Support flexible data exporting demand in copy to

[MichaelScofield]

What problem does the new feature solve?

copy to can only export data within a time range, which is not sufficient for various data exporting demand sometimes.

What does the feature do?

To meet the various data exporting demand, I think it's best for user to write queries in the copy to statement. Like this:

COPY tbl TO '/xxx/xxx/output.parquet' WITH (FORMAT = 'parquet', Q = 'select a, b from tbl where c = 1');

Only the data populated by the "Q" is exported. In this way, user could express his data exporting demand in the query, which is very flexible.

Implementation challenges

No response

[Kev1n8]

I'm interested in this. And I have a wonder regarding the implementation, looking forward to any suggestions:

Assume making time range option compatible with Q option. How should it behave when the cmd is: COPY tbl TO 'xxx.parquet' WITH (FORMAT = 'parquet', START_TIME = some_st, END_TIME = some_et, Q = 'SELECT * from tbl where ts <some_st')? One way I'm thinking is to perform AND on both time range filters inside and outside of the Q.

[MichaelScofield]

@Kev1n8 Thank you for being interested. I'm thinking we can use the "csv" of the alternative format in the http api instead. So I'm gonna close this issue. Thanks again!