Hello,
I am trying to update a column using a PostGIS
ST_Buffer function into a table of 4.257.769 rows, but after 6 hours, an
Out of memory error appears and the kernel starts killing processes until a
Kernel Panic shows up.
I have simplified the buffer target geometry and also added a gist index to that column.
The statement is the following:
psql -h host -U user -W -d database -c "UPDATE table SET buffer = ST_Buffer(simplified_geometry, 0.005);"
After reading and tunning the configuration, I still have the same result.
Here's the initial memory stats:
total used free shared buff/cache available
Mem: 15G 1.5G 12G 503M 1.4G 13G
Swap: 7.8G 0B 7.8G
I'm running out of ideas, as I think the postgresql.conf memory parameters are quite low for the machine specs. I understand I can split the process and paginate the rows, but I can't see why I can't deal with this full statement right now.
Do you think this issue is related with the postgres memory parameters configuration? Why is not respecting the shared_buffers or effective_cache_size parameters and keeps growing?
Here's some info:
Machine specs
- Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz (8 cores)
- 16 GB of memory
- Fedora release 23 (Twenty Three)
- Kernel - 4.5.7-202.fc23.x86_64
postgresql.conf
- effective_cache_size = 5GB
- shared_buffers = 3GB
- work_mem = 10MB
- maintenance_work_mem = 800MB
- wal_buffers = 16MB
Kernel parameters
- kernel.shmmax = 8340893696
- kernel.shmall = 2036351
Versions:
- PostgreSQL 9.5.3 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 5.3.1 20160406 (Red Hat 5.3.1-6), 64-bit
- POSTGIS="2.2.2 r14797" GEOS="3.5.0-CAPI-1.9.0 r4084" PROJ="Rel. 4.9.1, 04 March 2015" GDAL="GDAL 2.0.2, released 2016/01/26" LIBXML="2.9.3" LIBJSON="0.12" RASTER