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POThere is no difference between using char[] and StringBuilder and string when concatenating strings
 

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  1. POThere is no difference between using char[] and StringBuilder and string when concatenating strings
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    <p>It is said that <code>char[]</code> performs better that <code>StringBuilder</code> and <code>StringBuilder</code> performs better than <code>string</code> in terms of concatenation.</p> <p>In my test there is no significant difference between using <code>StringBuilder</code> and <code>string</code> inside the loop. In fact the <code>char[]</code> is the slowest.</p> <p>I am testing against the same table with 44 columns and 130,000 rows the query is select * from test</p> <p>Can someone help me see if I did something wrong?</p> <p>The following is the code</p> <pre><code>//fetchByString(rd, fldCnt, delimiter, sw); // duration: 3 seconds //fetchByBuilder(rd, fldCnt, delimiter, sw, rsize); // duration: 3 seconds //fetchByCharArray(rd, fldCnt, delimiter, sw, rsize); // duration: 7 seconds private void fetchByString(OracleDataReader pReader, int pFldCnt, string pDelimiter, StreamWriter pWriter) { while (pReader.Read()) { string[] s = new string[pFldCnt]; for (Int32 j = 0; j &lt; pFldCnt; j++) { if (pReader.IsDBNull(j)) { s[j] = ""; } else { s[j] = pReader.GetValue(j).ToString(); // correct value } } pWriter.WriteLine(string.Join(pDelimiter, s)); } } private void fetchByBuilder(OracleDataReader pReader, int pFldCnt, string pDelimiter, StreamWriter pWriter, int pRowSzie) { StringBuilder sb = new StringBuilder(pRowSzie); while (pReader.Read()) { for (Int32 j = 0; j &lt; pFldCnt; j++) { if (pReader.IsDBNull(j)) { //sb.Append(""); sb.Append(pDelimiter); } else { sb.Append(pReader.GetValue(j).ToString()); // correct value sb.Append(pDelimiter); } } pWriter.WriteLine(sb.ToString()); sb.Clear(); } } private void fetchByCharArray(OracleDataReader pReader, int pFldCnt, string pDelimiter, StreamWriter pWriter, int pRowSzie) { char[] rowArray; int sofar; while (pReader.Read()) { rowArray = new char[pRowSzie]; sofar = 0; for (Int32 j = 0; j &lt; pFldCnt; j++) { if (pReader.IsDBNull(j)) { pDelimiter.CopyTo(0, rowArray, sofar, pDelimiter.Length); sofar += pDelimiter.Length; } else { pReader.GetValue(j).ToString().CopyTo(0, rowArray, sofar, pReader.GetValue(j).ToString().Length); sofar += pReader.GetValue(j).ToString().Length; pDelimiter.CopyTo(0, rowArray, sofar, pDelimiter.Length); sofar += pDelimiter.Length; } } string a = new string(rowArray).TrimEnd('\0'); pWriter.WriteLine(a); } } </code></pre>
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    1. This table or related slice is empty.
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    1. USShawn
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
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    1. COPost the code you are profiling with. Is this with or without compiler optimizations? Are you in Debug or Release? There's not enough information here.
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      1. POThere is no difference between using char[] and StringBuilder and string when concatenating strings
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    2. COHow much time is spent in `OracleDataReader` methods?
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      1. POThere is no difference between using char[] and StringBuilder and string when concatenating strings
      1. USMiserable Variable
    3. COYou are not going to get any useful information from these tests. You have IO operations happening alongside the concatenation tests you are attempting to 'profile'.
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      1. POThere is no difference between using char[] and StringBuilder and string when concatenating strings
      1. USPerception
 

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