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<td width="90%"><font size="4" face="Verdana, Arial, Helvetica"><b>JDBC <code style="font-family: Courier New, Courier, monospace; font-size: 18">Connection</code> 方法</b></font></td><td width="200" align="right"><font size="1" face="Verdana, Arial, Helvetica"><nobr>   第 2 頁(yè)（共2 頁(yè)）</nobr></font></td>
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<code>Connection</code> 或 <code>PooledConnection</code> 對(duì)象也有幾種方法可以用于直接或間接地提高系統(tǒng)性能。首先，假定 JDBC 驅(qū)動(dòng)程序和底層數(shù)據(jù)庫(kù)支持它，連接對(duì)象可以設(shè)置為只讀 — <code>setReadOnly()</code>。這可以為不需要作數(shù)據(jù)庫(kù)修改的應(yīng)用程序提高系統(tǒng)性能，因?yàn)閿?shù)據(jù)庫(kù)不需要擔(dān)心緩存新頁(yè)面、維護(hù)日志條目或者獲取任何數(shù)據(jù)上的寫入鎖。
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其它兩個(gè)有點(diǎn)關(guān)系的方法是 <code>setAutoCommit()</code> 和 <code>setTransactionIsolation()</code> 方法，以前曾經(jīng)在中討論過(guò)。因?yàn)槭聞?wù)的錯(cuò)誤管理會(huì)引起某些最大的數(shù)據(jù)庫(kù)性能損失，所以應(yīng)該清楚地理解這些方法和它們的影響，然后再謹(jǐn)慎地應(yīng)用它們。
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最后，<code>nativeSQL()</code> 方法是一個(gè)經(jīng)常被忽略的方法，它將一個(gè)給定的 SQL 查詢翻譯成底層數(shù)據(jù)庫(kù)的自身查詢語(yǔ)言。通過(guò)檢查您的查詢的自身 SQL 版本，您也許能夠更好地理解數(shù)據(jù)庫(kù)是如何解釋您的查詢的，從而可以對(duì)應(yīng)用程序作適當(dāng)?shù)男薷囊蕴岣哒w性能。
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