Chore/fix user query

[gweiying]

Problem

Optimising our current query to check if short link exists. Previous query was doing an unnecessary join on the users table, causing the query duration to spike.

Solution

Replaced query to only check in urls table instead of joining urls with user table.

Before & After Screenshots

BEFORE:

AFTER:

Tests

• Ran load tests on staging to check if query duration reduced.

E2E Manual tests

• If short link is already used, should not be able to create short link
• When creating new links via APIs, should be able to create shortened link without specifying short link
• When creating new links via APIs, if short link is already used, should not be able to create short link

[halfwhole]

lgtm!

[halfwhole]

nit: small optimisation but unnecessary

Suggested change

	return !longUrl
	return true

edit should be false OOPS

[timotheeg]

/nit/micro-optimization: since we only care for an exists, you could reduce the selection to just the shortUrl field. Otherwise the query seems to be sent like this atm (according to the traces):

SELECT shortUrl, longUrl, state, isFile, contactEmail, description, source, tagStrings, createdAt, updatedAt, userId FROM urls WHERE url . shortUrl = ?

Suggested change

	const url = await Url.findOne({
	where: { shortUrl },
	})
	const url = await Url.findOne({
	attributes: ['shortUrl'],
	where: { shortUrl },
	})