📄 performance.html
字号:
<html>
<head>
<meta name="KEYWORDS" content="
library, C++,
Oracle, SQLServer, DB2, Sybase, Informix, InterBase, SQLBase, ODBC,
SQL, server, client, database, programming, development, software,
Win32, Windows, Linux, Unix, Solaris,
Microsoft, Borland, Centura, Gupta, IBM">
<meta name="DESCRIPTION" content="SQLAPI++ is C++ library for accessing SQL databases (Oracle, SQLServer, Sybase, DB2, InterBase, SQLBase, Informix, ODBC).
It uses native APIs, provides low-level access to database-specific features.">
<title>SQLAPI++ Library - How To - Optimizing Database Performance</title>
</head>
<body bgcolor="#ffffff" BACKGROUND="../images/bg.gif" text="#000000"><!--class="GlbHdr"-->
<table WIDTH="600" height="40" frame="hsides" BORDER="2" BORDERCOLOR="#004fcd" align="right" cellpadding="0" cellspacing="2" id="TABLE1">
<tr><!--class="GlbDefault"-->
<td width="70" bgcolor="#000094" bordercolor="black" align="middle"><A href="../index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>Home</b></font></A></td></TD>
<!--class="GlbActive"-->
<td width="70" bgcolor="#00bb00" bordercolor="black" align="middle"><A href="index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>How To</b></font></A></td>
<!--class="GlbDefault"-->
<td width="70" bgcolor="#000094" bordercolor="black" align="middle"><A href="../OnLineDoc/index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>Online Documentation</b></font></A></td><!--class="GlbDefault"-->
<td width="70" bgcolor="#000094" bordercolor="black" align="middle"><A href="../Support/index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>Support</b></font></A></td>
<td width="70" bgcolor="#000094" bordercolor="black" align="middle"><A href="../Download/index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>Download</b></font></A></td>
<td width="70" bgcolor="#000094" bordercolor="black" align="middle"><A href="../Order/index.html" style="TEXT-DECORATION: none">
<font color="white" size="3" face="sans-serif">
<b>Order</b></font></A></td>
</tr>
</table>
<p> </p>
<p> </p>
<table width="100%" cellpadding="1" cellspacing="1">
<tr>
<td valign="top" align="left"><!--class="LeftMenu"-->
<table frame="void" CELLSPACING="2" cellpadding="2" width="165">
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="connect.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Connecting to databases</font></A> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="transactions.html" style="TEXT-DECORATION: none">
<font color="white" face="sans-serif" size="2">
Transactions</font></A> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="commands.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Executing an SQL command</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="procedures.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Executing stored procedures</A>
</FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="bind.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Binding input parameters</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="fetch.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Fetching result set</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="fetch_multiple.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Fetching multiple result sets</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/red.gif" WIDTH="12" HEIGHT="12"
>
<A href="performance.html" style ="TEXT-DECORATION: none" >
<font color="white" size="2" face="sans-serif">
Optimizing Database Performance</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="return_param.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Returning output parameters</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12" alt ="" border="0" hspace="0" style ="HEIGHT: 12px; WIDTH: 12px" useMap="">
<A href="blobs.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Working with
Long or Lob(CLob, BLob) Data</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12"><A href="datetime.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Working with date/time values</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="errors.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Error handling</A> </FONT> </td>
</tr>
<tr>
<td><img align="middle" src="../images/green.gif" WIDTH="12" HEIGHT="12">
<A href="query_exampl.html" style="TEXT-DECORATION: none">
<font color="white" size="2" face="sans-serif">
Query examples</A> </FONT> </td>
</tr>
</table>
</td>
<td width="30">
<p> </p>
</td>
<td valign="top">
<center>
<h1> Optimizing Database
Performance</h1>
</center>
<p>
The
goal of performance tuning is to minimize the response time for each
query.</p>
<p>One of the ways to accelerate transactions
is minimizing expensive network traffic
between the server and client. It
can be useful when working with recordsets with a great number of
rows.</p>
<p>SQLAPI++ Library provides support for
<EM>bulk row fetching</EM>, which means that multiple records can be
retrieved at once during a single fetch, rather than retrieving one
record at a time from the data source. To set bulk row fetching you
should set <STRONG>PreFetchRows</STRONG>
<A href="../OnLineDoc/Command_setOption.html">command option</A>
before the command execution. It is safe to use
<STRONG>PreFetchRows</STRONG>
option in any DBMS. If
DBMS does not support bulk row fetching then this option will be
ignored.</p>
<p>The value of <STRONG>PreFetchRows</STRONG>
option specifies how many rows you wish to retrieve during a single
fetch when
using bulk row fetching. The default
value is "1"; it means that you are not using bulk row
fetching.</p>
<p>
See <A
href="../Examples/bulk_fetch.cpp">Example</A>
to compare time expended on fetching rows with and without bulk
mode.</p>
<h3>Problems and Questions</h3>
<p>If you don't find the answer to you questions or have some problems on
using the Library, please, send e-mail to <A href="mailto:howto@sqlapi.com">howto@sqlapi.com</A>. </p>
<p> </p>
</td>
<tr></tr>
</table></FONT>
</body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -