Question: At my work, my co-workers are considering using hyperfile as a database server for a windev project. I don't even know that kind of database, it's from PCSOFT, the company that develops windev.

Since windev can also work with microsoft sql server, I'm looking for advice on that kind of database (performance, stability, etc) from people who already used it.

Regards!

Answer: 
It depends on the size of your project. Actually, Windev works well with HyperFileSQL. It has been designed for it ! By using another DBMS, you cut yourself some feature such as direct-reading/modifying/deleting in your tables.

Your performances will decrease significantly as soon as you have a nice amount of records in a table (> 100'000). Your database management will become a nightmare since you can't execute several SQL requests at the same time. In example, i'm using another tool developped by a french guy to manage my databases and execute some updates.

Despite of this, it's stable and provides an easy way to interact with Windev's fields.

In my opinion, Hyperfile SQL should be used with small applications with a small amount of features and datas.
If you want a free database, use PostgreSQL, the Windev connector for PostgreSQL is free to download and install on your windev as a replacement for HFSQL, it will be way more powerful while using the usual hFunctions like you would with HFSQL, plus you will find a ton of docs on the web to do powerful stuff.

HFSQL is in fact the same as an old ISAM DBASE database so it requires re-indexations and things like that of those older DB systems era.

PostgreSQL is like having a free Oracle DB with all the powerful features and reliability, we dropped HFSQL for this and performance has increased tenfold plus all the other benefits while keeping our code pretty much the same, every day feels like we discover freebies and gifts from ProsgreSQL since our migration :)

Free VS Free... You gotta go with power and sheer size of web documentation and poeple available to help .