Statements Page

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Note:

On a secure cluster you must be an admin user to access this area of the DB Console. See DB Console security.

The Statements page offers two views on statements: Statement Fingerprints, which represents one or more completed SQL statements; and Active Executions, which represents individual statement executions in progress.

Choose a view by selecting the Statement Fingerprints or Active Executions radio button. The selection is retained when you switch between the Statements and Transactions tabs on the SQL Activity page.

Tip:

If you haven't yet executed any queries in the cluster as a user, this page will be blank.

Statement Fingerprints view

The Statements Fingerprints view helps you:

To view this page, click SQL Activity in the left-hand navigation of the DB Console.

The Statements tab is selected. The Statement Fingerprints radio button is selected and the Statements table displays.

The following screenshot shows the statement fingerprint for SELECT city, id FROM vehicles WHERE city = $1 while running the movr workload:

Statement fingerprint

If you click the statement fingerprint in the Statements column, the Statement Fingerprint page displays.

Statement details

Active Executions view

New in v22.2: The Active Executions view helps you:

  • Understand and tune workload performance, particularly for long-running statements.

To display this view, click SQL Activity in the left-hand navigation of the DB Console.

The Statements tab is selected. Click the Active Executions radio button. The Active Executions table displays.

Note:

Active executions are polled every 10 seconds. Faster-running executions will potentially disappear upon each refresh.

The following screenshot shows the active statement execution for SELECT city, id FROM vehicles WHERE city = 'washington dc' while running the movr workload:

Statement execution

If you click the execution ID in the Statement Execution ID column, the Statement Execution details page displays.

Statement execution details

Search and filter

By default, the Statements page shows SQL statements from all applications and databases running on the cluster.

Search statements

To search using the search field:

  1. Type a string over Search Statements. To search for exact terms in order, wrap the search string in quotes.
  2. Press Enter.

    The list of statements is filtered by the string.

Time interval

To view statement fingerprints within a specific time interval, click the time interval selector and pick an interval. The time interval field supports preset time intervals (1 Hour, 6 Hours, 1 Day, etc.) and custom time intervals. To select a custom time interval, click the time interval field and select Custom time interval. In the Start (UTC) and End (UTC) fields select or type a date and time.

Use the arrow keys to cycle through previous and next time intervals. When you select a time interval, the same interval is selected in the Metrics page.

It's possible to select an interval for which no statement statistics exist. CockroachDB persists statement statistics up to 1 million rows before the oldest row is deleted. The retention period of statistics is reduced the more active a workload is and the more distinct statement fingerprints there are.

Filter

To filter the statements:

  1. Click the Filters field.

    • To filter by application, select App and select one or more applications.

      • Queries from the SQL shell are displayed under the $ cockroach app.
      • If you haven't set application_name in a client connection string, it appears as unset.
    • To filter by one or more databases (Database), SQL statement types (Statement Type), or nodes on which the statement ran (Node), click the field and select one or more checkboxes.

      The Statement Type values map to the CockroachDB statement types data definition language (DDL), data manipulation language (DML), data control language (DCL), and transaction control language (TCL).

    • To display only statement fingerprints that take longer than a specified time to run, specify the time and units.

    • To display only statement fingerprints with queries that cause full table scans, click Only show statements that contain queries with full table scans.

  2. Click Apply.

The following screenshot shows the statements that contain the string rides for the movr application:

Movr rides statements

Statement statistics

Statistics aggregation is controlled by the sql.stats.aggregation.interval cluster setting, set to 1 hour by default.

Aggregated statistics are flushed from memory to statistics tables in the crdb_internal system catalog every 10 minutes. The flushing interval is controlled by the sql.stats.flush.interval cluster setting.

The default retention period of the statistics tables is based on the number of rows up to 10 million records. When this threshold is reached, the oldest records are deleted. The diagnostics.forced_sql_stat_reset.interval cluster setting controls when persisted statistics are deleted only if the internal cleanup service experiences a failure.

