Thread

Re: [HACKERS] Arrays broken on temp tables

Bruce Momjian <maillist@candle.pha.pa.us> — 1999-11-11T02:37:52Z

> The problem is that the rangetable code doesn't realize that the logical
> and physical names refer to the same table, so when the
> subscript-processing code generates a reference to
> <physicaltablename>.<attribute> the parser generates a second RTE for
> the physical table name, in addition to the already-existing RTE for the
> logical table name.  This causes the planner to generate a join, because
> it can see no difference between this situation and
> 	FROM tablename, tablename aliasname
> which *should* cause a join.  But the join causes each tuple to be
> processed multiple times, which is the wrong thing for this case.
> 
> There is more than one way we could attack this, but I think the
> cleanest answer will be to make it possible to extract a logical
> table name from a relcache entry.

Well, as I remember, the good news is that our code was fine, and the
original poster just missed the WHERE clause on the update.  So I guess
that gets us off the hook for a while.

However, now looking at the posting again:

	http://www.postgresql.org/mhonarc/pgsql-hackers/1999-11/msg00213.html

I am confused again.

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