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PRQL is a solution in search of a problem. Lacking such, the problem had to be fabricated.
by j-a-a-p 3y ago
PRQL is a solution in search of a problem. Lacking such, the problem had to be fabricated.
- naasking 3y agoSQL has many problems that PRQL ostensibly addresses. Query reuse, composability, abstraction and more.
- ako 3y agoQuery reuse, composability and abstraction are all sufficiently solved with views in my experience.
- naasking 3y agoThen your experience doesn't extend to dynamic queries composed of query fragments, which is almost universal to all e-commerce sites. Views are a degenerate, second-class form of query abstraction, as are common table expressions and the numerous other features added to SQL over the years to paper over the lack of proper first-class query abstractions. It's like saying a programming language doesn't need first-class functions because we have disjoint unions and we can perform defunctionalization by hand. Strictly true, but really missing the point.
- ttfkam 3y agoWhen viewed as a DSL for set theory, views, CTEs, set-returning functions, et al are indeed proper first-class query abstractions. When viewed through the lens of general purpose imperative or functional programming languages, it's easy to see how it can be seen as falling short. I'll admit much of the tooling and driver APIs leave a lot to be desired. Some tools do make good efforts though such as nested fragments in this driver. https://github.com/porsager/postgres#building-queries https://github.com/porsager/postgres#building-queries
- naasking 3y ago> When viewed as a DSL for set theory, views, CTEs, set-returning functions, et al are indeed proper first-class query abstractions. It's still lacking even then. You can't assign a set to variable for instance, and then use that variable in other definitions or queries.
- ttfkam 3y agoYou can in Postgres. It's not often a good idea since it would constitute an optimization fence and potentially buffer large values in memory, but you can absolutely do this in a function variable. record[] some_table_name[] jsonb containing an array of records And of course the most obvious shared set variable of all, supported by every popular RDBMS in existence: the temporary table. Something scoped to the current session, of essentially unlimited width and length, and accessible to other definitions and queries. We get it. You want something closer to a general purpose programming language. But don't confuse your preferences with actual missing features.
- naasking 3y agoTemp tables are another bandaid. Like views, they are another second-class abstraction intended to address the lack of generality of relations. As you hint, adding second-class features is intended to handle pain points while keeping optimization simple, but it's the wrong way to do it IMO. No fixed number of second class features can make up for the lack of relations as first-class values, so this is not just a matter of preference. I actually don't want a general purpose programming language as that's not suitable for data access, I just want a query language that doesn't impose artificial limitations on relations. Edit: although I will admit that programming language theory is a hobby, so that's why I understand the source of the pain every time I have to use SQL. LINQ almost gets this right, but is still a huge improvement on SQL.
- ttfkam 3y agoHow would LINQ make jsonpath queries or unroll arrays on the database with unnest?