Hive 29279: Make table ddl task work with catalog #6252
Conversation
| } | ||
| -> ^(TOK_TABNAME $cat $db $tab $meta?) | ||
|
|
||
| // case 2：db.table |
There was a problem hiding this comment.
@zhangbutao , For iceberg meta tables like snapshots, files etc. the select * from db.tbl.meta should work which is the existing behaviour. Meaning, case 2 should have meta? IMO. Won't it misinterpret this example select with the case 1?
There was a problem hiding this comment.
Yes. There will be a breaking change here. We cannot distinguish between the semantic expressions cat.db.tbl and db.tbl.meta, so for Iceberg's meta tables, I will switch to using the format cat.db.tbl.meta, or reference Trino's approach as shown at https://trino.io/docs/current/connector/iceberg.html#metadata-tables, for example: SELECT * FROM "test_table$properties". In any case, this will cause backward compatibility issues.
Regarding this breaking change, I will initiate a discussion in the dev community mailing list to see if anyone has better suggestions.
zhangbutao
force-pushed
the
HIVE-29279_cat_tbl
branch
from
bd4a562 to
2fa7ee4
Compare
|
3 participants
What changes were proposed in this pull request?
The purpose of this PR is to implement table-related DDL statements such as create/show/drop/alter to correctly recognize the semantics of cat.db.tbl, thereby implementing DDL operations on tables in non-default catalogs.
There are many table DDL interfaces that need to be refactored. This PR is temporarily marked as a draft, but if anyone is interested, suggestions are always welcome.
Why are the changes needed?
Does this PR introduce any user-facing change?
How was this patch tested?