On Thu, Jan 20, 2022 at 10:31:15PM +, Lugosi, Jim wrote:
> We are struggling to figure out what is going on. We are migrating from
> PostgreSQL 9.6 to PostgreSQL 13 w/ PostGIS. Our 9.6 version was compiled
> from source and the new version (13) was installed using Yum. BTW, the new
> version is on a VM that has 16GB of memory, two cores, and 500 GB of disk.
> In addition, we are using MapServer as our mapping engine and OpenLayers as
> the client side interface. Once we switch over to the new version of
> PostgreSQL, the performance takes a big nose dive. We have being tweaking
> and tuning the database and it appears to be happy but the response times
> from mapfile requests are 3 -7 seconds. Previously, the response time was
> below a second.
>
> Another point is that we populated the new database from the old (9.6), using
> pg_dump. Could this be causing issues? Should we load the data from
> scratch? We use ogr2ogr (GDAL) to help assist with loading of spatial data.
> Anyway, not really sure what the problem is.
>
> Lastly, why am I seeing so many requests as to the PostGIS version. It
> appears that every map request sends the following query "SELECT
> PostGIS_Version();", which in turn takes up a connection.
This list is for postgres development and bug reports.
I suggest to post here, instead:
https://www.postgresql.org/list/pgsql-performance/
Here's a list of needed info:
https://wiki.postgresql.org/wiki/Slow_Query_Questions
It's important to include the slow query itself.
--
Justin
