Cost optimization strategies in Snowflake - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the warehouse size to a smaller option for cost savings.

Snowflake

ALTER WAREHOUSE my_warehouse SET WAREHOUSE_SIZE = '[1]';

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

A2X-Large

BLarge

CXSMALL

DMedium

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a larger warehouse size increases costs unnecessarily.

Using invalid warehouse size names causes errors.

Setting the warehouse size to 'XSMALL' reduces compute costs by using fewer resources.

2fill in blank

medium

Complete the code to enable auto-suspend after 5 minutes of inactivity.

Snowflake

ALTER WAREHOUSE my_warehouse SET AUTO_SUSPEND = [1];

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

A0

B600

C60

D300

Attempts:

3 left

💡 Hint

Common Mistakes

Setting AUTO_SUSPEND to 0 disables auto-suspend, increasing costs.

Using too long a suspend time delays cost savings.

Setting AUTO_SUSPEND to 300 seconds (5 minutes) helps save costs by suspending idle warehouses.

3fill in blank

hard

Fix the error in the query to limit data scanned for cost optimization.

Snowflake

SELECT * FROM sales_data WHERE transaction_date [1] '2023-01-01';

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

A>=

B==

C!=

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' is invalid in SQL for comparison.

Using '<>' or '!=' filters out the date, not what is needed.

Using '>=' filters data from 2023-01-01 onwards, reducing scanned data and cost.

4fill in blank

hard

Fill both blanks to create a clustering key on the 'customer_id' column for cost-efficient queries.

Snowflake

ALTER TABLE sales_data CLUSTER BY ([1]([2]));

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

AHASH

Bcustomer_id

CDATE

DRANGE

Attempts:

3 left

💡 Hint

Common Mistakes

Using DATE as a function causes syntax errors.

Clustering by wrong columns reduces effectiveness.

Using HASH(customer_id) clusters data by customer ID, improving query performance and reducing costs.

5fill in blank

hard

Fill all three blanks to create a materialized view that refreshes automatically to save compute costs.

Snowflake

CREATE MATERIALIZED VIEW [1] AS SELECT [2] FROM sales_data WHERE region = '[3]';

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

Amv_sales_region

BSUM(amount)

CUS

DCOUNT(*)

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNT(*) instead of SUM(amount) changes the aggregation meaning.

Incorrect region value causes no data to be stored.

Creating a materialized view named 'mv_sales_region' with SUM(amount) for region 'US' precomputes data, saving compute costs on repeated queries.

Practice

1. Which Snowflake feature helps reduce costs by automatically stopping a warehouse when it's not in use?

easy

A. Auto-suspend

B. Multi-cluster warehouse

C. Data sharing

D. Continuous data protection

Solution

1. Step 1: Understand warehouse billing

   Snowflake charges for compute resources while warehouses run, even if idle.

2. Step 2: Identify cost-saving feature

   Auto-suspend stops the warehouse after inactivity, preventing unnecessary charges.

3. Final Answer:

   Auto-suspend -> Option A

4. Quick Check:

   Auto-suspend = stops warehouse when idle [OK]

Hint: Auto-suspend pauses compute to save money when idle [OK]

Common Mistakes:

• Confusing auto-suspend with auto-resume
• Thinking multi-cluster reduces cost automatically
• Assuming data sharing affects compute cost

2. Which of the following is the correct syntax to set a warehouse to auto-suspend after 5 minutes in Snowflake?

easy

A. ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = '5 minutes';

B. ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = 5;

C. ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = 300;

D. ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = TRUE;

Solution

1. Step 1: Understand AUTO_SUSPEND unit

   Snowflake expects AUTO_SUSPEND value in seconds, so 5 minutes = 300 seconds.

2. Step 2: Check syntax correctness

   ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = 300; uses correct syntax and value (300 seconds). Others use wrong units or types.

