DataReader->Read speed very slow #1235

Activity

1. cincuranet commented on Sep 17, 2025

   

   cincuranet

   on Sep 17, 2025

   Member

   More actions

   It's hard to provide any guidance without seeing the actual code...
2. Zeki-Gursoy commented on Sep 17, 2025

   

   Zeki-Gursoy

   on Sep 17, 2025

   Author

   More actions

   It's hard to provide any guidance without seeing the actual code...

   OK, please use...

   DDL:

   create database 'c:\users\zg\desktop\testdb.fdb'
     user 'SYSDBA'
     password '1'
     page_size = 8192
     default character set none
     collation none;
   
   create table "testtable" (
     "testfield" integer);
   
   execute block
   as
   declare i int = 1;
   begin
   	while(i <= 10000000) do
   	begin
   		insert into "testtable"("testfield") values(:i);
   		i = i + 1;
   	end
   end

   C#

   private void button1_Click(object sender, EventArgs e)
   {
       var csb = new FbConnectionStringBuilder()
       {
           Database = @"c:\users\zeki\desktop\testdb.fdb",
           DataSource = "localhost",
           UserID = "SYSDBA",
           Password = "1"
       };
   
       var cn = new FbConnection(csb.ConnectionString);
       var cmd = new FbCommand(@"select ""testfield"" from ""testtable"" ", cn);
       cn.Open();
   
       var rdr = cmd.ExecuteReader();
   
       var sw = new Stopwatch();
       sw.Start();
   
       while (rdr.Read())
       {
           _ = rdr.GetInt32(0);
       }
   
       sw.Stop();
   
       rdr.Close();
       cmd.Dispose();
       cn.Close();
   
       MessageBox.Show(sw.Elapsed.Seconds.ToString());
   }
3. BFuerchau commented on May 1, 2026

   

   BFuerchau

   on May 1, 2026

   More actions

   You can get result a little bit faster if you set FetchSize (Command or Connectionstring) to the max 32767. The Default is 200 only.
   This reduce server roundtrip.

   In the past i have made a proposal code to speed up roundabout 30%, because the client use a heavy workload with memory allocation and garbage collection, but this is ignored:-(.