Just a side note - reading https://tanstack.com/db/latest/docs/guides/live-queries#reus... I see:

    const isHighValueCustomer = (row: { user: User; order: Order }) => 
     row.user.active && row.order.amount > 1000

    const isHighValueCustomer = (row: { user: User; order: Order }) => 
      and(row.user.active, gt(row.order.amount, 1000))

Yep, that's an error in the docs..