* Recreating the schema bindings:

  $ make -C src/sql update-dbix

* Running the test server:

  $ DBIC_TRACE=1 ./script/hydra_server.pl

* Setting the maximum number of concurrent builds per system type:

  $ psql -d hydra <<< "insert into SystemTypes(system, maxConcurrent) values('i686-linux', 3);"

* Creating a user:

  $ hydra-create-user root --email-address 'e.dolstra@tudelft.nl' \
      --password-prompt

  (Replace "foobar" with the desired password.)

  To make the user an admin:

  $ hydra-create-user root --role admin

  To enable a non-admin user to create projects:

  $ hydra-create-user root --role create-projects

* Changing the priority of a scheduled build:

  update buildschedulinginfo set priority = 200 where id = <ID>;

* Changing the priority of all builds for a jobset:

  update buildschedulinginfo set priority = 20 where id in (select id from builds where finished = 0 and project = 'nixpkgs' and jobset = 'trunk');
  

* Steps to install:

  - Install the Hydra closure.

  - Set HYDRA_DATA to /somewhere.
  
  - Run hydra_init.pl

  - Start hydra_server

  - Visit http://localhost:3000/

  - Create a user (see above)

  - Create a project, jobset etc.

  - Start hydra_evaluator and hydra_queue_runner


* Job selection:
  
    php-sat:build [system = "i686-linux"]
    php-sat:build [same system]
    tarball [same patchelfSrc]
    --if system i686-linux --arg build {...}


* Restart all aborted builds in a given evaluation (e.g. 820909):

  > update builds set finished = 0 where id in (select id from builds where finished = 1 and buildstatus = 3 and exists (select 1 from jobsetevalmembers where eval = 820909 and build = id));


* Restart all builds in a given evaluation that had a build step time out:

  > update builds set finished = 0 where id in (select id from builds where finished = 1 and buildstatus != 0 and exists (select 1 from jobsetevalmembers where eval = 926992 and build = id) and exists (select 1 from buildsteps where build = id and status = 7));


* select * from (select project, jobset, job, system, max(timestamp) timestamp from builds where finished = 1 group by project, jobset, job, system) x join builds y on x.timestamp = y.timestamp and x.project = y.project and x.jobset = y.jobset and x.job = y.job and x.system = y.system;

  select * from (select project, jobset, job, system, max(timestamp) timestamp from builds where finished = 1 group by project, jobset, job, system) natural join builds;


* Delete all scheduled builds that are not already building:

  delete from builds where finished = 0 and not exists (select 1 from buildschedulinginfo s where s.id = builds.id and busy != 0);


* select x.project, x.jobset, x.job, x.system, x.id, x.timestamp, r.buildstatus, b.id, b.timestamp
  from (select project, jobset, job, system, max(id) as id from Builds where finished = 1 group by project, jobset, job, system) as a_
  natural join Builds x
  natural join BuildResultInfo r
  left join Builds b on b.id =
    (select max(id) from builds c
     natural join buildresultinfo r2
     where x.project = c.project and x.jobset = c.jobset and x.job = c.job and x.system = c.system
           and x.id > c.id and r.buildstatus != r2.buildstatus);

* Using PostgreSQL (version 9.2 or newer is required): 

  $ HYDRA_DBI="dbi:Pg:dbname=hydra;" hydra-server


* Find the builds with the highest number of build steps:

  select id, (select count(*) from buildsteps where build = x.id) as n from builds x order by n desc;


* Evaluating the NixOS Hydra jobs:

  $ ./hydra_eval_jobs ~/Dev/nixos-wc/release.nix --arg nixpkgs '{outPath = /home/eelco/Dev/nixpkgs-wc;}' --arg nixosSrc '{outPath = /home/eelco/Dev/nixos-wc; rev = 1234;}' --arg services '{outhPath = /home/eelco/services-wc;}' --argstr system i686-linux --argstr system x86_64-linux --arg officialRelease false


* Show all the failing jobs/systems in the nixpkgs:stdenv jobset that
  succeed in the nixpkgs:trunk jobset:

  select job, system from builds b natural join buildresultinfo where project = 'nixpkgs' and jobset = 'stdenv' and iscurrent = 1 and finished = 1 and buildstatus != 0 and exists (select 1 from builds natural join buildresultinfo where project = 'nixpkgs' and jobset = 'trunk' and job = b.job and system = b.system and iscurrent = 1 and finished = 1 and buildstatus = 0) order by job, system;


* Get all Nixpkgs jobs that have never built succesfully:

  select project, jobset, job from builds b1
    where project = 'nixpkgs' and jobset = 'trunk' and iscurrent = 1
    group by project, jobset, job
    having not exists
      (select 1 from builds b2 where b1.project = b2.project and b1.jobset = b2.jobset and b1.job = b2.job and finished = 1 and buildstatus = 0)
    order by project, jobset, job;