Updated on 2023-11-27 GMT+08:00

Real-Time Queries

Going to the Real-time Query Page

  1. Log in to the GaussDB(DWS) management console.
  2. On the Clusters page, locate the target cluster.
  3. In the Operation column of the target cluster, click Monitoring Panel.
  4. In the navigation pane, choose Monitoring > Queries.

    You can check the real-time information about all queries and sessions running in the cluster.

  • Real-time query is supported only in clusters of version 8.1.2 and later.

Prerequisites

You need to set GUC parameters before viewing data on the monitoring page. If GUC parameters are not set, real-time or historical query may be unavailable. However, if this parameter is set, the cluster performance may deteriorate. Therefore, you need to balance the settings of related parameters. The following table describes recommended settings. For details about how to modify parameters, see Modifying Database Parameters. Setting GUC Parameters provides parameter details.

Table 1 Recommended GUC parameter settings

GUC Parameter

CN Configuration

DN Configuration

max_active_statements

10

10

enable_resource_track

on

on

resource_track_level

query

query

resource_track_cost

0

0

resource_track_duration

10

10

enable_resource_record

on

on

session_statistics_memory

1000MB

1000MB

Querying Information

You can view the queries statistics, the number of sessions, average session duration, number of queries, average query duration, and average query waiting time.

Checking Live Sessions

On the Sessions tab, you can browse the real-time information about all running queries,

  • Session ID
  • Username
  • Session duration
  • Application name
  • QueryBand
  • Client IP address
  • Connected CN
  • Session status. It can be:
    • idle: The backend is waiting for new client commands.
    • active: The backend is executing queries.
    • idle in transaction: The backend is in a transaction, but there is no statement being executed in the transaction.
    • idle in transaction (aborted): The backend is in a transaction, but there are statements failed in the transaction.
    • fastpath function call: The backend is executing a fast-path function.
  • Start time
  • Lock mode
  • Lock holding status
  • Locked object
  • Query SQL
  • Lock wait
  • Current query duration
  • Current query start time
  • You can click a session ID to view the queries in the current session. For details, see Viewing Historical Query Monitoring Details.
  • To terminate a session, select the session, click Terminate a Session, and confirm your operation.
  • The fine-grained permission control function is added. Only users with the operate permission are able to terminate sessions. For users with the read-only permission, the Terminate a Session button is grayed out.

Checking Real-time Queries

On the Queries tab, you can browse all the queries that are running in a specified time period, including:

  • Query ID
  • Username
  • Database name
  • Submission time
  • Execution time
  • Statement
  • Lane
  • Query status. It can be:
    • idle: The backend is waiting for new client commands.
    • active: The backend is executing queries.
    • idle in transaction: The backend is in a transaction, but there is no statement being executed in the transaction.
    • idle in transaction (aborted): The backend is in a transaction, but there are statements failed in the transaction.
    • fastpath function call: The backend is executing a fast-path function.
  • You can click a query ID to view the monitoring details. However, details cannot be displayed for queries whose ID is 0. Query 0 indicates that an exception occurs during the query.
  • To terminate a query, select the query, click Terminate Query, and confirm your operation.
  • The fine-grained permission control function is added. Only users with the operate permission are able to terminate queries. For users with the read-only permission, the Terminate Query button is grayed out.

Viewing Real-time Query Monitoring Details

You can click a query ID to view the query details, including the basic information of query statements, real-time and historical resource consumption, SQL description, and query plan.