Franck Pachot
@franckpachot.bsky.social
https://dev.to/franckpachot
🥑 Developer Advocate at 🍃 MongoDB
🔸 AWS Data Hero
🅾️ Oracle Certified Master
🐘 PostgreSQL and▝▞ YugabyteDB
🥑 Developer Advocate at 🍃 MongoDB
🔸 AWS Data Hero
🅾️ Oracle Certified Master
🐘 PostgreSQL and▝▞ YugabyteDB
Scalable database: query response time stays consistent as data grows. A simple query to compare MongoDB with emulations - typical OLTP with filter, sort, and pagination: dev.to/franckpachot...
How does it scale? A basic OLTP benchmark on MongoDB
Choosing a database requires ensuring that performance remains fast as your data grows. For example,...
dev.to
November 11, 2025 at 6:07 PM
Scalable database: query response time stays consistent as data grows. A simple query to compare MongoDB with emulations - typical OLTP with filter, sort, and pagination: dev.to/franckpachot...
I've never realized before that SQL*Plus can tell you when it disconnects "with complications" 🤓
November 7, 2025 at 7:15 PM
I've never realized before that SQL*Plus can tell you when it disconnects "with complications" 🤓
B‑trees face issues like page splits, locks, and buffer pins. LSM‑trees avoid them but raise write amplification. WiredTiger takes a third path: lock‑free B‑trees with hazard pointers for reads and skip lists for writes. Great article on the #MongoDB blog:
www.mongodb.com/company/blog...
www.mongodb.com/company/blog...
To Lock or Not: MongoDB’s Lock-Free B-Tree Unlocks Throughput
Learn how MongoDB's WiredTiger lock-free B+tree, using hazard pointers and skip lists, boosts read and write throughput for better hardware utilization.
www.mongodb.com
November 7, 2025 at 6:07 PM
B‑trees face issues like page splits, locks, and buffer pins. LSM‑trees avoid them but raise write amplification. WiredTiger takes a third path: lock‑free B‑trees with hazard pointers for reads and skip lists for writes. Great article on the #MongoDB blog:
www.mongodb.com/company/blog...
www.mongodb.com/company/blog...
I'm curious if some @oracleace.bsky.social will be attending AWS re:Invent, given the multi-cloud partnership. Asking because there'll be an event open to advocates, heroes, champions, builders, ambassadors, and user group leaders to celebrate community leaders and meet
November 7, 2025 at 5:41 PM
I'm curious if some @oracleace.bsky.social will be attending AWS re:Invent, given the multi-cloud partnership. Asking because there'll be an event open to advocates, heroes, champions, builders, ambassadors, and user group leaders to celebrate community leaders and meet
Developers — curious to know how you document data model relationships today?
www.linkedin.com/posts/franck...
www.linkedin.com/posts/franck...
Developers — curious to know how you document data model relationships today?
🟥 ERDs are common for relational databases, but they don’t tell the whole story: inheritance, how many is “many” in a… | F...
Developers — curious to know how you document data model relationships today?
🟥 ERDs are common for relational databases, but they don’t tell the whole story: inheritance, how many is “many” in a one‑...
www.linkedin.com
November 6, 2025 at 9:42 AM
Developers — curious to know how you document data model relationships today?
www.linkedin.com/posts/franck...
www.linkedin.com/posts/franck...
An example of a covering index to avoid fetching large documents in a MongoDB aggregation pipeline
dev.to/franckpachot...
dev.to/franckpachot...
Covering index for $group/$sum in MongoDB aggregation (with hint)
MongoDB indexes enable quick equality and range filtering (with $match) and ordering (with $sort)....
dev.to
November 5, 2025 at 9:30 PM
An example of a covering index to avoid fetching large documents in a MongoDB aggregation pipeline
dev.to/franckpachot...
dev.to/franckpachot...
I enjoy staying connected with multiple database communities. Even if I share more about one today 🌱🐅, I'm happy to have feedback from others 🅾️🔸️🐘🐬 on what I share
October 30, 2025 at 9:51 AM
I enjoy staying connected with multiple database communities. Even if I share more about one today 🌱🐅, I'm happy to have feedback from others 🅾️🔸️🐘🐬 on what I share
Sad times where tech giant billionaires fire people to build datacenters in a giant game of Monopoly
From an Amazon Employees for Climate Justice statement:
“They’re pushing this narrative that AI is transformative and that’s why they’re making these cuts. But leadership is spending 100 billion this year alone on the new data centers; they have to find that money elsewhere,” said one AWS engineer.
“They’re pushing this narrative that AI is transformative and that’s why they’re making these cuts. But leadership is spending 100 billion this year alone on the new data centers; they have to find that money elsewhere,” said one AWS engineer.
