> Yeah, this is a bug: it's effectively double-counting the
> selectivity of the index clause. The error isn't enormously critical,
> since the join size estimate is right; but it could perhaps lead to
> choosing a plain indexscan when a bitmap scan would be better. I've
> applied a patch.
Thank you. I'll try that.
I was able to change the PgBackendStatus struct to hold a "percentage of completion" field, which shows up when calling
thepg_stat_get_activity function.
As I said in a previous mail, the progress indicator gives very good estimates for the simple queries I need. If I can
comeup with something that is good in general I'll post it. I'm reading some papers about the argument (mostly the ones
listedin http://wiki.postgresql.org/wiki/Query_progress_indication).