consider bundling handler writes per block into single DB tx

[holic]

I am thinking about cases in which I query my ponder service for data (which includes a "last updated block") where I might end up with partial data for that block and unintentionally miss completed data for that block.

This could be solved by bundling all DB writes for a given block into a single DB tx.

The downside is that you may not be able to get the written handler data from another handler or previous event within the same block.

[0xOlias]

Interesting idea. When you say your data includes a "last updated block", does that mean you have a single entity record that is getting updated by multiple event handlers within the same block? (That's a scenario where I can see why you would want the transactional guarantee).

A workaround might be to add metadata to the GraphQL schema, similar to what the graph does. We could do something like:

type Query {
  _metadata: Metadata!
}

type Metadata {
  latestEventTimestamp: Int!
  networks: [NetworkMetadata!]!
}

type NetworkMetadata {
  name: String! # mainnet, optimism
  chainId: Int! # 1
  latestEventBlockNumber: BigInt! # this is what you could use as a "last updated block"
}

Then, you could use _metadata.networks[0].latestEventBlockNumber as your "last updated block". This might not solve your problem, though. Lmk what you think!