Interview › Databases & Caching
What is the difference between OLTP and OLAP workloads?
Databases & Caching · Intermediate level
Answer
OLTP workloads serve many small, concurrent transactions with low latency and strong correctness. OLAP workloads serve analytical scans, aggregations, and reports over large historical data, so heavy OLAP should usually be isolated from the OLTP primary.
Technical explanation
OLTP is optimized for short, indexed, concurrent transactions; OLAP is optimized for large scans, joins, and aggregations.
Running OLAP reports on the OLTP primary can consume I/O, CPU, buffers, and locks needed by user traffic.
Common designs isolate analytics through read replicas, CDC pipelines, warehouses, materialized views, or summary tables.
Hands-on example
Example separation:
Checkout API reads/writes orders on the primary RDS instance.
Monthly revenue report runs on a warehouse fed by CDC.
Immediate mitigation for a heavy reporting user:
ALTER ROLE reporting_user SET statement_timeout = "5min";
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