Performance — the jumping problem — too many database (or something else) calls

var result = GetResultsFromDatabase();
foreach(var row in result)
var otherResult = GetOtherResultFromDatabase(row);
//Do something
  1. Retrieve the first 100 sales and, for each sale, retrieve it’s respective vendor;
  2. Retrieve the first 100 sales and its vendor together.
  • Jumps to the database: 101
    1 jump to retrieve firsts 100 sales and + 1 each vendor.
  • Time spent on the database: 187583 ms
  • Jumps to the database: 1
    1 jump to retrieve the joined query.
  • Time spent on the database: 45094 ms
  1. These times are on my machine;
  2. The database are fully available for my application;
  3. Numbers of columns selected can also affect this time;
  4. Could be cases where it’s slowly to retrieve all information joined, it depends on the scenario, indexes, tecnologies and so on;
  5. Could be cases where a business logic prevent the use of such thing.

Reproduce it yourself:

cd /path/to/copy/of/repository
mkdir postgres_data
docker-compose build
docker-compose up -d
  1. The profiler display 101 records reads in the first line and 2 on the others because, I guess, the rows counts as one or more and it’s metadata counts as plus one;
  2. It’s mandatory to use Entity Framework to display the query on the profiler (or Source here;




Software Performance Engineer wannabe

Love podcasts or audiobooks? Learn on the go with our new app.

Recommended from Medium

Heap Sort

Manage granular permissions using IAM Policies

Introduction of Compass


Akka as a bridge between REST and Kafka

Zomato App development — The Agile Way

Best Tool To Turn Scans Into Audio In 2022

Is There Any Free Web Content Classification?

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Glauber Cini

Glauber Cini

Software Performance Engineer wannabe

More from Medium

Display 3D Model using Window Presentation Foundation

In-Memory and Distributed cache (.NET Core)

Setup your CI/CD pipeline with Configuration as a Code and GitHub Actions in 1 minute.

Fixing my BF1942 woes with Win32 APIs