ricardo lelis

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MySQL Row Generator like generate_series in PostgreSQL — just a simple view compatible with all MySQL versions.

Update 2017-05-23<p>MariaDB 10.2 introduced support for common table expressions.<p>Update 2018-04-19<p>MySQL 8.0 introduced support for common table …

Unittesting your indexes

During FOSDEM PGDay I watched the "Indexes: The neglected performance all-rounder" talk by Markus Winand. Both his talk and the "SQL Performance …

Fight against SQL injection attacks

Defend your sites against a common exploit<p>M. Tim Jones<br>Published on February 04, 2014<p>Given the general simplicity of Structured Query Language (SQL) …

Information Security

Myth: Select * is bad

Up to 100x slower when preventing an Index-Only Scan<p>Broadly speaking, the less columns you ask for, the less data must be loaded from disk when …

Response Time, Throughput and Horizontal Scalability

Bigger hardware is not always faster—but it can usually handle more load. Bigger hardware is more like a wider highway than a faster car: you cannot …

Use Subqueries to Count Distinct 50X Faster

<i>NB: These techniques are universal, but for syntax we chose Postgres. Thanks to the inimitable pgAdminIII for the Explain graphics.</i><p>So Useful, Yet So …

Databases