To reset SQL statistics in the DB Console UI and crdb_internal system catalog, click clear SQL stats.

Example

See View historical statement statistics and the sampled logical plan per fingerprint.

SQL statement fingerprints

The Statements page displays SQL statement fingerprints.

A statement fingerprint represents one or more SQL statements by replacing literal values (e.g., numbers and strings) with underscores (_). This can help you quickly identify frequently executed SQL statements and their latencies.

For multiple SQL statements to be represented by a fingerprint, they must be identical aside from their literal values and placeholders.

These SQL statements:

  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES (380, 11, 11098)
  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES (192, 891, 20)
  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES (784, 452, 78)

have the fingerprint INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES (_, _, _)

These SQL statements:

  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES ($1, $2, 11098)
  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES ($3, $4, 300)

have the fingerprint INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES ($1, $1, _).

The following statements are not represented by either fingerprint:

  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES ($1, 11, 11098)
  • INSERT INTO new_order(product_id, customer_id, transaction_id) VALUES ($1, $2, $3)

It is possible to see the same fingerprint listed multiple times in the following scenarios:

  • Statements with this fingerprint were executed by more than one application_name.
  • Statements with this fingerprint were executed both successfully and unsuccessfully.

Statements table

Click Column selector to select the columns to display in the table.

The Statements table gives details for each SQL statement fingerprint:

Column Description
Statements SQL statement fingerprint. To view additional details, click the SQL statement fingerprint to open its Statement Fingerprint page.
Execution Count Cumulative number of executions of statements with this fingerprint within the time interval.

The bar indicates the ratio of runtime success (gray) to retries (red) for the SQL statement fingerprint.
Database The database in which the statement was executed.
Application Name The name specified by the application_name session setting. Click the name to view all statements run by that application.
Rows Processed Average number of rows read and written while executing statements with this fingerprint within the time interval.
Bytes Read Aggregation of all bytes read from disk across all operators for statements with this fingerprint within the time interval.

The gray bar indicates the mean number of bytes read from disk. The blue bar indicates one standard deviation from the mean. Hover over the bar to display exact values.
Statement Time Average planning and execution time of statements with this statement fingerprint within the time interval.

The gray bar indicates the mean latency. The blue bar indicates one standard deviation from the mean. Hover over the bar to display exact values.
Contention Time Average time statements with this fingerprint were in contention with other transactions within the time interval.

The gray bar indicates mean contention time. The blue bar indicates one standard deviation from the mean. Hover over the bar to display exact values.
Max Memory Maximum memory used by a statement with this fingerprint at any time during its execution within the time interval.

The gray bar indicates the average max memory usage. The blue bar indicates one standard deviation from the mean. Hover over the bar to display exact values.
Network Amount of data transferred over the network for statements with this fingerprint within the time interval. If this value is 0, the statement was executed on a single node.

The gray bar indicates the mean number of bytes sent over the network. The blue bar indicates one standard deviation from the mean. Hover over the bar to display exact values.
Retries Cumulative number of automatic (internal) retries by CockroachDB of statements with this fingerprint within the time interval.
% of All Runtime How much time this statement fingerprint took to execute compared to all other statements that were executed within the time period. It is expressed as a percentage. The runtime is the mean execution latency multiplied by the execution count.
Regions/Nodes The regions and nodes on which statements with this fingerprint executed.

Regions/Nodes is not visible for CockroachDB serverless clusters.
Diagnostics Activate and download diagnostics for this fingerprint. To activate, click the Activate button. The Activate statement diagnostics dialog displays. After you complete the dialog, the column displays the status of diagnostics collection (WAITING, READY, or ERROR). Click Vertical ellipsis and select a bundle to download or select Cancel request to cancel diagnostics bundle collection.

Statements are periodically cleared from the Statements page based on the start time. To access the full history of diagnostics for the fingerprint, see the Diagnostics tab of the Statement Details page.

