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https://issues.apache.org/jira/browse/DERBY-3892?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12636241#action_12636241
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Bryan Pendleton commented on DERBY-3892:
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Here are some starting points for researching performance problems:
http://wiki.apache.org/db-derby/PerformanceDiagnosisTips
Knowing the query plan would be very interesting. To get that, you
may wish to start by trimming your data set down to a smaller number
of records, so that the query runs in a more timely fashion.
You might also wish to post a message to derby-users, rather than
filing a bug, as that might get you more suggestions for how to
improve performance.
> Query execution hangs
> ---------------------
>
> Key: DERBY-3892
> URL: https://issues.apache.org/jira/browse/DERBY-3892
> Project: Derby
> Issue Type: Bug
> Affects Versions: 10.4.1.3, 10.4.2.0
> Environment: OS: Windows Vista
> Application environment: Java 1.5 Swing Application using Derby DB in the
> embedded mode as part of the application.
> Reporter: Georgi Hristov
>
> Having the following db schema:
> CREATE TABLE Messaged_Users (ACCOUNT_ID VARCHAR(20) NOT NULL,
> USER_ID VARCHAR(20) NOT NULL,
> DATE TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
> STATUS INT DEFAULT 0,
> CONSTRAINT PK_ACC_USER_ID PRIMARY KEY (ACCOUNT_ID, USER_ID))
> CREATE TABLE Users (USER_ID VARCHAR(20) NOT NULL CONSTRAINT USER_ID_PK
> PRIMARY KEY,
> USER_NAME VARCHAR(50) NOT NULL)
> with approximately 100,000 records in each table and trying to execute the
> following query:
> PreparedStatement searchStatement = conn.prepareStatement("SELECT
> b.USER_ID, b.USER_NAME FROM Users a JOIN Messaged_Users b ON
> a.USER_ID=b.USER_ID AND a.ACCOUNT_ID=(?)");
> searchStatement.setString(1, "5533232");
> ResultSet foundUsers = searchStatement.executeQuery();
> the executeQuery method actually never ends. I've waited for more than 30
> mins and it didn't finish. I've tried it really many times but without any
> progress the query just hangs. I presume that this is definitely a bug in the
> derby db which should be fixed. Please note also that this fix is very urgent
> for us so that we can deliver our application.
> Thanks in advance for looking into this issue.
>
>
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