Hi,
Is there an upper-bound on the memory required to run
syscs_util.syscs_compress_table? What determines how much memory is
required (for example, should it be fixed or proportional to table
size? affected by page size or page cache size?) We're occasionally
getting out of memory
?
On Wed, Nov 5, 2008 at 7:31 PM, Jim Newsham [EMAIL PROTECTED]
wrote:
No need for manual deletion or an external script... just clear out the
database in your test tear-down code. Here is our strategy (junit 4.x):
- Before all test cases (@BeforeClass): Generate a temporary directory
No need for manual deletion or an external script... just clear out the
database in your test tear-down code. Here is our strategy (junit 4.x):
- Before all test cases (@BeforeClass): Generate a temporary directory
randomly; create a database there, to be used by tests.
- After each test case
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Thursday, October 23, 2008 5:26 AM
To: Derby Discussion
Subject: Re: excessive disk space allocation
On 23.10.08 02:26, Jim Newsham wrote:
Hasn't been a lot of response to this thread. I have a 23gb
to the real problem.
Thanks,
Jim
-Original Message-
From: Jim Newsham [mailto:[EMAIL PROTECTED]
Sent: Tuesday, October 21, 2008 11:21 AM
To: 'Derby Discussion'
Subject: RE: excessive disk space allocation
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL
Hi,
I'm doing some benchmarking of our application which stores data in derby.
The parts of the application which I am exercising only perform inserts, not
deletes. The results suggest that derby disk space allocation is excessive,
particularly because compressing the tables reduces the
I want to change a column from generated always as identity to generated
by default as identity. Do I have to remove/read the column, or is there
an easier way to do it?
Thanks,
Jim
-Original Message-
From: Christos Vasilakis [mailto:[EMAIL PROTECTED]
Sent: Friday, August 29, 2008 12:46 AM
To: Derby Discussion
Subject: Re: RE : Maximum amount of data suitable for Derby
Benoît Chaluleau wrote:
Voilà un défi ! Etre les premiers à avoir planté Derby par
It looks to me like an external process is getting a lock on the file, which
prevents Derby/Java from accessing it. The hints are:
(a) the error message is generated in native code (at
java.io.RandomAccessFile.open(Native Method))
(b)searching google for the exact error message
as I understand it, when you insert a row into a table with an
identity column, it has to lock syscolumns to update the identity value -
from the docs:
Derby keeps track of the last increment value for a column in a cache. It
also stores the value of what the next increment value will
Google is your friend: http://www.google.com/search?hl=en
http://www.google.com/search?hl=enq=database+indexbtnG=Google+Search
q=database+indexbtnG=Google+Search. For example, try:
http://en.wikipedia.org/wiki/Index_(database).
Jim
_
From: Chris [mailto:[EMAIL PROTECTED]
Does anyone have insight into how the import would compare to the
drop/recreate workaround, performance-wise? I'm currently using
drop/recreate for a large number of tables, so just wondering if it would be
worth trying import.
Regarding holding up the truncate feature because of lack of
Load the data in Java code, using a while loop. If a particular insert
fails, check the SQLState code. If it is code 23505, ignore the exception
and continue with the next iteration of the loop, otherwise re-throw the
exception.
Jim
-Original Message-
From: Geter [mailto:[EMAIL
when i run both the programs:i get the following exception:mhjfdshmnjh
java.sql.SQLTransactionRollbackException: A lock could not be obtained
within the time requested
The problem is that database writes in one client acquire row or table
locks, which prevent the other client from accessing
Although Derby doesn't immediately release space freed up by deleted
records, it will eventually re-use that space (when new records are
inserted). So the issue that you have is really only a problem if you are
deleting a large number of records at once and you need that space back
immediately.
I have been seeing this same problem (very) intermittently as well... just
have been way too busy with other things at the time to look into it. When
it occurs, I generally see a NullPointerException on commit, and subsequent
usage of the (statement? connection? data source? not sure exactly)
the problem.
-Eric
-Original Message-
From: Jim Newsham [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 13, 2008 2:30 PM
To: 'Derby Discussion'
Subject: RE: NullPointerException in Derby driver (from at least
10.2.2.0)
I have been seeing this same problem (very
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Thursday, January 31, 2008 10:23 PM
To: Derby Discussion
Subject: Re: names of columns in VALUES
Jim Newsham [EMAIL PROTECTED] writes:
From: Army [mailto:[EMAIL PROTECTED]
[...]
