{"appId":"sql-app","version":1551,"selectedAngularVersion":20,"item":{"id":"lesson-oltp-vs-olap","conceptKey":"oltp-vs-olap","subjectId":"subject-oltp-vs-olap","title":"OLTP vs OLAP","summary":"OLTP systems optimize frequent business transactions, while OLAP systems optimize analytical scans and aggregation.","baseContent":"<h2>OLTP vs OLAP</h2><p>OLTP systems optimize frequent business transactions, while OLAP systems optimize analytical scans and aggregation.</p><h3>Example</h3><pre><code>-- Apply OLTP vs OLAP to a small, testable schema.\nSELECT * FROM orders LIMIT 10;</code></pre><h3>Key point</h3><p>Use the smallest correct statement, test it with representative data, and verify constraints and performance before production use.</p><h3>Real-life example</h3><p>A retailer copies operational sales data into an analytics model so analysts can compare revenue by date, store, product, and customer segment.</p><h3>Advanced example</h3><pre><code>SELECT d.calendar_month, p.category, SUM(f.amount) AS revenue\nFROM sales_fact f\nJOIN date_dim d ON d.id = f.date_id\nJOIN product_dim p ON p.id = f.product_id\nGROUP BY d.calendar_month, p.category\nORDER BY d.calendar_month, revenue DESC;</code></pre><h3>Expected result</h3><p>The schema or operation satisfies the stated rule, rejects invalid data, and can be verified with a repeatable query.</p><h3>Production check</h3><ul><li>Test with empty, duplicate, null, and boundary values.</li><li>Use a transaction for related writes.</li><li>Inspect the execution plan before adding an index.</li><li>Use parameterized queries for application input.</li></ul><h3>Continue with the PicoStore database</h3><p>This lesson reuses <strong>picostore</strong>. Relevant tables: <code>orders, order_items, products, customers</code>. Keep the starter rows from the Introduction lesson so results remain comparable.</p><h3>Another practical example</h3><pre><code>SELECT o.order_id, c.name AS customer, o.status, o.total\nFROM orders o\nJOIN customers c ON c.customer_id = o.customer_id\nWHERE o.total &gt;= 1000\nORDER BY o.ordered_at DESC;</code></pre><h3>Check the result</h3><p>Run the verification query, compare the returned rows with the starter data, and explain why every included or excluded row is correct.</p><section data-nonversioned-curriculum=\"1\"><h3>Easy example</h3><p>Start with a small customer table and retrieve active customers in a predictable order.</p><pre><code>SELECT customer_id, name, email\nFROM customers\nWHERE status = 'active'\nORDER BY name;</code></pre><h3>How to verify the easy example</h3><ul><li>Run it with representative input.</li><li>Confirm the expected output.</li><li>Try one missing, invalid, or boundary value.</li></ul><h3>Advanced example</h3><p>Use a CTE and a window function to rank customer revenue while keeping the query readable and testable.</p><pre><code>WITH customer_revenue AS (\n  SELECT customer_id, SUM(total_amount) AS revenue\n  FROM orders\n  WHERE order_status = 'completed'\n  GROUP BY customer_id\n)\nSELECT customer_id, revenue,\n       DENSE_RANK() OVER (ORDER BY revenue DESC) AS revenue_rank\nFROM customer_revenue\nORDER BY revenue_rank, customer_id;</code></pre><h3>Advanced review</h3><ul><li>Explain the tradeoffs and assumptions.</li><li>Test failure, scale, security, and recovery behavior.</li><li>Capture evidence from tests, execution plans, logs, or review output.</li></ul><h3>Additional practical guidance</h3><div><h3>OLTP vs OLAP: MySQL and PostgreSQL</h3><p>The architecture applies to both engines, but replication, failover, materialized-view, and warehouse tooling is vendor-specific. Define consistency, recovery, and freshness requirements before choosing an implementation.</p><h3>Required verification</h3><ul><li>Run the simple case.</li><li>Test a NULL, duplicate, empty, or boundary case where relevant.</li><li>Confirm the affected rows or query result.</li><li>Use EXPLAIN for performance-sensitive queries.