How to search extra information which is attatched to a transaction?

Question

For example, in one smart contact, a transaction is made, which contains some extra information, let's say the buyer's name. Once the transaction is committed, it is saved into one block. As you know, there are thousand of transactions per second, and millions of blocks are generated by now.

Question, is there a quick way to look up one specific transaction by this buyer? the buyer's name is saved into the transaction before.

If I did not make it clear, let's make it simple, in smart contact "eosio.token", we can put a memo when doing a transfer. Is there an easy/quick way to search specific memo text on the blockchain?

It may be doable by enumerate all blocks and all transactions, but as you know, there are too many of them, and it keeps growing very fast, so it is probably not practical to enumerate all blocks. Do you have any other suggestions/idears ?

Any comments would be appreciated.

Answer 1

Is there an easy/quick way to search specific memo text on the blockchain?

No easy way to do this as far as I know. The basic way to do this is to download all blocks using nodeos, store them in a database using something like eosio::mongo_db_plugin, and then filtering them by memo (which will still potentially be very slow.)

Otherwise, you'd have to use a block explorer that indexes by memo or lets you search by memo, which, to my knowledge, doesn't exist yet.