import { BaseSchema } from '@adonisjs/lucid/schema'

/**
 * The discard sweep of a dropped signature (tool, group, poster) read the whole pending_releases table per
 * signature: the planner took a parallel seq scan over the poster test, four minutes on the HDD that starved the
 * lanes' claims (LOG.md (134)). The waiting rows by signature make it an index range. By the poster's md5: a
 * poster of 2.7 kB broke the first build (a btree key is at most a third of a page), which left an invalid index
 * behind that IF NOT EXISTS would have taken for the real one; the drop clears it.
 */
export default class extends BaseSchema {
  static disableTransactions = true

  async up() {
    this.schema.raw(`DROP INDEX CONCURRENTLY IF EXISTS pending_releases_signature_idx`)
    this.schema.raw(
      `CREATE INDEX CONCURRENTLY IF NOT EXISTS pending_releases_signature_idx ON pending_releases (group_id, tool, md5(poster)) WHERE status = 0`
    )
  }

  async down() {
    this.schema.raw(`DROP INDEX CONCURRENTLY IF EXISTS pending_releases_signature_idx`)
  }
}