On 14.3.2014 23:06, Peter Geoghegan wrote: > For the benefit of anyone that would like to try the patch out, I make > available a custom format dump of some delicious sample data. I can > query the sample data as follows on my local installation: > > [local]/jsondata=# select count(*) from delicious ; > count > --------- > 1079399 > (1 row) > > [local]/jsondata=# \dt+ delicious > List of relations > Schema | Name | Type | Owner | Size | Description > --------+-----------+-------+-------+---------+------------- > public | delicious | table | pg | 1174 MB | > (1 row) > > It's available from: > http://postgres-benchmarks.s3-website-us-east-1.amazonaws.com/jsondata.dump
Thanks. I've been doing some simple queries on this dataset and ISTM there's a memory leak somewhere in the json code (i.e. something is probably using a wrong memory context), because this query: SELECT doc->'title_detail'->'value', COUNT(*) FROM delicious GROUP BY 1; results in this: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 8231 tomas 20 0 5987520 4,645g 6136 R 95,4 60,4 0:37.54 postgres: tomas delicious [local] I have shared_buffers=1GB and work_mem=64MB, so 4.6GB seems a bit too much 4.6GB. Actually it grows even further, and then OOM jumps in and kills the backend like this: [ 9227.318998] Out of memory: Kill process 8159 (postgres) score 595 or sacrifice child [ 9227.319000] Killed process 8159 (postgres) total-vm:5920272kB, anon-rss:4791568kB, file-rss:6192kB I'm on commit a3115f0d, which is just 2 days old, so I suppose this was not fixed yet. regards Tomas -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers