When comparing Postgres vs SQL Server Express, the Slant community recommends Postgres for most people. In the question“What are the best ACID-compliant scalable databases?” Postgres is ranked 1st while SQL Server Express is ranked 7th. The most important reason people chose Postgres is:
Built by passionate developers, available for free, and is well supported by its active community.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open Source
Built by passionate developers, available for free, and is well supported by its active community.
Pro Supports migration from other major proprietary and open source databases
With the extensive SQL support and migration tools, Postgres users are easily able to migrate their databases over to the Postgres database with little effort.
Pro JSON support
JSON support allows for Postgres to transfer data as raw text and without attributes and markup overhead. This will result in new levels of speed, efficiency and flexibility for developers.
Pro Highly scalable
Continues to work well under low or heavy loads in order to meet the users' need.
Pro Object-Oriented Database
You can reuse existing approved design table and extend its capability by inheritance. You can reuse ancestor method byy declaring new trigger for descendant but reuse ancestor trigger procedure. You can add, remove or override column constraint making it differ from its ancestor. Applying OOP with database design help me reuse, extend, and encapsulate business logic and end up a rapid design, and less errants. PostgreSQL is a powerful RDBMS while its OOP is sufficient for OOP modular design. Especially its Open Source ,and free.
Pro True ACID-compliance
Built in, so users won't have to worry about atomicity, consistency, isolation and the durability of the database.
Pro Multi-Version Concurrency Control (MVCC)
Postgres uses MVCC. For each user connected to the database the Postgres database shows a snapshot of the database at a particular instance. When the database needs to update an item it will add the newer version and mark the old version as obsolete. This allows the database to save overhead but requires a regulated sweep to delete the old, obsolete data.
Pro Multiple Language Interfaces
"There are interfaces for Java (JDBC), ODBC, Perl, Python, Ruby, C, C++, PHP, Lisp, Scheme, and Qt just to name a few."
Pro Great query planner
Unlike MySQL, you generally don't spend time on hinting the query planner in order to make PostGres perform well.
Pro RETURNING option on INSERT queries
For example:
INSERT INTO table (field_1, field_2, field_3) VALUES (value_1, value_2, value_3) RETURNING id;
Pro Rich developer tools
SQL Server Express has deep integration with Visual Studio, Visual Web Developer and SQL Server Management allowing for ease-of-use and rich table and query designers. It may be the best choice for someone who develops in the Microsoft environment.
Pro Easily manage SQL Server instances
"Manage SQL Server Express databases with SQL Server Management Studio Express. Connect to local SQL Server Express databases and manage objects with full Object Explorer integration. Write, execute, and test queries by using visual query plans, and access management and maintenance options."
Pro Free
With a variety of versions to choose from the SQL Server Express version is free of charge. It is capable of upgrading to higher tiers, but that requires a fee.
Pro Easy backup and restore
Can be deployed to all editions of SQL Server and Microsoft Azure SQL Database
Cons
Con Overkill for simple setups
If a database will be doing many simple operations Postgres may be over-kill.
Con Vaccuuming can cause headaches
Con Can't be run as an embedded database
Con Proprietary
Con Hardware limitations
Maximum number of cores: 4
Maximum memory utilized per instance: 1GB
Maximum size: 10GB
This hardware could be limiting with some high profile apps and sites.