Binary | control | data | Database mode one: for small volumes of data, a load of memory, one-time access
<summary>
Small capacity attachment data read performance test
</summary>
<param name= "strSQL" ></param>
<returns></returns>
public static bool Processdatafromdatabasebyadapter (string Strsql,out string strerr)
{
Long T0 = Environment.tickcount;
DataTable table;
if (! Oledatabaseproxy.executesql (strsql,out table,out strerr)) return false;
Long Imagedatasizecount = 0;
if (! Capabilityproxy.processdatafromdatabase (ref table,out imagedatasizecount,out Strerr)) return false;
Long T1 = Environment.tickcount;
Logproxy.writelog ("Database performance test: Total time consuming" + convert.tostring (t1-t0) + "MS, data Volume:" + imagedatasizecount.tostring () + "bytes");
Strerr = "";
return true;
}
<summary>
Performing a data query operation
</summary>
<param name= "strSQL" ></param>
<param name= "Table" ></param>
<param name= "Strerr" ></param>
<returns></returns>
public static bool ExecuteSQL (string strsql,out System.Data.DataTable table,out string strerr)
{
System.Data.OleDb.OleDbConnection Cnn = new OleDbConnection ();
cnn.connectionstring = Configproxy.getvaluebykey ("oleconnectionstring");
System.Data.OleDb.OleDbDataAdapter adapter = new OleDbDataAdapter (STRSQL,CNN);
Table = new System.Data.DataTable ();
Try
{
Adapter. Fill (table);
}
catch (Exception ERR)
{
Strerr = Err.message;
return false;
}
Strerr = "";
Releasing resources
Cnn.dispose ();
Adapter. Dispose ();
Gc. Collect ();
return true;
}
<summary>
Processing database records
</summary>
<param name= "Table" ></param>
<param name= "Imagedatasizecount" ></param>
<param name= "Strerr" ></param>
<returns></returns>
private static bool Processdatafromdatabase (ref DataTable table,out long imagedatasizecount,out string strerr)
{
Imagedatasizecount = 0;
for (int i = 0;i < table. Rows.count;i + +)
{
byte [] imagecontent = (byte[]) table. rows[i]["attachment content"];
Imagedatasizecount + = convert.toint64 (table. rows[i]["attachment capacity"]);
Capabilityproxy.processimagedata (ref imagecontent);
}
Strerr = "";
return true;
}
Mode two: online, according to the specified size of the segment to get
<summary>
Reading performance test of bulk attachment data
</summary>
<param name= "strSQL" ></param>
<returns></returns>
public static bool Processdatafromdatabasebyreader (string Strsql,out string strerr)
{
Long T0 = Environment.tickcount;
Long Imagedatasizecount = 0;
System.Data.OleDb.OleDbCommand cmd = new OleDbCommand ();
OleDbConnection Cnn = new OleDbConnection (Configproxy.getvaluebykey ("oleconnectionstring"));
Cmd. Connection = Cnn;
Cmd.commandtext = strSQL;
OleDbDataReader reader;
Open connection
Try
{
Cnn.open ();
}
catch (Exception ERR)
{
Strerr = Err.message;
return false;
}
byte[] pixels = new Byte[numpixels];
Long readcount = 0;
reader = cmd. ExecuteReader ();
Process-by-article
while (reader. Read ())
{
for (long i = 0; i< convert.toint64 reader. GetString (7)); i = i + numpixels)
{
Readcount = reader. GetBytes (6,i,pixels,0,numpixels);
if (readcount = 0)
{
Break
}
else if (Readcount = = numpixels)
{
Processimagedata (ref pixels);
}
Else
{
Byte[]buff = new Byte[readcount];
Processimagedata (ref buff);
}
Imagedatasizecount + = Readcount;
}
}
Reader. Close ();
Close connection
if (cnn.state = = System.Data.ConnectionState.Open)
{
Cnn.close ();
}
Long T1 = Environment.tickcount;
Logproxy.writelog ("Database performance test: Total time consuming" + convert.tostring (t1-t0) + "MS, data Volume:" + imagedatasizecount.tostring () + "bytes");
Releasing resources
Cnn.dispose ();
Cmd. Dispose ();
Gc. Collect ();
Strerr = "";
return true;
}
<summary>
Buffer size
</summary>
public static int numpixels = Int. Parse (Configproxy.getvaluebykey ("buffersize"));
<summary>
Processor Latency
</summary>
public static int processimagerepeats = Int. Parse (Configproxy.getvaluebykey ("Cpulatetime"));
Comparison of two ways:
The first way: Reduce database pressure, data size known
The second way: increase database pressure, unknown data size
Summarize:
According to the actual application of the choice, in the binary field content size is known, the database burden pressure than the case to choose the first way; in the case of the binary field, the content size is unknown, and the database burden is less stressful, choose the second way.
