Radcon Entec wrote:
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You are, of course, correct. "select count(*) from only feedback"
returns 0. I have never used (or even seen) PostgreSQL rules before.
When I run the query "select * from feedback where charge = 23017", I
get 538 records. Adding the word "only" gives me zero records, as
expected, and querying the feedback_active table gets me my 538
records. But the feedback table only has the INSERT rules you quoted
above. I clicked on the feedback table's Rules leaf and selected "New
Rule", and saw that I can create SELECT, INSERT, UPDATE and DELETE
rules. But even though I don't have a SELECT rule explicitly defined,
PostgreSQL appears to be smart enough to retrieve data from the
correct actual table when I think I'm selecting from the feedback
table. Is that standard behavior?
Of course, my next step will be to read the documentation.
You won't find the cause of your surprise reading up on rules. Read up
on inheritance, instead. It can do a lot, but a typical simple use is
table-partitioning as appears to be the case in your situation.
You start with the main (parent) table, say "events" then create a bunch
of child tables that inherit events, say events_jan, events_feb,
events_mar...
You never put actual data in "events" but create a rule or trigger that
looks at the month information and puts January events in events_jan,
February in events_feb and so on.
Select * from events is more-or-less equivalent to:
select * from events_jan union
select * from events_feb union...
Inheritance goes far beyond the simple case shown above. There's a lot
of nifty stuff you can do and a number of things that can bite you. But,
as you say, that's where the documentation comes in.
Cheers,
Steve
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