Re: Queries are taking way longer in 9.6 than 9.5

On 17/01/17 23:21, Tomas Vondra wrote:
> Hi,
>
> after looking at the explain plans again, I very much doubt those come from the same query. The reason is the 9.5 plan contains this part:
>
> -> HashAggregate (cost=67.54..68.12 rows=192 width=4)
> Group Key: d.vip_patient_id
> -> Nested Loop (cost=0.17..67.44 rows=192 width=4)
> -> Index Scan using unq_user_name on tblcnaccounts ...
> Index Cond: ((user_name)::text = 'dddddd'::text)
> -> Index Only Scan using idx_tblcndoctorpatientmap ...
> Index Cond: (master_user_id = a.master_user_id)
>
> while the 9.6 plan does not include anything like that, i.e. there's only a single aggregate at the top level, without any group keys. Also, the SQL query you've provided does not include any GROUP BY clause, so I claim that those plans are from two different queries.

There's also a user_name = 'dddddd' that has become a user_name = 'rdoyleda' ...

Ravi, could you please send the current query you're testing and the explain analyze of that query on 9.5 and 9.6?

Bye,
Chris.