【发布时间】:2017-02-26 23:18:05
【问题描述】:
这是我当前的代码。打开接收任何 cmets 以提高内存优化。
当我使用 1000000*8 数据采集 1000000 * 8 样本时,它会导致内存不足异常。希望有关于优化内存使用的建议。
比较名为“Before”和“After”的数据集中的两个表,并填写所有结果表。
private bool CompareAndFillResultTable(DataSet ds)
{
Stopwatch stopWatch = new Stopwatch(); stopWatch.Start();
System.Data.DataTable dt_copy;
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["Before"].Copy();
dt_copy.TableName = "BeforeBackup";
ds.Tables.Add(dt_copy);
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["After"].Copy();
dt_copy.TableName = "AfterBackup";
ds.Tables.Add(dt_copy);
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["Before"].Clone();
dt_copy.TableName = "BeforeSingular";
ds.Tables.Add(dt_copy);
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["Before"].Clone();
dt_copy.TableName = "AfterSingular";
ds.Tables.Add(dt_copy);
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["Before"].Clone();
dt_copy.TableName = "Duplicates";
ds.Tables.Add(dt_copy);
dt_copy = new System.Data.DataTable();
dt_copy = ds.Tables["Before"].Clone();
dt_copy.TableName = "Mismatch";
ds.Tables.Add(dt_copy);
foreach (System.Data.DataTable table in ds.Tables)
{
table.Columns.Add("Source_Label");
}
//Remove identical from before, then after
for (int i = 0; i < ds.Tables["Before"].Rows.Count; i++)
{
string BeforeCompareKeyVal = ds.Tables["Before"].Rows[i][Inputs.SortColumn].ToString();
if (ds.Tables["After"].Rows.Count > 0)
{
for (int j = 0; j < ds.Tables["After"].Rows.Count; j++)
{
string AfterCompareKeyVal = ds.Tables["After"].Rows[j][Inputs.SortColumn].ToString();
if (ds.Tables["Before"].Rows[i].ItemArray.SequenceEqual(ds.Tables["After"].Rows[j].ItemArray))
{
//copy Aftter row to duplicate Table and Remove row from After
DataRow rw = ds.Tables["After"].Rows[j];
rw[ds.Tables["After"].Columns.Count - 1] = "NA";
ds.Tables["Duplicates"].ImportRow(rw);
ds.Tables["After"].Rows.RemoveAt(j);
j--;
break;
}
if (Int64.Parse(BeforeCompareKeyVal) > Int64.Parse(AfterCompareKeyVal))// Review - 7
{
if (true)//all dup after + a before - set logic
{
//Copy After row to AfterSingular Table and Remove row from After
DataRow rw = ds.Tables["After"].Rows[j];
rw[ds.Tables["After"].Columns.Count - 1] = "After";
ds.Tables["AfterSingular"].ImportRow(rw);
ds.Tables["After"].Rows.RemoveAt(j);
j--;
if (ds.Tables["After"].Rows.Count == 0)
{
rw = ds.Tables["Before"].Rows[i];
rw[ds.Tables["Before"].Columns.Count - 1] = "Before";
ds.Tables["BeforeSingular"].ImportRow(rw);
}
continue;
}
}
if (Int64.Parse(BeforeCompareKeyVal) < Int64.Parse(AfterCompareKeyVal))// Review - 7
{
if (true)//all dup after and a before set logic
{
//Copy Before row to BeforeSingular Table
DataRow rw = ds.Tables["Before"].Rows[i];
rw[ds.Tables["Before"].Columns.Count - 1] = "Before";
ds.Tables["BeforeSingular"].ImportRow(rw);
break;
}
}
if (Int64.Parse(BeforeCompareKeyVal) == Int64.Parse(AfterCompareKeyVal))// Review - 7
{
//Copy Before, After row to Mismatch Table and Remove row from After
if (true)//all dup after and a before set logic
{
DataRow rwB = ds.Tables["Before"].Rows[i];
rwB[ds.Tables["Before"].Columns.Count - 1] = "Before";
DataRow rwA = ds.Tables["After"].Rows[j];
rwA[ds.Tables["After"].Columns.Count - 1] = "After";
ds.Tables["Mismatch"].ImportRow(rwB);
ds.Tables["Mismatch"].ImportRow(rwA);
ds.Tables["After"].Rows.RemoveAt(j);
j--;
break;
}
}
}
}
else
{
DataRow rw = ds.Tables["Before"].Rows[i];
rw[ds.Tables["Before"].Columns.Count - 1] = "Before";
ds.Tables["BeforeSingular"].ImportRow(rw);
continue;
}
}
//Add remaining after table rows to AfterSingular table
ds.Tables["AfterSingular"].Merge(ds.Tables["After"]);
//ds.Tables["AfterSingular"].Columns.Add("Source_Label", System.Type.GetType("System.String"), "After_Singular");
//ds.Tables["BeforeSingular"].Columns.Add("Source_Label", System.Type.GetType("System.String"), "Before_Singular");
//foreach (System.Data.DataTable table in ds.Tables)
//{
// DataRow colNames = table.NewRow();
// //foreach (var col in table.Columns)
// //{
// //}
// for (int i = 0; i < table.Columns.Count; i++)
// colNames[i] = table.Columns[i].ColumnName;
// table.Rows.InsertAt(colNames, 0);
//}
foreach (System.Data.DataTable table in ds.Tables)
{
table.Columns.Remove(Inputs.SortColumn);
table.AcceptChanges();
}
stopWatch.Stop(); lbAlert.Text = lbAlert.Text + "\n\n" + "Total Comparison time for B: " + Inputs.RowNoBeforeTable + " x " + Inputs.ColumnNoBeforeTable + " A: " + Inputs.RowNoAfterTable + " x " + Inputs.ColumnNoAfterTable + " is " + stopWatch.ElapsedMilliseconds + " ms, " + stopWatch.ElapsedMilliseconds / 1000 + " s";
return true;
}
【问题讨论】:
-
Excel Interop - Efficiency and performance - 使用
Object[,]在一个操作中读取和写入数据到工作表 - 请参阅此处将您的 DataTable 转换为对象数组 stackoverflow.com/a/30397080/495455。 -
感谢 Jeremy 的推荐。
标签: c# .net excel comparison