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Date: Fri, 22 Sep 2006 14:38:24 -0700 (PDT)
From: "Knut Anders Hatlen (JIRA)" <derby-dev@db.apache.org>
To: derby-dev@db.apache.org
Subject: [jira] Commented: (DERBY-1876) Investigate overhead of JDBC layer
 and compiled activation code for simple embedded read-only, forward
 ResultSets
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    [ http://issues.apache.org/jira/browse/DERBY-1876?page=comments#action_12437015 ] 
            
Knut Anders Hatlen commented on DERBY-1876:
-------------------------------------------

To get an impression of the allocation/gc cost for the statistics, I made all the runtime statistics fields in BasicNoPutResultSetImpl, RowResultSet and UnionResultSet static (these are the ResultSet classes used by the query in derby1867.java). I ran derby1876.java ten times with and ten times without the changes. On average, the test used 15% less time with static fields on Solaris, JVM 1.6. On FreeBSD, JVM 1.5, the time spent was 20% lower with static fields.

> Investigate overhead of JDBC layer and compiled activation code for simple embedded read-only, forward ResultSets
> -----------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-1876
>                 URL: http://issues.apache.org/jira/browse/DERBY-1876
>             Project: Derby
>          Issue Type: Improvement
>          Components: JDBC, Performance
>            Reporter: Daniel John Debrunner
>            Priority: Minor
>         Attachments: derby1862.java, derby1876.java
>
>
> For simple ResultSet usage like:
> ResultSet rs = ps.executeQuery();
>       while (rs.next()) {
>               rs.getInt(1);
>               rs.getInt(2);
>               rs.getInt(3);
>        }
> rs.close();
> it would be interesting to see how much overhead could be removed with simple changes, or possibly removed if there was a simple ResultSet implementation for forward only, read-only ResultSet, and the more complete implementation for all other ResultSet types such as updateable and/or scrollable. Has introducing updateable ResultSets, for example, degraded the performance of read-only ResultSets? Could code be changed so that a typical read-only Resultset is not affected by the code required for richer ResultSets?

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