Re: CPU-intensive autovacuuming

Following up on my own post from last night:

> Could it be that there is some code in autovacuum that is O(n^2) in
> the number of tables?

Browsing the code using webcvs, I have found this:

for (j = 0; j < PQntuples(res); j++)
{
tbl_elem = DLGetHead(dbs->table_list);
while (tbl_elem != NULL)
{

I haven't really tried to understand what is going on in here, but it
does look like it is getting the result of the "pg_class join stats"
query and then matching it up against its internal list of tables using
nested loops, which is undoubtedly O(n^2) in the number of tables.

Have I correctly understood what is going on here?

--Phil.