In the Bitcoin, SPV node can query that its transaction is included specific block to full node that provides merkle path which has super fast calculation.
In terms of full nodes, they have full-ledger and merkle tree that is consist of transaction tree. so they can find some transaction queried by SPV node(light node) but my question is that how they can efficiently find it?
They may dislike compute to find transaction if they have to sequence search because they are busy to find hash value of block to earn block reward.
Sorry for my English.