How different is PostgreSQL to MySQL? [closed]

PostgreSQL has some nice features like generate_series, custom aggregate functions, arrays etc, which can ease your life greatly if you take some time to learn them.

On the other hand it lacks some features of MySQL like using and assigning session variables in queries, FORCE INDEX, etc., which is quite annoying if you are used to these features.

If you just use basic SQL, then you will hardly notice any difference.

How different is PostgreSQL to MySQL?

That depends if you're talking about SQL only (which is mostly the same) or the stored procedures (which are quite different).

is this a realistic task?

Absolutely. PostgreSQL has very good documentation and community. There are also lot of ppl, who have experience with MySQL and PostgreSQL.

"MySQL vs PostgreSQL wiki" — centers on "which is better", but gives you some idea of differences.

PostgreSQL compared to MySQL is as any other pair of DBMSs compared. What they have in common is non-functional, specifically the consequences of each being open source. In terms of features, use, and strengths they are no closer to each other than PostgreSQL is to Oracle or DB2 is to Sybase.

Now on to your real question: you are a SQL guy, albeit one who has not yet had experience with PostgreSQL. This is a completely realistic task for you, and a good one since you'll expand your understanding of the varieties of DBMSs and gain a perspective on MySQL that you can't get from working solely within its sphere.

As someone who was once in exactly the same position, my guess is that you'll quickly pick up PostgreSQL and might even hesitate to return to MySQL ;-).