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2 votes
Accepted

Can I use MongoDB for storing data locally instead of storing in RAM?

The Mongo_DB_plugin can be configured to listen to actions on chain from a locally hosted node. This can be resource intensive in processing large blocks, you don't have the option to listen through ...
Nat's user avatar
  • 3,425
2 votes

is that a good way to gather smart contract action data in backend with Demux.js?

Demux is intended for use when there is s lot of data that you want to save to the blockchain but not necessarily to RAM. RAM is an expensive resource and only needed if the dApp needs access to the ...
Ami Heines's user avatar
  • 1,686
2 votes
Accepted

Onboarding new eos users to a note taking dapp

This issue has always been a tricky one, I believe steemit stores all the data on the block(which is insane if you consider the EOS ram prices). It is especially annoying for the second point that you ...
junep89's user avatar
  • 208
2 votes

Can we use mongodb store state?

Well, it depends. But you've already got the right path to reduce RAM usage. The first thing is whether the user state you mention is intend to be stored on the blockchain or not, fully or partly? ...
twksos's user avatar
  • 174
1 vote

How user data stored on the eos blockchain is compliant with regulations?

First of all, user data does not necessarily equal personal data and as long as you do not store personal data or something that falls under the GDPR on a public Blockchain you are ok. It's simple, ...
cmadh's user avatar
  • 1,929
1 vote
Accepted

nested stuff inside index_table

Without knowing the exact game logic I can't really answer your question but the following should at least show you how to nest objects. struct [[eosio::table]] user_t { struct card_skin_t { ...
cmadh's user avatar
  • 1,929
1 vote

What is the way to create a map from 256 bit integers to values?

My answer is too long to fit in comment, so leave here. I came to know we are using different terms, but saying same things. eosio::multi_index is a table and you can add items (I called these 'rows')...
conr2d's user avatar
  • 2,320
1 vote
Accepted

Failed to migrate to postgres database: nerror: duplicate key value violates unique constraint \"pg_namespace_nspname_index\"

Other than the error of the duplicate key I would get a deadlock detected error, if I ever ran the demux after previously running it, or I would get current transaction is aborted, commands ignored ...
coder123's user avatar
  • 141
1 vote

Where and who is storing all the memo field data when its included in a transaction?

That's not a clear question, because a memo-field can be implemented in several different ways and if a developer wants to, he can also store it in RAM. Assuming that you mean the memo of a standard ...
cmadh's user avatar
  • 1,929
1 vote

What is mongodb_plugin used for?

chain_plugin is actually the core part that manages the blockchain data structure in nodeos. Most of time it is enabled automatically. mongo_db_plugin is an add-on plugin that aims to replace the ...
Tong Shen's user avatar
  • 475
1 vote
Accepted

mongodb sync is not fast enough

nodeos syncing is very CPU intensive but mongo_db_plugin is even much more CPU and IO intensive. I see you are using a cloud server for nodeos, which is very likely not performant enough. In my ...
Tong Shen's user avatar
  • 475
1 vote

Onboarding new eos users to a note taking dapp

You may want to check out NoteChain, which is Block.one's note taking application that they use as an example project for dApp developers to use as boilerplate: NoteChain demonstrates the eosio ...
confused00's user avatar
  • 5,554
1 vote
Accepted

Using Demux to store data offchain in EOS blockchain

I've integrated it in my simple Chess Dapp if you'd like a code example: https://github.com/NatPDeveloper/eos-chess/tree/master/js/lib/demux-js Specifying contract:action to listen for: const ...
Nat's user avatar
  • 3,425
1 vote
Accepted

Can you upload binary files to RAM?

You definitely should not use RAM for binary data unless it's literally very few bytes. The RAM cost will be prohibitive. And just imagine it in scale: the current available amount of RAM can store ...
Gassa's user avatar
  • 598

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