GoLand 2020.2 Help

Create diagrams

Database diagrams graphically show the structure of the database and relations between database objects. You can generate a diagram for a data source, a schema, or a table. To create relations between database objects, consider using primary and foreign keys.

Also, you can build execution plans. Execution plan is a set of steps that were used to access data in a database. GoLand supports two types of execution plans:

  • Explain Plan: the result is shown in a mixed tree and table format on a dedicated Plan tab. You can click the Show Visualization icon (the Show Visualization icon) to create a diagram that visualizes the query execution.

  • Explain Plan (Raw): the result is shown in a table format.

Generate a diagram for a database object

  • In the Database tool window (View | Tool Windows | Database), right-click a database object and select Diagrams | Show Visualization.

Generate a diagram for a database object

Build a query plan

  1. Right-click an SQL statement, and select Explain Plan.

  2. In the Output pane, click Plan.

  3. By default, you see the tree representation of the query. To see the query plan, click Show Visualization the Show Visualization button, or press Ctrl+Alt+Shift+U.

Viewing SQL Query map

Show execution plans

  • To create an execution plan, right-click a query in the editor and select Explain Plan. If you want to create a diagram for the query, click the Show Visualization icon (the Show Visualization icon).

Showing an execution plan as a diagram

Enable column comments

  1. Generate a diagram. For more information about generating a diagram, see Generate a diagram for a database object.

  2. Click the Comments button (the Comments button).

    Enable column comments

Creating EXPLAIN query plan

The EXPLAIN command shows the execution plan of a statement. It means you can see details on the approach that the planner took to execute the statement. For example, how the tables are scanned, what join algorithms are used to bring together the required rows, statement execution costs, and other information.

Execution cost is the planner's guess at how long it takes to run the statement. The measurement is made in relative cost units. The execution cost has two options: start-up and total. The start-up cost shows how long it takes before the first row can be processed, while the total cost shows how long it takes to process all the rows.

If you use the ANALYZE option with EXPLAIN, the statement is actually executed, not only planned. In this case, you can see the run time statistics in milliseconds.

Generate a flame graph for EXPLAIN

  1. Right-click an SQL statement, and select Explain Plan.

  2. In the Output pane, click Plan.

  3. Click the Flame Graph icon (the Flame Graph icon) and select between the following options:

    • Total Cost: how long it takes to return all the rows

    • Startup Cost: how long it takes before the first row can be processed.

    Generate a flame graph for EXPLAIN

Generate a flame graph for EXPLAIN ANALYSE

  1. Right-click an SQL statement, and select Explain Analyse Plan.

  2. In the Output pane, click Plan.

  3. Click the Flame Graph icon (the Flame Graph icon) and select between the following options:

    • Total Cost: how long it takes to return all the rows (in relative cost units).

    • Actual Total Time: how long it takes to return all the rows (in milliseconds).

    • Startup Cost: how long it takes before the first row can be processed (in relative cost units).

    • Actual Startup Time: how long it takes before the first row can be processed (in milliseconds).

    Generate a flame graph for EXPLAIN ANALYSE
Last modified: 19 August 2020