Subquery cache roadmap

[sopel39]

https://github.com/trinodb/trino/pull/21888 introduces subquery cache feature to Trino engine. However, there are many follow up items to improve the performance and hit rate.

Here are the roadmap items:

### Tasks
- [ ] https://github.com/trinodb/trino/issues/22116
- [ ] https://github.com/trinodb/trino/issues/22117
- [ ] https://github.com/trinodb/trino/issues/22118
- [ ] https://github.com/trinodb/trino/issues/22119
- [ ] https://github.com/trinodb/trino/issues/22120
- [ ] https://github.com/trinodb/trino/issues/22121
- [ ] https://github.com/trinodb/trino/issues/22122
- [ ] https://github.com/trinodb/trino/issues/22165
- [ ] https://github.com/trinodb/trino/issues/22167
- [ ] https://github.com/trinodb/trino/issues/22168

[chenjian2664]

@sopel39 I am interested in contributing to this topic, but I am not very familiar with the tasks mentioned above. Could you guide me on how to start and suggest which task or tasks might be suitable to start

[osscm]

Thanks a lot @sopel39 !

We had discussed a couple of times on the old issue about the implementation and approach.

As discussed we were also looking into the same problem, and would be more than happy to contribute. Please share your thoughts, where do you think I can work on.

May be,

https://github.com/trinodb/trino/issues/22116 Or https://github.com/trinodb/trino/issues/22165 Or

Whatsoever task you think.

Thanks.

[sopel39]

Hi @osscm

Take into consideration that it will probably take some time to land this PR. I'm extracting smaller PRs atm. However, I think we should also progress with the improvements.

https://github.com/trinodb/trino/issues/22116 and https://github.com/trinodb/trino/issues/22165 are both important. Especially https://github.com/trinodb/trino/issues/22116 will improve cache hit rate for string partition types, which are fairy common.

However, I would start with something simpler like https://github.com/trinodb/trino/issues/22120 to familiarize with the concepts (code can still change in the process of review)

I would start with something simpler like https://github.com/trinodb/trino/issues/22121 to familiarize with the concepts (code can still change in the process of review)

[sug-ghosh]

Hi @sopel39

I am interested to contribute to this issue. Going through the code and implementation in understanding the issue. Can you please guide me which sub-task I can take up and able to contribute.

[sopel39]

@sug-ghosh I think we would need to sync. Ping me on slack please

[hackeryang]

Relevant PR: https://github.com/trinodb/trino/pull/21888