Imperative Loop or Functional Stream Pipeline? Beware of the Performance Impact!

I like weird, yet concise language constructs and API usages https://twitter.com/nipafx/status/1055451667079008256 Yes. I am guilty. Evil? Don't know. But guilty. I heavily use and abuse the java.lang.Boolean type to implement three valued logic in Java: Boolean.TRUE means true (duh) Boolean.FALSE means false null can mean anything like "unknown" or "uninitialised", etc. I know - a … Continue reading Imperative Loop or Functional Stream Pipeline? Beware of the Performance Impact!

Writing Custom Aggregate Functions in SQL Just Like a Java 8 Stream Collector

All SQL databases support the standard aggregate functions COUNT(), SUM(), AVG(), MIN(), MAX(). Some databases support other aggregate functions, like: EVERY() STDDEV_POP() STDDEV_SAMP() VAR_POP() VAR_SAMP() ARRAY_AGG() STRING_AGG() But what if you want to roll your own? Java 8 Stream Collector When using Java 8 streams, we can easily roll our own aggregate function (i.e. a … Continue reading Writing Custom Aggregate Functions in SQL Just Like a Java 8 Stream Collector