Tag: SQL
All the articles with the tag "SQL".
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Extracting the last part of a string after a delimiter in SQL Server
· UpdatedGet the text after the last underscore in SQL Server with REVERSE + CHARINDEX, RIGHT or PARSENAME, and avoid the off-by-position and no-delimiter errors.
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Soda Core with SQL Server: connection, Windows auth, SSL errors and checks
· UpdatedConnect Soda Core to SQL Server: ODBC driver, SQL login or Windows auth, fixing SSL: CERTIFICATE_VERIFY_FAILED, and count-distinct checks in SodaCL.
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COALESCE doesn't care what your columns mean
COALESCE checks types, not meaning. How merging columns with different semantics silently breaks data, and the dbt guardrails that catch it.
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Window Functions vs JOIN in Spark: A Physical Plan Perspective
When solving analytical queries in Spark SQL, there are often multiple correct formulations. However, they do not produce equivalent execution plans. This article compares two approaches to the same
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Why Small Tables Can Explode: Understanding JOIN Cardinality in SQL
It is common to assume that joining two small tables will produce a small result set. In practice, this assumption frequently fails. Even tables with only a handful of rows can generate unexpectedly
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The History of Hive and Trino: From Hadoop to Lakehouses
The evolution of Big Data architectures is deeply tied to the history of two projects born at Facebook: Hive and Trino . Both emerged from real engineering pain points, but at different times and for
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Querying JSONB in PostgreSQL Efficiently
In modern applications, it is common to store semi-structured data in JSON format inside a relational database like PostgreSQL. However, to analyze this data properly, you need a way to transform it
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Understanding Window Functions in SQL: Beyond Simple Aggregations
When we think about SQL functions, we often start with scalar functions ( UPPER() , ROUND() , NOW() ) or aggregate functions ( SUM() , AVG() , COUNT() ). But there is a third type that is essential