Running parallel queries

return await ctx.drizzle.transaction(
        async (tx) => {
          const threadId = nanoid();
          const [board, user] = await Promise.all([
            fetchBoard(tx, input.board_id),
            fetchUser(tx, ctx.userId),
            tx.insert(forumThread).values({
              id: threadId,
              title: input.title,
              boardId: input.board_id,
              userId: ctx.userId,
            }),
            tx.insert(forumPost).values({
              id: nanoid(),
              content: input.content,
              threadId: threadId,
              userId: ctx.userId,
            }),
            tx
              .update(forumBoard)
              .set({ nThreads: sql`nThreads + 1` })
              .where(eq(forumBoard.id, input.board_id)),
          ]);

          if (user.isBanned) {
            throw serverError("UNAUTHORIZED", "You are banned");
          }
          if (!board) {
            throw serverError("UNAUTHORIZED", "Board does not exist");
          }
          return threadId;
        },
        {
          isolationLevel: "read uncommitted",
          accessMode: "read write",
        }
      );