> The problem with that is that SQL as a standard is so patchy and inconsistently implemented that effectively everything has database-specific features.
Noting that when it comes to such patchiness, sqlite's developers specifically prefer to follow PG's example. When they write new SQL features, their basis for comparison is literally always "do we get the same answer as PG?" Yes, there are differences between the two, but porting between sqlite and PG, provided no fancy PG features are involved, is very likely simpler than porting between any two other arbitrary SQL engines. (That's ignoring any performance factors - i'm only talking about semantic compatibility.)
Noting that when it comes to such patchiness, sqlite's developers specifically prefer to follow PG's example. When they write new SQL features, their basis for comparison is literally always "do we get the same answer as PG?" Yes, there are differences between the two, but porting between sqlite and PG, provided no fancy PG features are involved, is very likely simpler than porting between any two other arbitrary SQL engines. (That's ignoring any performance factors - i'm only talking about semantic compatibility.)