Question

this is my code

void fixInstellingenTabel(object source, ElapsedEventArgs e)
{
    NASDataContext _db = new NASDataContext();

    List<Instellingen> newOnes = new List<Instellingen>();

    List<InstellingGegeven> li = _db.InstellingGegevens.ToList();
    foreach (InstellingGegeven i in li) {
        if (_db.Instellingens.Count(q => q.INST_LOC_REF == i.INST_LOC_REF && q.INST_LOCNR == i.INST_LOCNR && q.INST_REF == i.INST_REF && q.INST_TYPE == i.INST_TYPE) <= 0) {
            // There is no item yet. Create one.
            Instellingen newInst = new Instellingen();
            newInst.INST_LOC_REF = i.INST_LOC_REF;
            newInst.INST_LOCNR = i.INST_LOCNR;
            newInst.INST_REF = i.INST_REF;
            newInst.INST_TYPE = i.INST_TYPE;
            newInst.Opt_KalStandaard = false;
            newOnes.Add(newInst);
        }
    }
    _db.Instellingens.InsertAllOnSubmit(newOnes);
    _db.SubmitChanges();
}

basically, the InstellingGegevens table gest filled in by some procedure from another server.
the thing i then need to do is check if there are new records in this table, and fill in the new ones in Instellingens.

this code runs for like 4 minutes on 15k records. how do I optimize it? or is the only way a Stored Procedure?

this code runs in a timer, running every 6h. IF a stored procedure is best, how to I use that in a timer?

        Timer Tim = new Timer(21600000); //6u
        Tim.Elapsed += new ElapsedEventHandler(fixInstellingenTabel);
        Tim.Start();

Answer 1

Doing this in a stored procedure would be a lot faster. We do something quite similar, only there is about 100k items in the table, it’s updated every five minutes, and has a lot more fields in it. Our job takes about two minutes to run, and then it does updates in several tables across three databases, so your job would reasonably take only a couple of seconds.

The query you need would just be something like:

create procedure UpdateInstellingens as

insert into Instellingens (
  INST_LOC_REF, INST_LOCNR, INST_REF, INST_TYPE, Opt_KalStandaard
)
select q.INST_LOC_REF, q.INST_LOCNR, q.INST_REF, q.INST_TYPE, cast(0 as bit)
from InstellingGeven q
left join Instellingens i
  on q.INST_LOC_REF = i.INST_LOC_REF and q.INST_LOCNR = i.INST_LOCNR
  and q.INST_REF = i.INST_REF and q.INST_TYPE = i.INST_TYPE
where i.INST_LOC_REF is null

You can run the procedure from a job in the SQL server, without involving any application at all, or you can use ADO.NET to execute the procedure from your timer.