Pretty weak, partly terrible advice.
- Storing images and blobs: granted, usually not a good idea
- Limit/offset will take you a veeeery long way until you have to think about stuff like deep paging. And however you try to tackle that, if the stuff you paginate needs ordering, it's simply a hard problem and not a mistake.
- UUID primary keys? Horrible advice that's only applicable at Google/Facebook scale (and even they often use 64bit integer keys for a lot of entities, see Graph API or Adwords). Will wreak havoc on insert and join performance and index size. 64 bit is more than you'll ever need even for the most serious application.
- Default values on NULL columns: Okay advice, but a pretty random issue
- Going away from normalization is optimization that's mostly premature and regarding the drawbacks should only be done with utmost care and to resolve specific performance problems, not as a general approach.
Overall, pretty mediocre advice.
- Storing images and blobs: granted, usually not a good idea
- Limit/offset will take you a veeeery long way until you have to think about stuff like deep paging. And however you try to tackle that, if the stuff you paginate needs ordering, it's simply a hard problem and not a mistake.
- UUID primary keys? Horrible advice that's only applicable at Google/Facebook scale (and even they often use 64bit integer keys for a lot of entities, see Graph API or Adwords). Will wreak havoc on insert and join performance and index size. 64 bit is more than you'll ever need even for the most serious application.
- Default values on NULL columns: Okay advice, but a pretty random issue
- Going away from normalization is optimization that's mostly premature and regarding the drawbacks should only be done with utmost care and to resolve specific performance problems, not as a general approach.
Overall, pretty mediocre advice.