Hi,
> Is there anyway to use same connection without trying to get the connection
> every time in the spring? I know it is outside but if you know please let me
> know.
You should use a 'real' connection pool. See
http://static.springsource.org/spring/docs/2.5.x/api/org/springframework/jdbc/dat
Thomas,
From the thread dump I found that "pool-2-thread-43" &
"pool-2-thread-110" are on same database. So it make sense to
"pool-2-thread-43" is blocked by "pool-2-thread-110".
DriverManager.java synchronized on
private static synchronized Connection getConnection(
String url, java.ut
Thomas,
Here is the thread dump. All the threads are blocked on
"pool-2-thread-43" which is blocked by "pool-2-thread-110"
"pool-2-thread-50" - Thread t@88
java.lang.Thread.State: BLOCKED on java.lang.Class@1308abb owned by:
pool-2-thread-43
at java.sql.DriverManager.getConnectio
Thomas,
I am in the assumption that if I use separate database for each table
the syn on the executeQuery should do only database.
But when I look at the thread-dump all the queries are blocked by single
thread (even they are on different database).
Here are the connection urls of each db.
Hi,
> Can I create separate data base for each table? The tables are not
> related to each other.
> Can this help?
Yes, I believe this would help.
Regards,
Thomas
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Thomas,
Can I create separate data base for each table? The tables are not
related to each other.
Can this help?
Thanks,
Suresh
On Fri, Mar 4, 2011 at 5:39 PM, suresh kumar wrote:
> Thomas,
>
>
> > Does the update statement use an index? To find out, use EXPLAIN UPDATE
> ...
> Yes it
Thomas,
> Does the update statement use an index? To find out, use EXPLAIN UPDATE
...
Yes it uses.
> Is the update performance OK if there are no queries running?
Yes if there are no or few queries then the update performance is good.
Thanks,
Suresh
On Thu, Mar 3, 2011 at 1:02 AM, Thomas Muel
Hi,
> The above query took more than 1 sec per row update.
Does the update statement use an index? To find out, use EXPLAIN UPDATE ...
> I would like to know why the updating the table with 3k rows taking longer
> time when concurrent read requests are there?
> Is there any configuration setting
Hi Thomas,
Actually first one is ATTR1 not ATTR2, typo error when changing the actual
column names.
WHERE ATTR1 = 9 AND ATTR2 IN () AND ATTR4 IN (.)
The use cause is for reporting. we have web application and we should
present data in graphs and tables. "n" number of concurrent users
Hi,
Are you completely sure this is the query?
WHERE ATTR2 = 9 AND ATTR2 IN ()
This sounds like it would never return rows?
No matter if that's correct or not, why do you use such a large list
of IN() values? I could optimize the code for this case, and I will
add it to the roadmap. However, I
Hi Thomas,
I have verified the queries with EXPLAIN ANAYLYZE, the queries are
using right indexes.
Here I am giving the query sample and schema structure.
Query sample:
SELECT ATTR1, MAX(ATTR10) AS ATTR10, SUM(ATTR11) AS ATTR11,SUM(ATTR12) AS
ATTR12, SUM(ATTR13)
Hi,
It looks like you are using a query that contains a condition of the
form "column IN (...)". This query seems to be slow. I guess you need
to analyze your application and check if the right indexes exist.
Obviously, I can't say what is slow and why because I don't have your
application. See al
Hi,
I guess the mail from Eliran Bivas (CHARACTER SET) was simply in the
wrong thread.
Regards,
Thomas
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Hi,
Could you use the profiling tool to find out what is taking so long? To use it:
org.h2.util.Profiler prof = new org.h2.util.Profiler();
prof.interval = 1;
prof.startCollecting();
// ... your code ... //
System.out.println(prof.getTop(10));
I have some guesses (maybe you don't use prepared st
Hi,
Try to use hash index on a single column with the most unique values
(of course this column should be in where clause).
But better use profiler and find where h2 spends time. Also may be you
should use your own data structures instead of database if it is
possible in your case.
regards,
Sergi
Panayiotis Vlissidis,
I am using prepared statements, even I tried with batch updates (with
statement, couldn't use prepared statement in batch updates).
The difference in db size after adding multi-column index is 1 KB.
Thanks,
Suresh
On Tue, Feb 15, 2011 at 2:04 PM, Panayiotis Vlissidis
Hello,
Thanks for the update and nice to know it worked.
Sorry to hear that it's still above 1 sec, maybe someone else
can provide more suggestions.
You should also have a look here:
http://www.h2database.com/html/performance.html#database_performance_tuning
The easiest things to start with(in c
Eliran,
Sorry, i didn't get your question on script and CHARACTER SET.
if you are taking about \n\t\t, the sql scripts are externalized in
the a config file. It has new lines and tabs in the query.
Thanks,
Suresh
On Feb 14, 8:38 pm, Eliran Bivas wrote:
> As you probably can tell, this is
Panayiotis Vlissidis,
Thanks a lot for the reply. I made the changes as you suggested.
Created multi-column indexes.
The time taken to update the table is 1.5 sec instead of 2 sec with
MULTI_THREADED=1.
Thanks,
Suresh
On Feb 14, 6:36 pm, suresh wrote:
> Hi,
>
> I am using in-
As you probably can tell, this is done automatically and not with provided
scripts I can modify.
The create table statement comes prior to index creation.
It seems like the phrase "CHARACTER SET" isn't recognized and somehow should
be avoided when parsed.
Eliran Bivas
-- co-founder and editor of
Hello,
I am no expert but I think that creating multi-column indexes based on the
combination of columns that appear in the where clause could help
improve the performance of your queries.
e.g. (based on the SQL you provided)
CREATE INDEX IF NOT EXISTS comb_index_name
ON CURRENT_VA
Hi,
I am using in-memory h2 db and I have 8 tables. Each table has
15 to 20 columns. One table with 60 columns. I have two indexes per
table. Each table will have at most 3k rows.
Every 5 sec I am updating these tables with new data. I am
updating/inserting/deleting based on the de
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