Alter table on demand is expensive

[fengjiachun]

What type of enhancement is this?

Performance

What does the enhancement do?

Every time we need to check if a new column needs to be added, we have to traverse all columns. While the schema usually remains unchanged, these checks are necessary. Maybe caching and hashing will be helpful to reduce the overhead of these checks.

https://github.com/GreptimeTeam/greptimedb/blob/0bb949787c12d26d14d8494605f336b5c3491648/src/operator/src/insert.rs#L377

Implementation challenges

No response