Disable Lazy Loading with C# SQLite DataReader

I am using System.Data.SQLite and SQLiteDataReader in my C# project. I am facing performance issues when getting the results of a query with attached databases.

Here is an example of a query to search text into two databases :

ATTACH "db2.db" as db2;

SELECT DISTINCT MainRecord.RecordID,
((LENGTH(MainRecord.Value) - LENGTH(REPLACE(UPPER(MainRecord.Value), UPPER("FirstValueToSearch"), ""))) / 18) AS "FirstResultNumber",
((LENGTH(DB2Record.Value) - LENGTH(REPLACE(UPPER(DB2Record.Value), UPPER("SecondValueToSearch"), ""))) / 19) AS "SecondResultNumber"
FROM main.Record MainRecord
JOIN db2.Record DB2Record ON DB2Record.RecordID BETWEEN (MainRecord.PositionMin) AND (MainRecord.PositionMax)
WHERE FirstResultNumber > 0 AND SecondResultNumber > 0;

DETACH db2;

When executing this query with SQLiteStudio or SQLiteAdmin, this works fine, I am getting the results in a few seconds (the Record table can contain hundreds of thousands of records, the query returns 36000 records).

When executing this query in my C# project, the execution takes a few seconds too, but it takes hours to run through all the results.

Here is my code :

// Attach databases

SQLiteDataReader data = null;

using (SQLiteCommand command = this.m_connection.CreateCommand())
{
    command.CommandText = "SELECT...";
    data = command.ExecuteReader();
}

if (data.HasRows)
{
    while (data.Read())
    {
        // Do nothing, just iterate all results
    }
}

data.Close();

// Detach databases

Calling the Read method of the SQLiteDataReader once can take more than 10 seconds ! I guess this is because the SQLiteDataReader is lazy loaded, am I right ? Is there a way to disable lazy loading ?

Thank you.