EXPLAIN ANALYZE for actual execution in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show the actual execution plan of a query.

PostgreSQL

EXPLAIN [1] SELECT * FROM employees;

Drag options to blanks, or click blank then click option'

AANALYZE

BPLAN

CQUERY

DEXECUTE

Attempts:

3 left

💡 Hint

Common Mistakes

Using EXPLAIN PLAN instead of EXPLAIN ANALYZE.

Using EXPLAIN EXECUTE which is not valid.

The EXPLAIN ANALYZE command runs the query and shows the actual execution plan with timing.

2fill in blank

medium

Complete the code to get the execution time of a SELECT query on the products table.

PostgreSQL

EXPLAIN ANALYZE SELECT [1] FROM products WHERE price > 100;

Drag options to blanks, or click blank then click option'

Aid

Bprice

C*

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting only one column limits the plan details.

Using column names instead of * when full output is needed.

Using * selects all columns, so the plan shows the full query execution.

3fill in blank

hard

Fix the error in the EXPLAIN ANALYZE command to run it correctly.

PostgreSQL

EXPLAIN ANALYZE [1] FROM orders;

Drag options to blanks, or click blank then click option'

ASELECT *

BDELETE

CUPDATE

DINSERT

Attempts:

3 left

💡 Hint

Common Mistakes

Using only FROM without SELECT causes syntax error.

Using DELETE or UPDATE without full statement.

The EXPLAIN ANALYZE command must be followed by a valid SELECT, INSERT, UPDATE, or DELETE statement. Here, SELECT * is correct to query the table.

4fill in blank

hard

Fill both blanks to explain and analyze a query that counts rows in the sales table.

PostgreSQL

EXPLAIN [1] SELECT COUNT([2]) FROM sales;

Drag options to blanks, or click blank then click option'

AANALYZE

Bprice

C*

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using a column name inside COUNT instead of * counts only non-null values.

Omitting ANALYZE shows only estimated plan, not actual execution.

Use ANALYZE to run the query and get actual execution details. Use * inside COUNT to count all rows.

5fill in blank

hard

Fill all three blanks to explain and analyze a query that selects names and filters by age in the users table.

PostgreSQL

EXPLAIN [1] SELECT name FROM users WHERE age [2] [3];

Drag options to blanks, or click blank then click option'

AANALYZE

B>

C30

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > changes the filter logic.

Omitting ANALYZE shows only estimated plan.

Use ANALYZE to run the query and get real execution info. The condition age > 30 filters users older than 30.