A/B Testing Database Storage Calculator FAQ
Answers to common questions about estimating annual A/B test database storage, event records, overhead, and capacity planning.
This FAQ explains what the annual A/B testing database storage estimate includes, how its inputs affect the result, and where additional infrastructure capacity may be needed.
General calculator questions
Basic information about what the estimate measures.
What does the A/B Testing Database Storage (Annual) Calculator estimate?
It estimates one year of primary database storage for experiment assignments, retained experiment events, basic test metadata, and a selected storage overhead allowance.
Who can use this calculator?
It can be used by product, analytics, data engineering, and experimentation teams that need a rough capacity estimate for retained A/B test data.
Is the result shown in GB or TB?
The calculator returns both decimal GB and decimal TB. One TB is equal to 1,000 GB in this estimate.
Does it measure database performance?
No. It estimates data capacity, not query speed, ingestion throughput, memory requirements, or compute demand.
Inputs and record volume
How visitor, test, and event inputs create the estimated record count.
What counts as a participant record?
A participant record is an experiment assignment or exposure record created when a visitor is included in a test.
Can the same visitor be counted in multiple tests?
Yes. The calculation assumes a visitor included in multiple experiments can create a separate participant record for each experiment.
What does traffic included per test mean?
It is the share of monthly visitors that typically enters an experiment. For example, 50% means half of the available visitors are included in each test.
Why do events per participant matter so much?
Every retained event creates a row or payload. Multiplying event count by participant volume can quickly produce a large amount of data.
Should the control be included in average variants?
Yes. Enter all variants, including the control. For example, one control and two treatments equals three variants.
Storage calculation and overhead
How raw storage and the final capacity estimate are formed.
How is event payload storage calculated?
Annual event records are multiplied by average event size in KB, converted to bytes, and then expressed in decimal GB.
What is included in assignment storage?
It represents the estimated stored size of assignment or exposure records across all experiment participants.
How much metadata storage is included?
The calculation allows approximately 50 KB of configuration and metadata per test variant. This is usually small compared with event storage.
What does database overhead include?
It is an adjustable allowance for items such as indexes, row headers, free space, and capacity headroom. Its real-world scope depends on the database implementation.
Can I set overhead to zero?
Yes, but that produces a raw-data estimate and may understate practical database capacity requirements.
Accuracy and planning scope
Important limits and additional capacity considerations.
Does the estimate include backups?
No. Separate backup copies are not included and should be planned independently.
Does it include replicas and disaster recovery storage?
No. Replicas, disaster recovery copies, transaction logs, and exports may need additional capacity beyond this estimate.
Will compression reduce the result?
Potentially. Compression can change physical storage use, but the calculator does not assume a specific compression ratio.
What if events are deleted after 90 days?
If raw events are retained for less than a year, live database storage may be lower. Use the calculator as a full-year retention estimate unless you adjust the inputs or calculate retention separately.
Is this a guaranteed storage requirement?
No. It is an estimate based on supplied averages. Actual usage depends on schemas, retention, indexing, partitioning, database behavior, and operational design.
What does this calculator estimate?
It estimates annual primary database storage for A/B test assignment records, retained events, basic metadata, and selected database overhead.
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