I'm confused about the single-user mode (working with latest Dec2016 from hg).

'mserver5 --single-user' can also be set with 'monetdb set singleuser=yes'. 

However, 'monetdb get all' doesn't show 'singleuser' as one of the options, I had to guess it myself.

It would be nice if monetdb could show an actual list of available options, instead a manually compiled one.

is 'mserver5 --single-user' expected to put the database in a locked state, equivalent to 'monetdb lock' ?

If the answer is yes, then it doesn't do it consistently:

- it does allow to use COPY INTO.... LOCKED (from which you would think the database is locked)

but:

- it doesn't show the status of the database as locked

- it indeed allows new client connections

Could you clarify how 'single-user' and 'locked' relate?

Question 3 (long-ish)

I am pushing, via JDBC, the entire English DBpedia via COPY INTO (without 'LOCKED'), into a dbfarm on local SSD. 

It is about 200GB raw data and it takes ~9 hours.

Data goes through a pipeline of light pre-processing (feeding thread) and then inserted into the stream of COPY INTO (output thread). 

What I observe is that, at the beginning, the feeding thread is mush active, and the output thread very little.

After a couple of hours, the output thread is mostly active, and the feeding thread mostly idle.

I told myself that MonetDB is taking more and more time to flush appends to disk.

That's where I though using 'COPY INTO .. LOCKED' would help.

Not only it didn't help, but it got the symptoms worse. The output thread is almost 100% active, and the feeding thread almost 100% idle.

Indeed, it is already running for 12h and still going on.

Was I wrong to expect that 'LOCKED' would help?

Thanks,

Roberto