3. Final Answer:

   ALTER WAREHOUSE my_wh SET AUTO_SUSPEND = 300; -> Option C

4. Quick Check:

   Auto-suspend time in seconds = 300 [OK]

Hint: Auto-suspend time is in seconds, not minutes [OK]

Common Mistakes:

• Using minutes instead of seconds
• Setting AUTO_SUSPEND to TRUE/FALSE
• Using string values instead of integers

3. Consider this Snowflake SQL snippet:

ALTER WAREHOUSE wh1 SET AUTO_SUSPEND = 600;
ALTER WAREHOUSE wh1 SET AUTO_RESUME = TRUE;

What is the effect on cost when no queries run for 15 minutes?

medium

A. Warehouse suspends after 10 minutes, no charges after that

B. Warehouse keeps running, charges continue for 15 minutes

C. Warehouse suspends immediately, no charges after query ends

D. Warehouse suspends after 15 minutes, charges continue until then

Solution

1. Step 1: Analyze AUTO_SUSPEND setting

   Warehouse suspends after 600 seconds (10 minutes) of inactivity.

2. Step 2: Understand AUTO_RESUME behavior

   Warehouse auto-resumes on new queries, but here no queries run for 15 minutes.

3. Step 3: Calculate cost impact

   Charges stop after suspension at 10 minutes; no charges for last 5 minutes idle.

4. Final Answer:

   Warehouse suspends after 10 minutes, no charges after that -> Option A

5. Quick Check:

   Auto-suspend 600s stops charges after 10 min idle [OK]

Hint: Auto-suspend time controls idle billing stop [OK]

Common Mistakes:

• Assuming warehouse suspends immediately after last query
• Thinking charges continue for full 15 minutes
• Confusing auto-resume with auto-suspend timing

4. You set a warehouse with AUTO_SUSPEND = 0 and AUTO_RESUME = TRUE. What issue might this cause?

medium

A. Warehouse auto-resume is disabled, queries fail

B. Warehouse never suspends, causing continuous charges

C. Warehouse suspends after default 10 minutes ignoring 0

D. Warehouse suspends immediately, causing query failures

Solution

1. Step 1: Understand AUTO_SUSPEND = 0 meaning

   Setting AUTO_SUSPEND to 0 disables suspension; warehouse runs continuously.

2. Step 2: Check AUTO_RESUME effect

   AUTO_RESUME TRUE allows auto start but does not suspend warehouse automatically.

3. Step 3: Identify cost impact

   Warehouse never suspends, so charges accrue continuously even if idle.

4. Final Answer:

   Warehouse never suspends, causing continuous charges -> Option B

5. Quick Check:

   AUTO_SUSPEND=0 means no suspend, costs continue [OK]

Hint: AUTO_SUSPEND=0 disables suspend, causing constant charges [OK]

Common Mistakes:

• Thinking 0 means immediate suspend
• Assuming AUTO_RESUME disables charges
• Believing default suspend time applies

5. A company wants to minimize Snowflake costs by scheduling warehouse usage only during business hours (9am-5pm). Which combination of strategies best achieves this?

hard

A. Set warehouse to always on and rely on auto-resume to start queries

B. Use multi-cluster warehouse to handle peak loads during business hours

C. Disable auto-suspend and manually suspend warehouse after hours

D. Use auto-suspend with 1-minute timeout and schedule warehouse start/stop tasks at 9am and 5pm

Solution

1. Step 1: Understand scheduling needs

   Warehouse should run only during business hours to save costs outside those times.

2. Step 2: Evaluate options

   Use auto-suspend with 1-minute timeout and schedule warehouse start/stop tasks at 9am and 5pm combines auto-suspend (quick suspend) and scheduled start/stop tasks to control usage precisely.

3. Step 3: Rule out other options

   Set warehouse to always on and rely on auto-resume to start queries wastes cost by always on; C is manual and error-prone; D increases cost for peak handling.

4. Final Answer:

   Use auto-suspend with 1-minute timeout and schedule warehouse start/stop tasks at 9am and 5pm -> Option D

5. Quick Check:

   Scheduled start/stop + auto-suspend = cost control [OK]

Hint: Schedule start/stop plus auto-suspend for tight cost control [OK]

Common Mistakes:

• Leaving warehouse always on wastes money
• Relying on manual suspend risks forgetting
• Using multi-cluster increases cost, not reduces