By: Kyler Stole TrueCar’s Model Search offers a search results page (SRP) for virtual vehicle models. Combinable filters help you narrow down your vehicle needs to specific models that have what you want. This page was actually preceded by Vehicle Rankings pages, which also filter down models but then rank the results using TrueCar’s proprietary scoring system. When we ported…
#aggregation
6 posts
1 Mar 2023
11 Sept 2019
Using the right data type for some calculation sounds like some obvious advice. There are many blogs about using temporal data types for temporal data, instead of strings. An obvious reason is data integrity and correctness. We don’t gain much in storing dates as 2019-09-10 in one record, and as Nov 10, 2019 in the … Continue reading Oracle’s BINARY_DOUBLE…
25 May 2018
The SQL standard knows a lesser known feature called GROUPING SETS. One particular side-effect of that feature is that we can group by “nothing” in SQL. E.g. when querying the Sakila database: This will yield: count | ------| 1000 | What’s the point, you’re asking? Can’t we just omit the GROUP BY clause? Of course, … Continue reading How to…
27 May 2016
A common myth in SQL is the idea that correlated subqueries are evil and slow. For example, this query here: It “forces” the database engine to run a nested loop of the form (in pseudo code): So, for every actor, collect all the corresponding film_actors and count them. This will produce the number of films … Continue reading Correlated Subqueries…
5 May 2015
In the recent past, we’ve explained the syntactic implications of the SQL GROUP BY clause. If you haven’t already, you should read our article “Do You Really Understand SQL’s GROUP BY and HAVING clauses?“. In essence, adding a GROUP BY clause to your query transforms your query on very implicit levels. The following reminder summarises … Continue reading How SQL…
23 Jan 2015
I couldn’t resist. I have read this question by Hugo Prudente on Stack Overflow. And I knew there had to be a better way than what the JDK has to offer. The question reads: I’m looking for a lambda to refine the data already retrieved. I have a raw resultset, if the user do not … Continue reading How to…