We are trying to start using docker in our development team and I’m trying out the database in docker, but the performance is really poor. I find this very strange because I’ve tried to find a possible cause, but I can’t find any.
In my tests I have one cartesian product and distinct query should have a response time in 2ms but have 50ms response time in docker.
Maby I’m just missing something obvious, but I have tried many different combinations and checked lots of forums.
Any Ideas? It’s been a long week. 
Test:
Query with moderate data amount and complexity. Cartesian Product and distinct. Total multiplied 10M Rows. Should have response time 2ms. The end resultset is a couple of hundred rows and few MB of data.
Strange:
When I test my query in both environments there is a diff in responsetime, but the same “explained query time” (the query broken down in pieces and ms by oracle query engine).
I find no increase in CPU, Disk or Memory load, even if I repeat the query. There are only block reads (cache hits) and no disk reads.
Tried:
- Remove Docker NAT.
- Use the “-net=host” flag.
- Use “correct” swap. (Oracle accepts is)
Monitor tools:
- Disk performance (IOTop + Docker stats)
- Net performance (IFTop + Docker stats)
- CPU (Top + Docker stats)
- SQL Query performance (SqlPlus - set timing on - set autotrace on )
Enviornment:
- MAC book pro 16GB ram iCore7 SSD.
- VMware Fusion 6.0.4
Docker containers tested:
- alexeiled/docker-oracle-xe-11g (DockerHub)
- wnameless/oracle-xe-11g (DockerHub)
- madhead/docker-oracle-xe (GitHub)
- Own container build from CentOS7 and latest Oracle XE.
Docker env:
- Latest Boot2Docker
- Own Debian 7 installation.