Diagnostics is not visible for CockroachDB serverless clusters.
Last Execution Time (UTC) The timestamp when the statement was last executed.
Statement Fingerprint ID The ID of the statement fingerprint.
Note:

To obtain the execution statistics, CockroachDB samples a percentage of the executions. If you see no samples displayed in the Contention, Max Memory, or Network columns, there are two possibilities: - Your statement executed successfully but wasn't sampled because there were too few executions of the statement. - Your statement has failed (the most likely case). You can confirm by clicking the statement and viewing the value for Failed?.

To view statement details, click a SQL statement fingerprint in the Statements column to open the Statement Fingerprint page.

Statement Fingerprint page

The details displayed on the Statement Fingerprint page reflect the time interval selected on the Statements page.

Overview

The Overview section displays the SQL statement fingerprint and execution attributes:

  • Nodes: The nodes on which the statements executed. Click a node ID to view node statistics. Nodes are not displayed for CockroachDB serverless clusters.
  • Regions: The regions on which the statements executed. Regions are not displayed for CockroachDB serverless clusters.
  • Database: The database on which the statements executed.
  • Application Name: The name specified by the application_name session setting. Click the name to view all statements run by that application.
  • Failed?: Whether the statement failed to execute.
  • Full scan?: Whether the execution performed a full scan of the table.
  • Vectorized execution?: Whether the execution used the vectorized execution engine.
  • Transaction type: The type of transaction (implicit or explicit).
  • Last execution time: The timestamp when the statement was last executed.

The following screenshot shows the statement fingerprint of the query described in Use the right index:

Statement fingerprint overview

Charts

Charts following the execution attributes display statement fingerprint statistics:

  • Statement Execution and Planning Time: The time taken by the planner to create an execution plan and for CockroachDB to execute statements.
  • Rows Processed: The total number of rows read and written.
  • Execution Retries: The number of retries.
  • Execution Count: The total number of executions. It is calculated as the sum of first attempts and retries.
  • Contention Time: The amount of time spent waiting for resources.

The following charts summarize the executions of the statement fingerprint illustrated in Overview:

Statement fingerprint charts

Explain Plans

The Explain Plans tab displays statement plans for an explainable statement in the selected time interval. You can use this information to optimize the query. For more information about plans, see EXPLAIN.

The following screenshot shows an execution of the query discussed in Overview:

Plan table

The plan table shows the following details:

Column Description
Plan Gist A sequence of bytes representing the flattened tree of operators and operator-specific metadata of the statement plan.
Insights The number of insights for the plan. To configure when to trigger insights, see Schema insights settings.
Last Execution Time The timestamp when the statement was last executed.
Average Execution Time The average execution time for all the executions of the plan.
Execution Count The number of times the plan was executed.
Average Rows Read The average number of rows read when the plan was executed.
Full Scan Whether the execution performed a full scan of the table.
Distributed Whether the execution was distributed.
Vectorized Whether the execution used the vectorized execution engine.

To display the plan that was executed, click the plan gist. For the plan gist AgHUAQIABQAAAAHYAQIAiA..., the following plan displays:

Plan table

Insights

New in v22.2: The plan table displays the number of insights related to the plan. If a plan has at least 1 insight, when you click the plan gist, a table of insights that describe how to improve the performance will follow the plan.

The following screenshot shows 1 insight found after running the query discussed in Overview 6 or more times:

Plan with insight

Note:

CockroachDB uses the threshold of 6 executions before offering an insight because it assumes that you are no longer merely experimenting with a query at that point.

In this case the insight is recommending that you create an index on the start_time column of the rides table and storing the rider_id.

If you click Create Index, a confirmation dialog displays a warning about the cost of online schema changes and a button to copy the SQL statement for later execution in a SQL client.

If you click Apply to create the index and then execute the statement again, the Explain Plans tab will show that the second execution (in this case at 19:40), which uses the index and has no insight, takes less time than the first 6 executions.

Plan table after index

Diagnostics

The Diagnostics tab allows you to activate and download diagnostics for a SQL statement fingerprint.

Note:

The Diagnostics tab is not visible:

  • On CockroachDB serverless clusters.
  • For roles with the VIEWACTIVITYREDACTED role option.

When you activate diagnostics for a fingerprint, CockroachDB waits for the next SQL query that matches this fingerprint to be run on any node. On the next match, information about the SQL statement is written to a diagnostics bundle that you can download. This bundle consists of statement traces in various formats (including a JSON file that can be imported to Jaeger), a physical query plan, execution statistics, and other information about the query. The bundle contents are identical to those produced by EXPLAIN ANALYZE (DEBUG). You can use the information collected in the bundle to diagnose problematic SQL statements, such as slow queries. We recommend that you share the diagnostics bundle with our support team, which can help you interpret the results.

Tip:

Diagnostics will be collected a maximum of N times for a given activated fingerprint where N is the number of nodes in your cluster.

Warning:
Statement bundles can contain unredacted user data including histograms and placeholders that contain real data samples, statements that have real data which can contain PII information, and database schema that could be sensitive. Be careful when generating and sharing statement bundles.

To allow or disallow a role from seeing statements diagnostics bundles, set the VIEWACTIVITYREDACTED role option.

Activate diagnostics collection and download bundles

Activate statement diagnostics

To activate diagnostics collection:

  1. Click the Activate diagnostics button. The Activate statement diagnostics dialog displays.

    Statements diagnostics dialog

  2. Choose whether to activate collection on the next statement execution (default) or if execution latency exceeds a certain time. If you choose the latter, accept the default latency of 100 milliseconds, or specify a different time. All executions of the statement fingerprint will run slower until diagnostics are collected.

  3. Choose whether the request should expire after 15 minutes, or after a different the time, or disable automatic expiration by deselecting the checkbox.

  4. Click Activate.

A row with the activation time and collection status is added to the Statement diagnostics table.

Statement diagnostics table

The collection status values are:

  • READY: indicates that the diagnostics have been collected. To download the diagnostics bundle, click Down arrow Bundle (.zip).
  • WAITING: indicates that a SQL statement matching the fingerprint has not yet been recorded. To cancel diagnostics collection, click the Cancel request button.
  • ERROR: indicates that the attempt at diagnostics collection failed.

View and download diagnostic bundles for all statement fingerprints

Although fingerprints are periodically cleared from the Statements page, all diagnostics bundles are preserved. To view and download diagnostic bundles for all statement fingerprints, do one of the following:

  • On the Diagnostics tab for a statement fingerprint, click the All statement diagnostics link.

  • Click Advanced Debug in the left-hand navigation and click Statement Diagnostics History.

Click Down arrow Bundle (.zip) to download any diagnostics bundle.

See also

Active Executions table

Click Column selector to select the columns to display in the table.

Column Description
Statement Execution ID The execution ID of the statement execution.
Statement Execution The SQL statement that was executed.
Status The status of the execution: Preparing, Waiting, or Executing.
Start Time (UTC) The timestamp when the execution started.
Time Spent Waiting The time the execution spent waiting and experiencing lock contention.
Application The name specified by the application_name session setting.

To view details of an active statement execution, click an execution ID in the Statement Execution ID column to open the Statement Execution details page.

Statement execution details page

The statement execution details page provides the following details on the statement execution.

  • Start Time (UTC): The timestamp when the execution started.
  • Elapsed Time: The time elapsed since the execution started.
  • Status: The status of the execution: Preparing, Waiting, or Executing.
  • Full Scan: Whether the execution performed a full scan of the table.
  • Application Name: The name specified by the application_name session setting.
  • User Name: The name of the user running the statement.
  • Client Address: The IP address and port of the client that opened the session in which the statement is running.
  • Session ID: Link to the session in which the transaction is running.
  • Transaction Execution ID: Link to the ID of the transaction in which the statement is executing.

If a statement execution is waiting, the statement execution details are followed by Contention Insights and details of the statement execution on which the blocked statement execution is waiting.

Movr rides transactions

See also


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