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Suffix Array Construction in Java
Searching the same text for new substrings can get expensive fast if you start from scratch every time.
14 hrs ago
•
Alexander Obregon
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Expression Indexes in SQL Queries
Databases run into this problem whenever a query filters on lower(email), on a date pulled from a timestamp, or on something derived from two columns.
May 5
•
Alexander Obregon
Weekly Recap – May 3rd, 2026
More Spring Boot, LeetCode, Java and SQL
May 4
•
Alexander Obregon
LeetCode #511 Game Play Analysis I - Solved in Pandas
Sort by Date and Keep the First Row and Group by Player and Take the Minimum Date
May 1
•
Alexander Obregon
Line Sweep Algorithms in Java
Sweep-based algorithms help with problems where the answer changes only at certain positions, not at every point between them.
May 1
•
Alexander Obregon
LeetCode #511 Game Play Analysis I - Solved in Oracle SQL
Correlated MIN Subquery and GROUP BY with MIN
Apr 30
•
Alexander Obregon
Request Coalescing in Spring Boot for Hot Cache Keys
Traffic spikes expose one of the hardest moments in a cache-aside flow.
Apr 29
•
Alexander Obregon
LeetCode #511 Game Play Analysis I - Solved in PostgreSQL
Correlated Subquery for the First Login and Group By With MIN
Apr 29
•
Alexander Obregon
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Alexander Obregon's Substack
Weekly recaps of what I’ve published, plus updates, extras, and some exclusive content you won’t find on my Medium.
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