Re: invalidating cached plans

Harald Fuchs wrote:
> In article <6028(dot)1110785150(at)sss(dot)pgh(dot)pa(dot)us>,
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>
> > One possible approach is to do the invalidation on a sufficiently coarse
> > grain that we don't care. For example, I would be inclined to make any
> > change in a table's schema invalidate all plans that use that table at
> > all; that would then subsume the constraint problem for instance. This
> > doesn't solve the inlined function problem however.
>
> How about using an even coarser grain? Whenever something in the
> database in question changes, blindly throw away all cached plans for
> this DB.

We could, but the creation of a single temp table would invalidate all
caches, and temp table creation might be pretty frequent.

One idea would be to record if the function uses non-temp tables, temp
tables, or both, and invalidate based on the type of table being
invalidated, rather than the table name itself. I can imagine this
hurting temp table caching, but at least functions using regular tables
would not be affected, and functions using temp tables would work
reliably.

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