Describe core data concepts →hardMultiple ChoiceObjective-mapped

DP-900 Describe core data concepts Practice Question

Exhibit

Refer to the exhibit.
-- Kusto Query
StormEvents
| where State == "FLORIDA"
| summarize TotalDamage = sum(DamageProperty) by EventType
| top 5 by TotalDamage desc

Refer to the exhibit. You are analyzing a Kusto query in Azure Data Explorer. The query is intended to return the top 5 event types that caused the most property damage in Florida. However, the query returns an error. What is the most likely cause?

⚠ Common exam trap

Watch out — candidates often assume the error is due to a syntax or operator misuse (like top needing order by or sum being invalid), when in reality the error stems from a simple schema mismatch—a common oversight when reading queries without verifying the underlying data model.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

The table or column names are incorrect.

The query returns an error because the table or column names referenced in the query do not match the actual schema in Azure Data Explorer. In Kusto Query Language (KQL), if a table name like 'Events' or a column like 'PropertyDamage' does not exist in the database, the query will fail with a 'semantic error' indicating an unknown table or column. This is the most likely cause given that the query logic (where, summarize, top) is syntactically correct.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The where clause must specify a numeric value.
Why it's wrong here
The where clause filters records using a Boolean predicate and can compare string columns to string literals without any numeric requirement. For instance, `where State == 'FLORIDA'` is perfectly valid, and KQL supports case-sensitive matches via `==`, plus operators like `contains` and `startswith`. The query's error cannot stem from the absence of a numeric value in the where clause.
✗
The summarize operator cannot use sum aggregation.
Why it's wrong here
The summarize operator groups rows and applies aggregation functions, and `sum()` is a standard, built-in KQL function for totaling numeric column values. It is equally valid to use `sum` alongside `count()`, `avg()`, `min()`, and `max()` in a summarize clause. Thus, the presence of `sum` in the summarize section is not the source of the reported failure.
✓
The table or column names are incorrect.
Why this is correct
A Kusto query that uses structurally valid operators will fail with a semantic recognition error when it references a table or column that does not exist in the current database or schema. Since the syntax of where, summarize, and top is correct, the most plausible cause is a misspelled table name or an incorrect column name (e.g., a missing quotation mark or wrong casing). Verify the exact schema from the Azure Data Explorer or Log Analytics schema pane to resolve the issue.
✗
The top operator requires an order by clause.
Why it's wrong here
The top operator has an optional `by` clause: `top 5 by Timestamp` orders rows before selecting the first five, but `top 5` without `by` simply returns the first five rows from the pipeline's current order. KQL does not require an explicit order by for top to execute, so the absence of an order-by clause is not an error. The query could run with top alone, producing nondeterministic results, but that is not the cause of the reported issue.

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DP-900 Describe core data concepts Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

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