Re: [PERFORM] query slowdown after 9.0 -> 9.4 migration

2016-10-26 Thread Andreas Kretschmer
Tomas Vondra wrote: > On 10/26/2016 03:48 PM, Filip Rembiałkowski wrote: >> Hi. >> >> Query run time degraded after migration from Pg 9.0 + postgis 1.5 to Pg >> 9.4 + postgis 2.2. >> EXPLAIN shows heap scan cost increase. What can be the reason for >> 40-fold increase in page scans needed to run

Re: [PERFORM] query slowdown after 9.0 -> 9.4 migration

2016-10-26 Thread Tomas Vondra
On 10/26/2016 03:48 PM, Filip Rembiałkowski wrote: Hi. Query run time degraded after migration from Pg 9.0 + postgis 1.5 to Pg 9.4 + postgis 2.2. 1 ms versus 7 ms. Same query, same data, same schema, similar hardware. Data is small and fits in cache. EXPLAIN shows heap scan cost increase. Wha

[PERFORM] query slowdown after 9.0 -> 9.4 migration

2016-10-26 Thread Filip Rembiałkowski
Hi. Query run time degraded after migration from Pg 9.0 + postgis 1.5 to Pg 9.4 + postgis 2.2. 1 ms versus 7 ms. Same query, same data, same schema, similar hardware. Data is small and fits in cache. EXPLAIN shows heap scan cost increase. What can be the reason for 40-fold increase in page scan