So maybe try
-generated sql I produce, it would save
some special casing and code contortion. But this one is minor. the
renaming would be much more helpful.
Regards,
Jim Newsham
-Original Message-
From: Army [mailto:[EMAIL PROTECTED]
Sent: Wednesday, January 30, 2008 9:20 AM
To: Derby Discussion
Subject: Re: names of columns in VALUES
Jim Newsham wrote:
It seems there is no way to name the columns produced by the VALUES
keyword.
snip
Select
OntologyDefinedValueString otValue = createOntologyDefinedValue(rs2);
...does the createOntologyDefinedValue(ResultSet) method close the result
set?
Jim
-Original Message-
From: Eduardo S.E. de Castro [mailto:[EMAIL PROTECTED]
Sent: Monday, December 17, 2007 10:17 AM
To: Derby
Here are some ideas:
- Use a single prepared statement. Derby generates a new Java class for
each sql statement, which is costly, so using a single statement is a lot
faster.
- Use a single transaction (disable auto-commit, and commit just once when
you are done inserting).
- Use batch inserts.
In JDBC, column indices start at 1.
-Original Message-
From: digi_pixel [mailto:[EMAIL PROTECTED]
Sent: Wednesday, December 05, 2007 10:46 AM
To: derby-user@db.apache.org
Subject: SqlException With Returning Data For First Row
When running my Java program a SqlException is
You should read a book or tutorial on JDBC.
When you retrieve a resultset in its initial state, the cursor is positioned
before the first row. You need to use ResultSet.first() or
ResultSet.next(), and check the return value to see whether you're actually
on a valid record.
Jim
-Original
Hi,
Using Derby 10.3.1.4, we had an intermittent transaction failure with error
message A SAVEPOINT with the passed name already exists in the current
transaction, which appears to be caused internally by Derby. I see that
there are four JIRA issues which relate to this particular error
-Original Message-
From: Bryan Pendleton [mailto:[EMAIL PROTECTED]
Sent: Friday, September 28, 2007 11:40 AM
To: Derby Discussion
Subject: Re: A SAVEPOINT with the passed name already exists in the
current transaction
see that there are four JIRA issues which relate to this
A primary key can be compound (it can be comprised of multiple columns), but
there can only be one primary key per table.
_
From: first last [mailto:[EMAIL PROTECTED]
Sent: Thursday, June 21, 2007 10:25 AM
To: derby-user@db.apache.org
Subject: Documentation error in Derby
/DERBY-2689
Regards,
Jim Newsham
again. Does this mean it would be wasteful
to increase the page cache size?
Thanks,
Jim Newsham
Joda-time is an open source (Apache license) project for representing
times... intended to do a better job than the java.util.Date and Calendar
classes. Actually there is a current JSR for improving the date/time
support in the JDK, headed up by the lead joda-time developer, but I
digress.
I'm
-Original Message-
From: Bryan Pendleton [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 10, 2007 9:58 AM
To: Derby Discussion
Subject: Re: Executing command from a file via JDBC
I didn't want to distribute derbytools.jar with my application. I guess
was looking for something
be
guaranteed to parse correctly.
-Original Message-
From: Jim Newsham [mailto:[EMAIL PROTECTED]
Sent: Monday, May 14, 2007 5:22 PM
To: 'Derby Discussion'
Subject: RE: Executing command from a file via JDBC
I had a need to run sql scripts into our database at runtime as well. I
a file via JDBC
Jim Newsham wrote:
-Original Message-
From: Bryan Pendleton [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 10, 2007 9:58 AM
To: Derby Discussion
Subject: Re: Executing command from a file via JDBC
I didn't want to distribute derbytools.jar with my application
-Original Message-
From: Bryan Pendleton [mailto:[EMAIL PROTECTED]
Sent: Tuesday, March 27, 2007 5:42 AM
To: Derby Discussion
Subject: Re: INPLACE Table Compression
Inplace Compression utility, no disk space is recovered and the size
of the *.dat files is not reduced.
