[
https://issues.apache.org/jira/browse/DERBY-6975?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16233547#comment-16233547
]
David Sitsky commented on DERBY-6975:
-------------------------------------
Hi Rick - many thanks for your reply.
I haven't tried changing derby.language.sequence.preallocator, what should I
change it to?
For 2) - only a single thread is accessing the DB.
We are using calls such as below:
{code}
try (PreparedStatement ps = connection.prepareStatement("INSERT INTO
table (col1, col2, name) VALUES (?, ?, ?)",
Statement.RETURN_GENERATED_KEYS))
{code}
and then retrieving the ID of the row using this sort of code:
{code}
public static int getGeneratedIntKey(Statement statement) throws
SQLException
{
try (ResultSet rs = statement.getGeneratedKeys())
{
if (rs == null)
{
throw new IllegalStateException("Caller forgot to pass
Statement.RETURN_GENERATED_KEYS");
}
if (rs.next())
{
return rs.getInt(1);
}
else
{
throw new IllegalStateException("Caller did not perform an
update");
}
}
}
{code}
For the tables, we use an id field as follows:
{noformat}
" id INTEGER PRIMARY KEY GENERATED BY
DEFAULT AS IDENTITY NOT NULL," +
{noformat}
For 4) - yes as you can see in the code above. For 5) no code calls
SYS.SYSSEQUENCES.
> ERROR 40XL1: A lock could not be obtained within the time requested
> --------------------------------------------------------------------
>
> Key: DERBY-6975
> URL: https://issues.apache.org/jira/browse/DERBY-6975
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.14.1.0
> Reporter: David Sitsky
> Priority: Major
>
> I have an application that when run on a certain dataset, every 5 runs I
> might see this error happening. The code is creating a lot of rows using a
> sequence generator.
> {noformat}
> Caused by: ERROR 40XL1: A lock could not be obtained within the time
> requested
> at
> org.apache.derby.iapi.error.StandardException.newException(StandardException.java)
>
> at
> org.apache.derby.iapi.error.StandardException.newException(StandardException.java)
>
> at
> org.apache.derby.impl.sql.catalog.SequenceUpdater.tooMuchContentionException(SequenceUpdater.java)
>
> at
> org.apache.derby.impl.sql.catalog.SequenceUpdater.getCurrentValueAndAdvance(SequenceUpdater.java)
>
> at
> org.apache.derby.impl.sql.catalog.DataDictionaryImpl.getCurrentValueAndAdvance(DataDictionaryImpl.java)
>
> at
> org.apache.derby.impl.sql.execute.BaseActivation.getCurrentValueAndAdvance(BaseActivation.java)
>
> at
> org.apache.derby.impl.sql.execute.InsertResultSet.getSetAutoincrementValue(InsertResultSet.java)
>
> at
> org.apache.derby.impl.sql.execute.BaseActivation.getSetAutoincrementValue(BaseActivation.java)
>
> at
> org.apache.derby.exe.ac560740aax015fx6bc1x68cax000002339e626a.e0(ac560740aax015fx6bc1x68cax000002339e626a.java)
>
> at
> org.apache.derby.impl.services.reflect.DirectCall.invoke(DirectCall.java)
> at
> org.apache.derby.impl.sql.execute.RowResultSet.getNextRowCore(RowResultSet.java)
>
> at
> org.apache.derby.impl.sql.execute.NormalizeResultSet.getNextRowCore(NormalizeResultSet.java)
>
> at
> org.apache.derby.impl.sql.execute.DMLWriteResultSet.getNextRowCore(DMLWriteResultSet.java)
>
> at
> org.apache.derby.impl.sql.execute.InsertResultSet.getNextRowCore(InsertResultSet.java)
>
> at
> org.apache.derby.impl.sql.execute.InsertResultSet.open(InsertResultSet.java)
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.executeStmt(GenericPreparedStatement.java)
>
> at
> org.apache.derby.impl.sql.GenericPreparedStatement.execute(GenericPreparedStatement.java)
>
> ... 25 more
> {noformat}
> It is not clear to me why when looking at the code this should be happening.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
