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JOINs in SQL — Combining Tables Like a Pro
What You Will Learn Why JOINs exist and what they solve The four JOIN types: INNER, LEFT, RIGHT, FULL How to read a JOIN query line by line How…
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SQL GROUP BY Explained With Real Sales Data
What You Will Learn What GROUP BY does and why it is so important How to group by one column and by multiple columns The HAVING clause — filte…
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SQL Aggregations — COUNT, SUM, AVG, MIN, MAX Explained
What You Will Learn The five core SQL aggregation functions How each one handles NULL values Using DISTINCT inside aggregations How aggregation…
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How Containers Work Under the Hood — Namespaces and Cgroups
What You'll Learn Intermediate The three Linux kernel features that make containers possible How namespaces provide isolation How cgroups p…