On 07.05.24 18:43, Paul Jungwirth wrote:
On 5/7/24 08:23, David G. Johnston wrote:
On Tue, May 7, 2024 at 7:54 AM Bruce Momjian <br...@momjian.us
<mailto:br...@momjian.us>> wrote:
In the two marked lines, it says "if one side of the foreign key uses
PERIOD, the other side must too." However, looking at the example
queries, it seems like if the foreign side has PERIOD, the primary
side
must have WITHOUT OVERLAPS, not PERIOD.
Does this doc text need correcting?
The text is factually correct, though a bit hard to parse.
"the other side" refers to the part after "REFERENCES":
FOREIGN KEY ( column_name [, ... ] [, PERIOD column_name ] )
REFERENCES reftable [ ( refcolumn [, ... ] [, PERIOD column_name ] ) ]
***(shouldn't the second occurrence be [, PERIOD refcolum] ?)
The text is pointing out that since the refcolumn specification is
optional you may very well not see a second PERIOD keyword in the
clause. Instead it will be inferred from the PK.
Maybe:
Finally, if the foreign key has a PERIOD column_name specification the
corresponding refcolumn, if present, must also be marked PERIOD. If
the refcolumn clause is omitted, and thus the reftable's primary key
constraint chosen, the primary key must have its final column marked
WITHOUT OVERLAPS.
Yes, David is correct here on all points. I like his suggestion to
clarify the language here also. If you need a patch from me let me know,
but I assume it's something a committer can just make happen?
In principle yes, but it's also very helpful if someone produces an
actual patch file, with complete commit message, credits, mailing list
link, etc.
