Custom Query Languages: Why? How?
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The document discusses custom query languages (CQL), focusing on their definition, benefits, and design principles, such as clarity and efficiency. It emphasizes the importance of a CQL in modeling specific domains for effective data retrieval and analysis, as well as the need for flexibility and user feedback in design. Additionally, it covers implementation approaches using parser generators like ANTLR to expedite development while balancing control over parsing details.
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DIMENSIONS
query language](https://image.slidesharecdn.com/jotb2017-customquerylanguages-why-how-170605094747/85/Custom-Query-Languages-Why-How-10-320.jpg)
![grammar Query;
query: target results EOF;
target:
'search' name filter?;
results: ('return' name)+;
name: [a-z]+;ANTLR4
GRAMMAR](https://image.slidesharecdn.com/jotb2017-customquerylanguages-why-how-170605094747/85/Custom-Query-Languages-Why-How-34-320.jpg)
Custom Query Languages: Why? How?
- 1. Custom Query Languages: Why? How? @AnjanaVakil - J on the Beach 2017
- 2. HOLA! I’m @AnjanaVakil Software Engineer/DSL-builder, ÜberResearch with input from Tobias Johansson Technical Lead, Valo
- 3. DIMENSIONS uberresearch.com/dimensions Scientific research funding data for funders, researchers, and research organizations.
- 4. VALO valo.io Real-time and historical analytics on data streams. Plus beachy conferences.
- 5. WHAT is a Custom Query Language (CQL) ?
- 6. CUSTOM QUERY LANGUAGE (CQL) domain- specific
- 7. CUSTOM QUERY LANGUAGE (CQL) data retrieval & analysis
- 8. CUSTOM QUERY LANGUAGE (CQL) text-based interface
- 9. “a common text that acts as both executable software and a description that domain experts can read Martin Fowler, Domain Specific Languages
- 10. search grants for "malaria" where funder.acronym="NIH" return categories, years, researchers:[surname] aggregate funding sort by funding DIMENSIONS query language
- 11. VALO query language from /streams/sensors/air group by sampleTime window of 1 minute select sampleTime, sensor, avg(pollution)
- 12. WHY would you want your own CQL ?
- 13. MODELING
- 14. VALO modeling time from historical /streams/tenant/collection/name group by timestamp window of 3 seconds every 1 second select timestamp, count(), sum(value) order by timestamp
- 15. Display from Model DECOUPLING Model from Storage
- 19. “Trying to describe a domain using a DSL is useful even if the DSL is never implemented. It can be beneficial just as a platform for communication. Martin Fowler, Domain Specific Languages
- 20. HOW should you design a CQL ?
- 21. 1. Clarity 2. Concision 3. Familiarity 4. Responsiveness WHAT MAKES A GREAT USER INTERFACE? 5. Consistency 6. Aesthetics 7. Efficiency 8. Forgiveness https://www.smashingmagazine.com/user-interface-design-in-modern-web-applications
- 22. 1. 2. Concision 3. Familiarity 4. the user can easily express what they want 5. 6. Aesthetics 7. Efficiency 8.
- 23. VALO historical data from historical /streams/sensors/air group by sampleTime window of 1 minute select sampleTime, sensor, avg(pollution)
- 24. 1. Clarity 2. 3. Familiarity 4. Responsiveness the user doesn’t often need the docs 5. Consistency 6. 7. 8. Forgiveness not
- 25. Unknown source 'articles' Did you mean one of these sources? applications clinical_trials grants patents publications DIMENSIONS error messages
- 26. it will change but no matter how good your design
- 27. Get user feedback ASAP expect & embrace change (as usual) Design for flexibility
- 28. HOW can you implement a CQL ?
- 29. PARSING YOUR CQL Terrence Parr, The Definitive ANTLR4 Reference
- 30. Use a parser generator Prototype quickly, giving up control over some details of lexing/parsing. e.g. ANTLR, parboiled2 PARSING YOUR CQL Roll your own Retain full control over lexing/parsing and internal syntactic representation.
- 31. Use a parser generator Prototype quickly, giving up control over some details of lexing/parsing. e.g. ANTLR, parboiled2 PARSING YOUR CQL Roll your own Retain full control over lexing/parsing and internal syntactic representation.
- 32. ANTLR (v4) antlr.org Java-based parser generator with targets for various other languages (e.g. Python, JS, …)
- 33. THE ANTLR4 FLOW grammar lexer parser AST listener
- 34. grammar Query; query: target results EOF; target: 'search' name filter?; results: ('return' name)+; name: [a-z]+;ANTLR4 GRAMMAR
- 35. # Generated by ANTLR 4.5 from antlr4 import * class QueryListener: def enterTarget(self, ctx): pass def exitTarget(self, ctx): pass ANTLR4 LISTENER
- 36. Let’s RECAP !
- 37. CUSTOM QUERY LANGUAGES WHY bother An executable model of your domain/logic. Decoupling display, model, and storage. HOW to design Language as interface. Expect & embrace change. HOW to implement Parser generators can speed up prototyping, at the cost of some control.
- 38. GRACIAS!I’m @AnjanaVakil anjana@uberresearch.com Huge thanks to Tobias Johansson & Valo! Presentation template by SlidesCarnival