Proposal: introducing table functions that export fuse table meta

[dantengsky]

Summary

introducing system table functions, which export fuse table's segment/block metadata

The "semantics" of this function:

• grab a snapshot of the given table db_name.tbl_name (by using catalog)
• list all the segment infors of the given table

about the schema of resultset, use DataType::Struct for nested data structure and Struct::List for map.
EDIT: let's start what flatten table first

later

• we may use the above function(s) to verify the effect of compaction/GC
• or even, as the upstream datasource of the distributed GC pipeline

---

• table function that shows fuse table history and basic statistics #3301

[Veeupup]

maybe with HTTP api to return json result with segments statistics will be more clear ? Because fuse meta data will have some complicated nested structure which can be described by nested json. @dantengsky

[dantengsky]

addressed by PR #3301