October 29, 2025 at 7:32 AM
Sad times where tech giant billionaires fire people to build datacenters in a giant game of Monopoly
A migration tool vendor suggests that migration is necessary for improved consistency, reliability, and advanced query capabilities. Yet, success often comes from first understanding your current database. Questioning these claims is the occasion to learn:
dev.to/franckpachot...
dev.to/franckpachot...
Advanced Query Capabilities 👉🏻 aggregation pipelines
Although MongoDB has supported ACID transactions and sophisticated aggregation features for years,...
dev.to
October 22, 2025 at 7:46 PM
A migration tool vendor suggests that migration is necessary for improved consistency, reliability, and advanced query capabilities. Yet, success often comes from first understanding your current database. Questioning these claims is the occasion to learn:
dev.to/franckpachot...
dev.to/franckpachot...
I'm curious to find out whether Oracle still uses DerbyDB in their Oracle Database Appliances to store the metadata, and what they will replace it with
October 16, 2025 at 10:13 AM
I'm curious to find out whether Oracle still uses DerbyDB in their Oracle Database Appliances to store the metadata, and what they will replace it with
More WiredTiger internals: persisting MongoDB's committed MVCC versions through checkpoints and restarts dev.to/franckpachot...
WiredTigerHS.wt: MongoDB MVCC Durable History Store
MongoDB uses the WiredTiger storage engine, which implements Multi‑Version Concurrency Control (MVCC)...
dev.to
September 29, 2025 at 9:01 AM
More WiredTiger internals: persisting MongoDB's committed MVCC versions through checkpoints and restarts dev.to/franckpachot...
Reposted by Franck Pachot
Trust me I was so against it when I arrived at spark I’ve used it in the past and hated it.
but the lack of relations is actually amazing for backfill. it just makes it so simple and painless that I’m willing to live with the mongo of it all
but the lack of relations is actually amazing for backfill. it just makes it so simple and painless that I’m willing to live with the mongo of it all
September 28, 2025 at 3:14 AM
Trust me I was so against it when I arrived at spark I’ve used it in the past and hated it.
but the lack of relations is actually amazing for backfill. it just makes it so simple and painless that I’m willing to live with the mongo of it all
but the lack of relations is actually amazing for backfill. it just makes it so simple and painless that I’m willing to live with the mongo of it all
Reposted by Franck Pachot
Blog post for September 2025
SQL Developer isn't entirely CBO-friendly.
jonathanlewis.wordpress.com/2025/09/24/s...
SQL Developer isn't entirely CBO-friendly.
jonathanlewis.wordpress.com/2025/09/24/s...
September 24, 2025 at 12:29 PM
Blog post for September 2025
SQL Developer isn't entirely CBO-friendly.
jonathanlewis.wordpress.com/2025/09/24/s...
SQL Developer isn't entirely CBO-friendly.
jonathanlewis.wordpress.com/2025/09/24/s...
A closer look at MongoDB Text Search: which terms are indexed for a string, how they're stored, and what formula is used to calculate the query's matching score. Since it's based on Lucene, let's use Lucene tools. dev.to/franckpachot...
MongoDB Search Index Internals with Luke (Lucene Toolbox GUI tool)
Previously, I demonstrated MongoDB text search scoring with a simple example, creating a dynamic...
dev.to
September 22, 2025 at 2:31 PM
A closer look at MongoDB Text Search: which terms are indexed for a string, how they're stored, and what formula is used to calculate the query's matching score. Since it's based on Lucene, let's use Lucene tools. dev.to/franckpachot...
An example of MongoDB aggregation pipeline compared to the equivalent in SQL/JSON with common table expressions (CTE), from a StackOverflow question: dev.to/franckpachot...
Combine Two JSON Collections with Nested Arrays: MongoDB and PostgreSQL Aggregations
Suppose you need to merge two sources of data—both JSON documents containing nested arrays. This was...
dev.to
September 18, 2025 at 7:40 AM
An example of MongoDB aggregation pipeline compared to the equivalent in SQL/JSON with common table expressions (CTE), from a StackOverflow question: dev.to/franckpachot...
A flexible schema permits arrays in fields without upfront declaration, and filters and indexes (multiple keys per document) use it automatically. MongoDB tracks multikey paths in indexed fields to optimize index scans:
dev.to/franckpachot...
dev.to/franckpachot...
MongoDB Multikey Indexes and Index Bound Optimization
Previously, I discussed how MongoDB keeps track of whether indexed fields contain arrays. This...
dev.to
September 16, 2025 at 4:53 PM
A flexible schema permits arrays in fields without upfront declaration, and filters and indexes (multiple keys per document) use it automatically. MongoDB tracks multikey paths in indexed fields to optimize index scans:
dev.to/franckpachot...
dev.to/franckpachot...
