Most databases have users and groups to handle access rights. PostgreSQL is different as there are only roles. The Application User Story A new app has to be developed. The choosen RDBMS is PostgreSQL. The application does need different roles: A user to create objects A user for the application with rights to add and change data A group for different users for reporting with read only rights Creating Users PostgreSQL does not have users, there are only roles. A user role needs to be able to login and a password. In addition the a superuser or a role with the right CREATEROLE has to be used ..read more

I just want to expain how I discovered PostgreSQL and what my history is in terms of working with data and databases. How I Started With Data When I learned COBOL I also learned to handle data structures, because that’s what this language is about: doing stuff with data. And a big thanks to Grace Hopper whom I really admire. I liked it a lot because it was so easy to do things with data. Discovering Databases Later on, I discovered databases and it made life handling data much easier. What I used at the time is long dead and forgotten. SQL wasn’t around - back then, there was only one seller ..read more

Using PostgreSQL On Android There is an app for Android users, which will give you a terminal: Termux. With it’s package management you can install your beloved PostgreSQL. That does also include having PostGIS. There might also be an old Termux app available in the Google Play Store. Do not install this version, it is outdated and will not be updated anymore! Installation Of F-Droid F-Droid is an alternative package app store for Android. To install it, you need to change your Android settings and to allow external installations. After the installation is done, you open the F-Droid and search ..read more

pgsql_tweaks is a bundle of functions and views for PostgreSQL The soucre code is available on GitLab, a mirror is hosted on GitHub. One could install the whole package, or just copy what is needed from the source code. The extension is also available on PGXN. General changes In this release the recommended PostgreSQL version has been changed to 15. The test file does not include times anymore. There have been no new or changed features, therefore this is only a minor release ..read more

There are tons of blogs about PostgreSQL available on the web, including this one. There are some good opportunities, where you can learn PostgreSQL as a developer or DBA, but a good starting point is always the original PostgreSQL Documentation. If you are not sure about something, for example the parameters of a function, or tools like psql, the documentation almost always has the answer. Available For Free There are some websites available, where you can learn PostgreSQL for free. There is a list available on postgresql.org. PostgreSQL Tutorial It’s perfect to either, walk through the lesso ..read more

History PostgreSQL supports two types of JSON implementations: JSON and JSONB. The first implementation of JSON has been released in PostgreSQL 9.2 in 2012. JSONB has been added two years later in PostgreSQL 9.4. There are still two JSON standards, that differ. One is RFC7159 by Douglas Crockford. The other one the ECMA 404. PostgreSQL is using the RFC7159. Compared to the ANSI SQL standard, which is often not really human readable, this standard is short and easy to understand, it has only 15 pages. In March 2017 the ISO published a new standard, ISO/IEC TR 19075-6:2017, that defines how to i ..read more

The amount of configuration parameters have grown a lot since when I started using PostgreSQL. With PostgeSQL 14, the current version at the time writing, there are currently 346 parameters, that can be configured. Most of the time it is unnecessary to touch most of them. On the other hand, the default configuration is anything but usable for nearly anything, except en embedded environment. Looking At Configuration Parameters This can easily be solved with SQL: SHOW ALL; That results in three column listing of all parameters with their current setting and a decent description, what the para ..read more

The current hype is to put PostgreSQL databases into Kubernetes. Obviously it is adding another layer on top of the stack. That is something, that one always should have in mind, especially, if it is planned, to have it running in production. It adds to the stack of your DBAs, that they no have to handle K8s YAML configuration files as implemented by an operator, too. Also the access to the database server differs. What a DBA has learned about how to do proper backups and, more important, test backups and restore backups, does not work as learned. Changing a configuration by just some Ansible ..read more

pgsql_tweaks is a bundle of functions and views for PostgreSQL The soucre code is available on GitLab, a mirror is hosted on GitHub. One could install the whole package, or just copy what is needed from the source code. The extension is also available on PGXN. General changes In this release some checks for not supported PostgreSQL versions have been removed. In addition there are now paths for the version and test files generated for the releases. This puts them out of the path of the files containing the functions and views. View pg_foreign_keys In a PostgreSQL related group a question about ..read more

sparql_fdw Released The sparql_fdw is a foreign data wrapper to connect to query web databases with the SPARQL protocol from inside PostgreSQL written in Python. I met the guy who originally developed this foreign data wrapper at the pgDay Paris 2019, where I gave a talk about foreing data wrapper. He gave me the link to it and I tried to bring it to work. So far there has only been the initial commit in the original repository. As Multicorn seems to be abandoned, the extension did not work anymore with PostgreSQL 14. But there is a Multicorn2 extension available, which is maintained be good p ..read more