该
ROW_NUMBER()功能将对性能产生负面影响，并且您正在运行数千次。您已经在使用
OracleDataReader-它不会一次将所有四百万行都拉到您的计算机上，它基本上是一次流一次或几行。
这必须在几分钟或几小时内完成，而不是几天-我们有几个进程以类似的方式在Sybase和SQL Server之间移动数百万条记录，并且花费不到五分钟。
也许试一下：
OracleCommand cmd = new OracleCommand("SELECt ... FROM TableName", oracle_connection);int batchSize = 500; using (OracleDataReader reader = cmd.ExecuteReader()){ List<Record> l = new List<Record>(batchSize); string[] str = new string[7]; int currentRow = 0; while (reader.Read()) { for (int i = 0; i < 7; i++) { str[i] = reader[i].ToString(); } l.Add(new Record(str[0], str[1], str[2], str[3], str[4], str[5], str[6])); // Commit every time batchSize records have been read if (++currentRow == batchSize) { Commit(l); l.Clear(); currentRow = 0; } } // commit remaining records Commit(l);}以下是
Commit可能的样子：
public void Commit(IEnumerable<Record> records){ // TODO: Use ES's BULK features, I don't know the exact syntax client.IndexMany<Record>(records, "index", "type"); // client.Bulk(b => b.IndexMany(records))... something like this}
