PostgreSQL on myblog http://blog.pdan.dev/tags/postgresql/ Recent content in PostgreSQL on myblog Hugo en-US Fri, 10 Oct 2025 21:29:01 +0800 Database Design http://blog.pdan.dev/posts/database-design/ Fri, 10 Oct 2025 21:29:01 +0800 http://blog.pdan.dev/posts/database-design/ <p>   </p> <p>   </p> <p>   </p> <p>   </p> <h2 id="database-design">Database Design</h2> <h3 id="oltp-and-olap">OLTP and OLAP</h3> <ul> <li> <p>How should we organize and manage data?</p> </li> <li> <p>Schemas: How should my data be logically organized?</p> </li> <li> <p>Normalization: Should my data have minimal dependency and redundancy?</p> </li> <li> <p>Views: What joins will be done most often?</p> </li> <li> <p>Access control: Should all users of the data have the same level of access?</p> </li> <li> <p>DBMS: How do I pick between all the SQL and NoSQL options?</p> </li> <li> <p>and more!</p> </li> </ul> <p>It depends on the intended use the date</p> PostgreSQL http://blog.pdan.dev/posts/postgresql/ Thu, 09 Oct 2025 21:29:01 +0800 http://blog.pdan.dev/posts/postgresql/ <p><img src="images/00.png" alt="img00"></p> <p>   </p> <p>   </p> <h2 id="postgresql-summary-stats-and-window-functions">PostgreSQL Summary stats and window functions</h2> <h3 id="introduction-to-windows-functions">Introduction to windows functions</h3> <p><img src="images/01.webp" alt="img01"></p> <p><img src="images/02.webp" alt="img02"></p> <p><img src="images/03.webp" alt="img03"></p> <p>   </p> <p>   </p> <h4 id="window-functions">Window functions</h4> <ul> <li> <p>Perform calculations across a set of table rows that are somehow related to the current row</p> </li> <li> <p>Similar to <code>GROUP BY</code> aggregation, but all rows remain in the output (no grouping)</p> </li> </ul> <p><strong>Uses</strong></p> <ul> <li> <p>Fetching values from preceding or following rows (e.g. fetching the previous row&rsquo;s value)</p> <ul> <li> <p>Determining reigning champion status</p> </li> <li> <p>Calculating growth over time</p> </li> </ul> </li> <li> <p>Assigning ordinal ranks (1st, 2nd, etc.) to rows based on their values&rsquo; positions in a sorted list</p>