That
, Jim Newsham [EMAIL PROTECTED] wrote:
Is there any particular reason that the built-in system procedure for
backing up a database doesn't back it up to the directory I specify, but to
a subdirectory of the directory I specify? For example, if my database is
in a directory called c:\a\b and I
Is there any particular reason that the built-in system procedure for
backing up a database doesn't back it up to the directory I specify, but to
a subdirectory of the directory I specify? For example, if my database is
in a directory called c:\a\b and I request to back it up to c:\d, it puts
Thank you Suresh for the explanation, it was very helpful. I filed a JIRA
request for documentation improvement.
Regards,
Jim
failures for that transaction were. I did see
logged retries for other insert transactions, but no stack trace, indicating
that those eventually succeeded.
Regards,
Jim Newsham
_
From: Jim Newsham [mailto:[EMAIL PROTECTED]
Sent: Tuesday, February 20, 2007 12:20 PM
To: 'Derby Discussion'
Subject: Container 2,385 not found
Hi,
I got a curious error message and was wondering if there was an explanation
for the cause, or if this was due to a bug
Hello,
I'd like to back up an online derby database, and would also like to
understand how this interacts with other concurrent transactions (regarding
visibility, blocking, etc.). I found some documentation in derbyadmin.pdf.
It mentions logged and unlogged operations, but doesn't
Army wrote:
In order to get Derby to recognize the equijoin predicate, the subquery
has to appear in the FROM list. So I created a view for the subquery:
snip view
and then I changed the query to select and join with that view:
snip
Working off the modified query above I
Hi everyone, and thanks Army for your detailed response. My responses are
interspersed below...
-Original Message-
From: Army [mailto:[EMAIL PROTECTED]
Sent: Friday, November 10, 2006 6:53 AM
To: Derby Discussion
Subject: Re: slow subqueries
Jim Newsham wrote:
Why do queries
This is why a nested loop is not going to work here... 20,000 squared
operations is very expensive, let alone millions squared. For a query
with
this profile, the inner query should only be executed once.
Perhaps you can get the behavior you desire by explicitly creating
a temporary
+Official+Release
There have been some fixes in the related code generation areas for 10.2:
DERBY-766, DERBY-1714 etc.
Also, can post the schema that can reproduce this issue ?
Regards,
Rajesh
Jim Newsham wrote:
Hi everyone,
I thought the problem would go away if I gave
Any reason why I should get a stack overflow error with the following query?
Yes, I know the query is a bit odd... it's not hand-written. The query
generator could be optimized. Nevertheless... is the stack overflow here
considered a bug or a limitation? If limitation, what specifically is
)
at
com.referentia.sdf.monitor.samplebase.derby.QueryDataSet.getSize(QueryDataSe
t.java:139)
-Original Message-
From: Jim Newsham [mailto:[EMAIL PROTECTED]
Sent: Monday, November 06, 2006 11:21 AM
To: 'Derby Discussion'
Subject: StackOverflowError
Any reason why I should get
Hi,
Id like to create a hierarchical table which
references itself and enforces uniqueness. For example:
create table node (
id int not null generated always as
identity primary key,
name varchar(32) not null,
fk_parent_id int,
unique (name, fk_parent_id),
foreign key
From: Jim Newsham
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, October 24, 2006
12:18 PM
To: 'Derby Discussion'
Subject: hierarchical table with
unique constraint
Hi,
Id like to create a hierarchical table which
references itself and enforces uniqueness. For example:
create table node
Hi,
Is there a jira issue for adding a limit statement (to limit
the number of records returned) to a select statement? I did a jira search but
could find no such issue. Id like to vote for it.
I also searched the mailing list for discussions regarding
this feature, and responses
If you are embedding Derby, then regarding distribution you would
follow the same procedure as for any other third party Java library. If you
want help doing that in Netbeans, then your question really should be addressed
to the Netbeans mailing list. To put it briefly:
Edit
Rajesh,
Thanks for the update on DERBY-756.
Regarding DERBY-912, I recognize that its a subtask of 756, nevertheless
756 is reported as fixed while 912 is still open. Is 912 expected to be fixed
by v10.2 also?
Thanks,
Jim Newsham
From: Rajesh Kartha
[mailto:[EMAIL
testing.
Thanks,
Jim Newsham
of?
Would you recommend Derby
for my project?
Thanks,
Jim Newsham
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