Dear pgsql hackers,
I am developing custom storage for pgsql tables. I am using md* functions and smgrsw[] structure to switch between different magnetic disk access methods.
I want to add some custom options while table created
psql# create table t(...) with (my_option='value');
And thus I want to set "reln->smgr_which" conditionally during smgropen(). If myoption='value' i would use another smgr_which
I am really stuck at this point.
smgr.c:
SMgrRelation
smgropen(RelFileNode rnode, BackendId backend){
...
if ( HasOption(rnode, "my_option","value")){ //<< how to implement this check ?
reln->smgr_which = 1; //new access method
}else{
reln->smgr_which = 0; //old access method
}
...
}
The question is --- can I read table options while the table is identified by "RelFileNode rnode" ??
The only available information is
typedef struct RelFileNode
{
Oid spcNode; /* tablespace */
Oid dbNode; /* database */
Oid relNode; /* relation */
} RelFileNode;
But there are no table options available directly from this structure.
What is the best way to implement HasOption(rnode, "my_option","value")
Thank you in advance for any ideas.
Sincerely,
Dmitry R
