PLV8ify

Introduction

plv8ify bundles typescript/javascript input and writes SQL file(s) containing Postgres functions using PLV8.

Why

• Interchange code between API and Database
• Write code in Typescript and use it in Postgres

Example

1. npm install -g plv8ify
2. Sample input.ts

const { point: turfPoint } = require('@turf/helpers')

export function point(lat, long) {
  const pt = turfPoint([lat, long])
  return pt
}

3. Run plv8ify generate
4. Step 3 emits SQL file with names like ./plv8-dist/plv8ify_point.plv8.sql (one for each exported function)
5. Execute the generated ./plv8-dist/plv8ify_point.plv8.sql using a Postgres client
6. Call the generated function using a Postgres client SELECT plv8ify_point(52.5200,13.4050);

See all examples in the examples folder. Use yarn examples to apply any changes to all the examples.

CLI Usage

Version

Print the version

Generate Command Flags	Type	Description	Default

Generate

Generate PLV8 functions for an input typescript file

Generate Command Flags	Type	Description	Default
--debug	Boolean	Print additional debug information	false
--bundler	'esbuild' or 'bun'	Pick bundler. Bun runtime is needed for 'bun'	esbuild
--write-bundler-output	Boolean	Write the intermediate bundled Javascript output from bundler (currently, only ESBuild interface exists)	false
--input-file	String	Specify an input file path (only Typescript supported at the moment)	input.ts
--output-folder	String	Specify an output folder	plv8ify-dist
--scope-prefix	String	Specify a scope prefix, by default plv8ify, adds plv8ify_ as prefix for exported typescript functions	plv8ify
--pg-function-delimiter	String	Specify a delimiter for the generated Postgres function	$plv8ify$
--fallback-type	String	Specify a fallback type when plv8ify fails to map a detected Typescript type to a Postges type	JSONB
--mode	'inline', 'bundle' or 'start_proc'	'inline' will bundle the library in each function, both 'bundle' and 'start_proc' creates a {prefix}_init function that loads the library. 'bundle' adds a check to each function to call 'init' if required, whereas 'start_proc' is designed to be used with plv8.start_proc	inline
--volatility	'IMMUTABLE' or 'STABLE' or 'VOLATILE'	Change the volatility of all the generated functions. To change volatility of a specific function use the comment format //@plv8ify-volatility-STABLE in the input typescript file (see examples/turf-js/input.ts). Note that for now only single-line comment syntax is supported.	IMMUTABLE

Deploy

Deploy an output folder to a Postgres database (defined by env var DATABASE_URL)

Generate Command Flags	Type	Description	Default
--output-folder	String	Specify an output folder	plv8ify-dist

Caveats

• Very early, only a small number of types supported
• Only supports typescript as input at the moment
• Scaling an application server is easier than scaling a database server, moving the logic in database as postgres functions makes it easier (IMO SQL is declarative, like React for data) to call the code/do some things but you are effectively shifting compute from application server to database server which might be a bad idea in most cases.

Prior Art

• https://github.com/CSTARS/es6-to-plv8
• https://github.com/clkao/plv8x

Contact

If you want to reach out to me, please DM me on https://twitter.com/divyenduz or email me at mail at divyendusingh.com