Part_III_Analysis_on_maps Data generation Generate 500 points, roughly on circle of radius 1. Jitter x and y by +/-0.25: SELECT ST_MakePoint( Cos(2 * Pi() * d / 500.0) -- x * (1 + Random() * 0.5 - 0.25), -- jitter-x Sin(2 * Pi() * d / 500.0) -- y * (1 + Random() * 0.5 - 0.25) -- jitter-y ) as wkb_geometry FROM generate_series(0, 500) d; Create a synthetic star ratings table: CREATE TABLE ratings A
Java, SQL and jOOQ. Best Practices and Lessons Learned from Writing Awesome Java and SQL Code. Get some hands-on insight on what's behind developing jOOQ. Listicles like these do work – not only do they attract attention, if the content is also valuable (and in this case it is, trust me), the article format can be extremely entertaining. This article will bring you 10 SQL tricks that many of you m
PostgreSQL 9.3 has a new join type! Lateral joins arrived without a lot of fanfare, but they enable some powerful new queries that were previously only tractable with procedural code. In this post, I’ll walk through a conversion funnel analysis that wouldn’t be possible in PostgreSQL 9.2. Interested in learning more about Heap Engineering? Meet our team to get a feel for what it’s like to work at
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The DENSE_RANK window function determines the rank of a value in a group of values, based on the ORDER BY expression in the OVER clause. If the optional PARTITION BY clause is present, the rankings are reset for each group of rows. Rows with equal values for the ranking criteria receive the same rank. The DENSE_RANK function differs from RANK in one respect: if two or more rows tie, there is no ga
Opaleye’s sugar on top SQL in the type system where it belongs People often talk of how solutions fall naturally into place when we program in Haskell and embrace its type system. This article walks us through that process, serving as a gentle introduction to some practical uses of advanced features of the Haskell type system within the context of Opaleye and SQL. I invite you to continue reading
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