Dear Database Vendors

I have one wish for each database. Some of them are big wishes, so I thought I’ll better send them early. Only six month until Christmas, you know ;)

Oracle

'' IS NULL? Are you serious? I know, it has always been that way, but does that mean it will stay so forever?

SQL Server

Could you please enable READ_COMMITTED_SNAPSHOT per default? Or, at least, make it a mandatory question during database creation? That could prevent so many locking problems.

PostgreSQL

Could you please implement index-only scans (aka “covering indexes”)? It’s a great performance feature, which I really miss in PostgreSQL.

UPDATE: This one became true with PostgreSQL 9.2.

MySQL

Could you please implement the hash join algorithm? So many applications suffer from poor join performance, just because MySQL doesn’t have hash joins.

UPDATE: This one became true with MySQL 8.0.18.

From today’s perspective, it looks like my PostgreSQL wish is the only one that might come true. But I’ll keep hoping for the others as well.