Refactor lesson post and enhance styling: update content structure and improve code block appearance

Author: mag1cfrog

docs/_posts/2025-06-13-first-lesson.md

@@ -5,19 +5,34 @@ categories:
   - spark
   - optimization
 tags:
-  - broadcast
-  - partitioning
   - performance
 excerpt: "How switching from partitioned joins to broadcast joins reduced shuffle writes from 8GB to 500MB"
 ---
 
-## First Lesson: Partition vs Broadcast
 
-When joining a large 10 GB DataFrame with a small 200 MB lookup table, I discovered that:
 
-- Using a **broadcast join** with `spark.conf.set("spark.sql.autoBroadcastJoinThreshold", "300MB")` dropped shuffle write from 8 GB to 500 MB.
-- Conversely, relying on default partitioned joins caused redundant shuffles across executors.
+We have a Spark job on Databricks that would join a enormous table (player tracking records of coordindates on frames) with a dimensional table (position number to player uid mapping), and then do some de-dup using window function.
+
+## The Deduplication Challenge
+
+The core logic involved a window function to handle duplicate records (some psedudo SQL):
+
+```sql
+WITH ranked AS (
+  SELECT 
+    tracking.*,
+    lineup.fielder_id,
+    lineup.position_alpha,
+    ROW_NUMBER() OVER (
+      PARTITION BY game_id, pitch_uid, position_num, event_time
+      ORDER BY processed_year DESC, processed_month DESC, processed_day DESC
+    ) AS rn
+  FROM hawkeye_tracking tracking
+  JOIN hawkeye_lineup lineup ON (...)
+)
+SELECT * EXCEPT (rn)
+FROM ranked 
+WHERE rn = 1
+```
+
 
-<aside class="callout">
-💡 **Tip:** Always tune `spark.sql.shuffle.partitions = executors * cores_per_executor` after switching join strategies.
-</aside>

docs/assets/css/style.css

@@ -5,11 +5,35 @@ body {
   margin: auto;
   padding: 1rem;
 }
-pre {
-  background: #f5f5f5;
-  padding: 0.5rem;
-  overflow-x: auto;
+
+/* Override the theme's pre styling with more specific selectors */
+.content pre[class*="language-"] {
+  background: #f5f5f5 !important;
+  border: 1px solid #e0e0e0 !important;
+  border-radius: 6px !important;
+  padding: 1em !important;
+  margin: 1.5em 0 !important;
+  line-height: 1.5 !important;
 }
+
+/* Also target the code element inside pre */
+.content pre[class*="language-"] code {
+  background: none !important;
+  padding: 0 !important;
+  color: #333333 !important;
+  font-size: 0.9em !important;
+}
+
+/* Fallback for any plain pre tags */
+.content pre:not([class]) {
+  background: #f5f5f5 !important;
+  border: 1px solid #e0e0e0 !important;
+  border-radius: 6px !important;
+  padding: 1em !important;
+  margin: 1.5em 0 !important;
+  line-height: 1.5 !important;
+}
+
 .callout {
   border-left: 4px solid #007acc;
   background: #f0f8ff;