On Wed, Apr 21, 2021 at 8:31 PM Fujii Masao <masao.fu...@oss.nttdata.com> wrote: > Applied. Attached is the updated version of the patch > (truncate_foreign_table_dont_pass_only_clause_v2.patch). > This patch includes the patch that Horiguchi-san posted upthead. > I'm thinking to commit this patch at first.
+1. > > 2) Instead of > > on foreign tables. <literal>rels</literal> is the list of > > <structname>Relation</structname> data structure that indicates > > a foreign table to truncate. > > > > I think it is better with: > > on foreign tables. <literal>rels</literal> is the list of > > <structname>Relation</structname> data structures, where each > > entry indicates a foreign table to truncate. > > Justin posted the patch that improves the documents including > this description. I think that we should revisit that patch. > Attached is the updated version of that patch. > (truncate_foreign_table_docs_v1.patch) One comment on truncate_foreign_table_docs_v1.patch: 1) I think it is "to be truncated" + <literal>rels</literal> is a list of <structname>Relation</structname> + data structures for each foreign table to truncated. How about a slightly changed phrasing like below? + <literal>rels</literal> is a list of <structname>Relation</structname> + data structures of foreign tables to truncate. Other than above, the patch LGTM. > > 3) How about adding an extra para(after below para in > > postgres_fdw.sgml) on WHY we don't push "ONLY" to foreign tables while > > truncating? We could add to the same para for other options if at all > > we don't choose to push them. > > <command>DELETE</command>, or <command>TRUNCATE</command>. > > (Of course, the remote user you have specified in your user mapping must > > have privileges to do these things.) > > I agree to document the behavior that ONLY option is always ignored > for foreign tables. But I'm not sure if we can document WHY. > Because I could not find the past discussion about why ONLY option is > ignored on SELECT, etc... Maybe it's enough to document the behavior? +1 to specify in the documentation about ONLY option is always ignored. But can we specify the WHY part within deparseTruncateSql, it will be there for developer reference? I feel it's better if this change goes with truncate_foreign_table_dont_pass_only_clause_v2.patch > > 4) Isn't it better to mention the "ONLY" option is not pushed to remote > > -- truncate with ONLY clause > > TRUNCATE ONLY tru_ftable_parent; > > > > TRUNCATE ONLY tru_ftable; -- truncate both parent and child > > SELECT count(*) FROM tru_ftable; -- 0 > > > > 5) I may be missing something here, why is even after ONLY is ignored > > in the below truncate command, the sum is 126? Shouldn't it truncate > > both tru_ftable_parent and > > -- truncate with ONLY clause > > TRUNCATE ONLY tru_ftable_parent; > > SELECT sum(id) FROM tru_ftable_parent; -- 126 > > Because TRUNCATE ONLY command doesn't truncate tru_ftable_child talbe > that inehrits tru_ftable_parent. No? I get it. tru_ftable_child is a local child so ONLY doesn't truncate it. With Regards, Bharath Rupireddy. EnterpriseDB: http://www.enterprisedb.com
