Query band query order. The default value is -1.

Examples:

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SELECT * FROM gs_wlm_set_queryband_action('a=1','respool=p1');
 gs_wlm_set_queryband_action
-----------------------------
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(1 row)
SELECT * FROM gs_wlm_set_queryband_action('a=3','respool=p1;priority=rush',1);
 gs_wlm_set_queryband_action
-----------------------------
 t
(1 row)

gs_wlm_set_queryband_order(cstring,int4)

Description: Sets the query_band query order.

Return type: boolean

The following table describes the input parameters.

Name

Type

Description

qband

cstring

query_band key-value pairs

order

int4

query_band query order. The default value is -1.

Examples:

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SELECT * FROM gs_wlm_set_queryband_order('a=1',2);
 gs_wlm_set_queryband_action
-----------------------------
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(1 row)

gs_wlm_get_queryband_action(cstring)

Description: Obtains the action and query order of query_band.

Return type: record

The following table describes return columns.

Column

Type

Description

qband

cstring

query_band key-value pairs

respool_id

Oid

OID of the resource pool associated with query_band

respool

text

Name of the resource pool associated with query_band

priority

text

Intra-queue priority associated with query_band

qborder

int4

query_band query order

Examples:

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SELECT * FROM gs_wlm_get_queryband_action('a=1');
qband | respool_id | respool | priority | qborder
-------+------------+---------+----------+---------
 a=1   |      16388 | p1      | Medium   |      -1
(1 row)

gs_cgroup_reload_conf()

Description: This function loads the Cgroup configuration file online on the current instance.

Return type: record

The following table describes return columns.

Column

Type

Description

node_name

text

Instance name

node_host

text

IP address of the node where the instance is located

result

text

Whether Cgroup online loading is successful

Examples:

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SELECT * FROM gs_cgroup_reload_conf();
 node_name |   node_host    | result
-----------+----------------+---------
 cn_5001   | 192.168.178.35 | success

pgxc_cgroup_reload_conf()

Description: This function loads the Cgroup configuration file online on all instances of the system.

Return type: record

The following table describes return columns.

Column

Type

Description

node_name

text

Instance name

node_host

text

IP address of the node where the instance is located

result

text

Whether Cgroup online loading is successful

Examples:

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SELECT * FROM pgxc_cgroup_reload_conf();
  node_name   |    node_host    | result
--------------+-----------------+---------
 dn_6025_6026 | 192.168.178.177 | success
 dn_6049_6050 | 192.168.179.79  | success
 dn_6051_6052 | 192.168.179.79  | success
 dn_6055_6056 | 192.168.179.79  | success
 dn_6067_6068 | 192.168.181.57  | success
 dn_6023_6024 | 192.168.178.39  | success
 dn_6009_6010 | 192.168.181.21  | success
 dn_6011_6012 | 192.168.181.21  | success
 dn_6015_6016 | 192.168.181.21  | success
 dn_6029_6030 | 192.168.178.177 | success
 dn_6031_6032 | 192.168.178.177 | success
 dn_6045_6046 | 192.168.179.45  | success
 cn_5001      | 192.168.178.35  | success
 cn_5003      | 192.168.178.39  | success
 dn_6061_6062 | 192.168.181.179 | success
 cn_5006      | 192.168.179.45  | success
 cn_5004      | 192.168.178.177 | success
 cn_5002      | 192.168.181.21  | success
 cn_5005      | 192.168.178.187 | success
 dn_6019_6020 | 192.168.178.39  | success
 dn_6007_6008 | 192.168.178.35  | success
 dn_6071_6072 | 192.168.181.57  | success
 dn_6003_6004 | 192.168.178.35  | success
 dn_6013_6014 | 192.168.181.21  | success
 dn_6035_6036 | 192.168.178.187 | success
 dn_6037_6038 | 192.168.178.187 | success
 dn_6001_6002 | 192.168.178.35  | success
 dn_6063_6064 | 192.168.181.179 | success
 dn_6005_6006 | 192.168.178.35  | success
 dn_6057_6058 | 192.168.181.179 | success
 dn_6069_6070 | 192.168.181.57  | success
 dn_6027_6028 | 192.168.178.177 | success
 dn_6059_6060 | 192.168.181.179 | success
 dn_6041_6042 | 192.168.179.45  | success
 dn_6043_6044 | 192.168.179.45  | success
 dn_6047_6048 | 192.168.179.45  | success
 dn_6033_6034 | 192.168.178.187 | success
 dn_6065_6066 | 192.168.181.57  | success
 dn_6021_6022 | 192.168.178.39  | success
 dn_6017_6018 | 192.168.178.39  | success
 dn_6039_6040 | 192.168.178.187 | success
 dn_6053_6054 | 192.168.179.79  | success
(42 rows)

pgxc_cgroup_reload_conf(text)

Description: This function loads the Cgroup configuration file online on a node. The input parameter is the IP address of the node.

Return type: record

The following table describes return columns.

Column

Type

Description

node_name

text

Instance name

node_host

text

IP address of the node where the instance is located

result

text

Whether Cgroup online loading is successful

Examples:

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SELECT * FROM pgxc_cgroup_reload_conf('192.168.178.35');
  node_name   |   node_host    | result
--------------+----------------+---------
 cn_5001      | 192.168.178.35 | success
 dn_6007_6008 | 192.168.178.35 | success
 dn_6003_6004 | 192.168.178.35 | success
 dn_6001_6002 | 192.168.178.35 | success
 dn_6005_6006 | 192.168.178.35 | success
(5 rows)

gs_wlm_node_recover(boolean isForce)

Description: Updates and restores job information and counts on the CCN in dynamic resource management mode. This function can be executed only by administrators, and is usually used to restore a faulty CN after it was restarted. This function is called by the Cluster Manager (CM). Its usages are as follows:

  • If this function is executed by CN, it instructs the CCN to clear job information and counts on the CN.
  • If this function is executed by CCN, it resets job counts and obtains the latest slow lane job information from the CN.

Return type: bool

gs_wlm_node_clean(cstring nodename)

Description: On the CCN in dynamic resource management mode, clears the job information and counts of a specified CN. This function can be executed only by administrators, and is usually used to restore a faulty CN after it was restarted. This function is called by the Cluster Manager (CM). Generally, users are not advised to call it.

Return type: bool

pg_stat_get_wlm_node_resource_info(int4)

Description: Displays the summary of all DN resources.

Return type: record

The following table describes return columns.

Column

Type

Description

min_mem_util

integer

Minimum memory usage of a DN

max_mem_util

integer

Maximum memory usage of a DN

min_cpu_util

integer

Minimum CPU usage of a DN

max_cpu_util

integer

Maximum CPU usage of a DN

min_io_util

integer

Minimum I/O usage of a DN

max_io_util

integer

Maximum I/O usage of a DN

phy_usemem_rate

integer

Maximum physical memory usage

pg_stat_get_workload_struct_info()

Description: Load management function for locating CCN queuing problems. This function is an internal function. To use this function, contact technical support engineers.

Return type: record