[de6u99er]

The trick of becoming really good at SQL (applies to all areas of IT) is having a certain ambition to produce high performance beautiful (readable) code.

This requires experience which can only be gained by rolling up your sleves and working on stuff until the high ambition has been satisfied. Sometimes when I see old code from myself, and I can follow what I have been doing I get really proud of myself. Many times I end up slightly improving it based on new knowledge I have acquired since I initially wrote it.

[AdrianB1]

Readable code can be easily done via good formatting, but performance requires a combination of writing the query in the right way and the indexes to support it. The second part is not even visible from the query and most of the time is not self-explanatory, but the best part is that indexing is not even universally valid, statistics decide execution plans and the same query with the same indexes can result in very different performance on 2 different instances.

[minism]

High performance and readable certainly. Not sure why beautiful would be something to strive for though

[ducharmdev]

I believe they're intending to say that beautiful code == readable code.