Make update slightly more memory efficient

src/tasks/scrape-sections.ts

@@ -40,20 +40,14 @@ export class ScrapeSectionsTask {
 		}
 
 		await db.serializable(this.pool, async trx => {
-			// Mark courses and sections in term as deleted by default
+			// Mark courses in term as deleted by default
 			await db.update('Course', {
 				deletedAt: new Date(),
 			}, {
 				semester,
 				year
 			}).run(trx);
 
-			await db.update('Section', {
-				deletedAt: new Date(),
-			}, {
-				courseId: db.sql`${db.self} IN (SELECT ${'id'} FROM ${'Course'} WHERE ${'semester'} = ${db.param(semester)} AND ${'year'} = ${db.param(year)})`
-			}).run(trx);
-
 			// Upsert courses
 			await db.upsert('Course', extensionCourses.map(extensionCourse => {
 				const [minCredits, maxCredits] = this.getCreditsRangeFromCourse(extensionCourse);
@@ -74,6 +68,15 @@ export class ScrapeSectionsTask {
 					'maxCredits'
 				])
 			}).run(trx);
+		});
+
+		await db.serializable(this.pool, async trx => {
+			// Mark sections in term as deleted by default
+			await db.update('Section', {
+				deletedAt: new Date(),
+			}, {
+				courseId: db.sql`${db.self} IN (SELECT ${'id'} FROM ${'Course'} WHERE ${'semester'} = ${db.param(semester)} AND ${'year'} = ${db.param(year)})`
+			}).run(trx);
 
 			// Upsert sections
 			const sectionsUpsertInput: Array<InsertableForTable<'Section'>> = extensionCourses.flatMap(extensionCourse => extensionCourse.sections.map(extensionSection => {