MongoDB’s strength is not only in its flexible, document-oriented API, but also in its ability to store documents to disk without random I/O slicing or vacuuming later. Here's how MongoDB persists collections and indexes in WiredTiger:
dev.to/franckpachot...
dev.to/franckpachot...
MongoDB Internals: How Collections and Indexes Are Stored in WiredTiger
WiredTiger is MongoDB’s default storage engine, but what really occurs behind the scenes when...
dev.to
September 15, 2025 at 7:10 AM
MongoDB’s strength is not only in its flexible, document-oriented API, but also in its ability to store documents to disk without random I/O slicing or vacuuming later. Here's how MongoDB persists collections and indexes in WiredTiger:
dev.to/franckpachot...
dev.to/franckpachot...
For nearly a decade, MongoDB provided reliable persistence with one of the most robust storage engines. Yet somehow, the oldest jokes keep persisting, too, so here are some facts:
dev.to/franckpachot...
dev.to/franckpachot...
Resilience of MongoDB's WiredTiger Storage Engine to Disk Failure Compared to PostgreSQL and Oracle
There have been jokes that have contributed to persistent myths about MongoDB's durability. The...
dev.to
September 9, 2025 at 7:22 AM
For nearly a decade, MongoDB provided reliable persistence with one of the most robust storage engines. Yet somehow, the oldest jokes keep persisting, too, so here are some facts:
dev.to/franckpachot...
dev.to/franckpachot...
MongoDB is popular, inspiring databases to mimic its features on top of RDBMS. Examining execution plans can provide insight into how things work—such as how to simulate multi-key indexes in a database engine designed for single-key indexes on normalized schemas
dev.to/aws-heroes/d...
dev.to/aws-heroes/d...
DocumentDB: Comparing Emulation Internals with MongoDB
MongoDB is the leading database for document data modeling, with its Atlas service available on AWS,...
dev.to
September 1, 2025 at 12:14 PM
MongoDB is popular, inspiring databases to mimic its features on top of RDBMS. Examining execution plans can provide insight into how things work—such as how to simulate multi-key indexes in a database engine designed for single-key indexes on normalized schemas
dev.to/aws-heroes/d...
dev.to/aws-heroes/d...
If you update a row/document with the same values, is it still an update, or should the database skip the write? SQL vs NoSQL.
dev.to/franckpachot...
dev.to/franckpachot...
Updates to the Same Value: MongoDB Optimization
In MongoDB, when you update a field to the same value it already holds, the database optimizes the...
dev.to
August 28, 2025 at 7:45 PM
If you update a row/document with the same values, is it still an update, or should the database skip the write? SQL vs NoSQL.
dev.to/franckpachot...
dev.to/franckpachot...
Embedding a One-to-Many relationship into JSONB to avoid joins, if over 2KB, hides the join, but does not prevent it. Here's how PostgreSQL TOAST works:
dev.to/franckpachot...
dev.to/franckpachot...
Embedding into JSONB still feels like a JOIN for large documents
Think PostgreSQL with JSONB can replace a document database? It’s a tempting idea: embed your related...
dev.to
August 25, 2025 at 1:09 PM
Embedding a One-to-Many relationship into JSONB to avoid joins, if over 2KB, hides the join, but does not prevent it. Here's how PostgreSQL TOAST works:
dev.to/franckpachot...
dev.to/franckpachot...
Reposted by Franck Pachot
SQL or NoSQL?
@franckpachot.bsky.social explains how to pick the right model for your app in this #IntelliJIDEAConf session 👉 youtu.be/CuA84bJEjDo
@franckpachot.bsky.social explains how to pick the right model for your app in this #IntelliJIDEAConf session 👉 youtu.be/CuA84bJEjDo
August 20, 2025 at 12:03 PM
SQL or NoSQL?
@franckpachot.bsky.social explains how to pick the right model for your app in this #IntelliJIDEAConf session 👉 youtu.be/CuA84bJEjDo
@franckpachot.bsky.social explains how to pick the right model for your app in this #IntelliJIDEAConf session 👉 youtu.be/CuA84bJEjDo
New blog post about comparing and sorting arrays in @MongoDB 👇🏼
It's a long story with a short conclusion to help remind it.
dev.to/franckpachot...
It's a long story with a short conclusion to help remind it.
dev.to/franckpachot...
MongoDB arrays: sort order and comparison
Arrays in MongoDB are ordered lists of values, and querying them can be confusing because a field...
dev.to
August 18, 2025 at 9:42 AM
New blog post about comparing and sorting arrays in @MongoDB 👇🏼
It's a long story with a short conclusion to help remind it.
dev.to/franckpachot...
It's a long story with a short conclusion to help remind it.
dev.to/franckpachot...