I have an app that retrieves 640 data points from a Postgres database with a two-table join. The join was taking about 3 minutes to return results, so I decided to see if that could be improved. I examined the query plans and added a distinct clause to the query. This dropped the query response time […]
I have an app that retrieves 640 data points from a database (from the Series table) that are then rendered to JSON and sent to the client to be plotted on a chart. Active Record assembles an object from one or more database records. Since the Series class includes the Instrument class, each Series object […]
When we use a relational database, we are using database transactions. By default, every SQL statement (select, insert, update, etc.) executes within its own transaction. A transaction incurs a lot of overhead. When we need to process lots of SQL statements at a time, our application’s performance can suffer greatly. Background A database transaction represents […]
The goal of this project was to create an app using as much of what we have learned as possible. It needed to utilize React and Redux, ES6 syntax, and communicate with a Rails backend. I chose to write a stock portfolio valuation tool similar to what you’d see on Yahoo Finance, or at an […]