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POJava Program Speed database connection
 

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  1. POJava Program Speed database connection
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    <p>I've finished writing my first java program that accesses a database and allows me to remote onto machines.</p> <p>This works ok when I run it from my own machine (which also hosts the database it connects to). However, if I use it on another machine and connect to the database the program hangs considerably while it does the database task.</p> <p>I expected it to be a small wait, however sometimes it can take afew miniutes before it finish's the task at hand.</p> <p>Heres one of the tasks that it hangs on.</p> <pre><code> public void ChangeSite() throws Exception{ ConnectionPoolS demo = new ConnectionPoolS(); DataSource dataSource = demo.setUp(); Connection conn = null; PreparedStatement stmt = null; String Site = (String)Sites.getSelectedItem(); jProgressBar.setIndeterminate(true); jProgressBar.setStringPainted(true); jProgressBar.setString("Searching..."); int sRecordNo; sRecordNo = 0; String IpAddress = null, IpRange = null, Atvisionpw = null, Port = null, Practice = null, Surgery = null; try { conn = dataSource.getConnection(); stmt = conn.prepareStatement("SELECT * FROM Customer WHERE Practice = '"+Site+"' and BRANCH = 'N'"); ResultSet rs = stmt.executeQuery( ); while (rs.next()) { sRecordNo = sRecordNo + 1; Surgery = rs.getString("SURGERY"); Practice = rs.getString("PRACTICE"); IpAddress = rs.getString("IPADDRESS"); Port = rs.getString("PORT"); Atvisionpw = rs.getString("ATVISIONPW"); IpRange = rs.getString("IPRANGE"); } if (sRecordNo == 1){ SiteIp.setText(IpAddress); Password.setText(Atvisionpw); PcIp.setText(IpRange); } else if (sRecordNo &gt; 1){ Multisite(); } jProgressBar.setIndeterminate(false); jProgressBar.setString(""); stmt.close(); conn.close(); } </code></pre> <p>This is all on a derby database.</p> <p>What I am doing wrong? I am missing something? Is there a way I can run some kind of performance check on this to find out what exactly is causing it to hang while running the database task, as this is all internal on an internal network I wouldn't expect to be waiting as much as I am!</p> <p>Edit: With some help from Stefan (Thanks a bunch) ive found that that using the break points it seems hang after running the line</p> <pre><code>conn = dataSource.getConnection(); </code></pre> <p>the next line after that is now </p> <pre><code>stmt = conn.prepareStatement("SELECT * FROM Customer WHERE Practice = '"+Site+"' and BRANCH = 'N'"); </code></pre> <p>but it only hangs after running the Connection line so would this mean the connection to the physical database is causing the hang?</p> <p>Edit2: I have now setting a Connection Pool, however its still hanging when connecting, im at a bit of a loss now!, would a different engine provide better results?</p>
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    1. USChristopher Lewis
    1. USChristopher Lewis
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    1. COHow good is the network connection? Check out with `ping`.
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      1. USPeterMmm
    2. COis the size of the DB considerably different and indexes are lacking? At what stage is it hanging?
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      1. USScary Wombat
    3. COWhat happens if you execute the SQL query manually, and how many records are there in this table? Also, you can try setting a breakpoint at the first line of your `ChangeSite` method to step over every line. You can then figure out where your performance issue is at.
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      1. USStefan
 

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