</li></ul></div></section>","detailId":"lesson-oltp-vs-olap-964153c6","versions":[],"isActive":true,"detailIsActive":true,"lessonVersions":[],"selectedVersion":20,"content":"","updatedAt":"2026-08-01T09:43:04.474Z","details":[{"id":"lesson-oltp-vs-olap","conceptKey":"oltp-vs-olap","subjectId":"subject-oltp-vs-olap","title":"OLTP vs OLAP","summary":"OLTP systems optimize frequent business transactions, while OLAP systems optimize analytical scans and aggregation.","baseContent":"<h2>OLTP vs OLAP</h2><p>OLTP systems optimize frequent business transactions, while OLAP systems optimize analytical scans and aggregation.</p><h3>Example</h3><pre><code>-- Apply OLTP vs OLAP to a small, testable schema.\nSELECT * FROM orders LIMIT 10;</code></pre><h3>Key point</h3><p>Use the smallest correct statement, test it with representative data, and verify constraints and performance before production use.</p><h3>Real-life example</h3><p>A retailer copies operational sales data into an analytics model so analysts can compare revenue by date, store, product, and customer segment.</p><h3>Advanced example</h3><pre><code>SELECT d.calendar_month, p.category, SUM(f.amount) AS revenue\nFROM sales_fact f\nJOIN date_dim d ON d.id = f.date_id\nJOIN product_dim p ON p.id = f.product_id\nGROUP BY d.calendar_month, p.category\nORDER BY d.calendar_month, revenue DESC;</code></pre><h3>Expected result</h3><p>The schema or operation satisfies the stated rule, rejects invalid data, and can be verified with a repeatable query.</p><h3>Production check</h3><ul><li>Test with empty, duplicate, null, and boundary values.</li><li>Use a transaction for related writes.</li><li>Inspect the execution plan before adding an index.</li><li>Use parameterized queries for application input.</li></ul><h3>Continue with the PicoStore database</h3><p>This lesson reuses <strong>picostore</strong>. Relevant tables: <code>orders, order_items, products, customers</code>. Keep the starter rows from the Introduction lesson so results remain comparable.</p><h3>Another practical example</h3><pre><code>SELECT o.order_id, c.name AS customer, o.status, o.total\nFROM orders o\nJOIN customers c ON c.customer_id = o.customer_id\nWHERE o.total &gt;= 1000\nORDER BY o.ordered_at DESC;</code></pre><h3>Check the result</h3><p>Run the verification query, compare the returned rows with the starter data, and explain why every included or excluded row is correct.</p><section data-nonversioned-curriculum=\"1\"><h3>Easy example</h3><p>Start with a small customer table and retrieve active customers in a predictable order.</p><pre><code>SELECT customer_id, name, email\nFROM customers\nWHERE status = 'active'\nORDER BY name;</code></pre><h3>How to verify the easy example</h3><ul><li>Run it with representative input.</li><li>Confirm the expected output.</li><li>Try one missing, invalid, or boundary value.</li></ul><h3>Advanced example</h3><p>Use a CTE and a window function to rank customer revenue while keeping the query readable and testable.</p><pre><code>WITH customer_revenue AS (\n  SELECT customer_id, SUM(total_amount) AS revenue\n  FROM orders\n  WHERE order_status = 'completed'\n  GROUP BY customer_id\n)\nSELECT customer_id, revenue,\n       DENSE_RANK() OVER (ORDER BY revenue DESC) AS revenue_rank\nFROM customer_revenue\nORDER BY revenue_rank, customer_id;</code></pre><h3>Advanced review</h3><ul><li>Explain the tradeoffs and assumptions.</li><li>Test failure, scale, security, and recovery behavior.</li><li>Capture evidence from tests, execution plans, logs, or review output.</li></ul><h3>Additional practical guidance</h3><div><h3>OLTP vs OLAP: MySQL and PostgreSQL</h3><p>The architecture applies to both engines, but replication, failover, materialized-view, and warehouse tooling is vendor-specific. Define consistency, recovery, and freshness requirements before choosing an implementation.</p><h3>Required verification</h3><ul><li>Run the simple case.</li><li>Test a NULL, duplicate, empty, or boundary case where relevant.</li><li>Confirm the affected rows or query result.</li><li>Use EXPLAIN for performance-sensitive queries.</li></ul></div></section>","detailId":"lesson-oltp-vs-olap-964153c6","versions":[],"isActive":true,"detailIsActive":true,"lessonVersions":[],"selectedVersion":20,"content":"","updatedAt":"2026-08-01T09:43:04.474Z"}]}}