Sent: Friday, February 27, 2009 8:48 PM
To: Derby Discussion
Subject: Re: inserts slowing down after 2.5m rows
I've increased the log size and the checkpoint interval, but
it doesn't seem to help.
It looks like the inserts begin to dramatically slow down once the
table reaches the initial allocation of pages. Things just fly along until it
gets to about 1100 pages (I've allocated an initial 1000 pages, pages are 32k).
Any suggestions on how to keep the inserts moving quickly at this
On Fri, Feb 27, 2009 at 3:41 PM, email@example.com
The application is running on a client machine. I'm not sure
how to tell if there's a different disk available that I could log to.
If checkpoint is causing this delay, how to a manage that? Can I
turn checkpointing off? I already have durability set to test; I'm not
concerned about recovering from a crashed db.
On Fri, Feb 27, 2009 at 9:34 AM, Peter Ondruška wrote:
> Could be checkpoint.. BTW to speed up bulk load you may want
large log files located separately from data disks.
2009/2/27, Brian Peterson < firstname.lastname@example.org >:
> I have a big table that gets a lot of inserts. Rows are
inserted 10k at a
> time with a table function. At around 2.5 million rows,
inserts slow down
> from 2-7s to around 15-20s. The table's dat file is around
> I have durability set to "test", table-level locks,
a primary key index and
> another 2-column index on the table. Page size is at the max
and page cache
> set to 4500 pages. The table gets compressed (inplace) every
> I'm using Derby 10.4 with JDK 1.6.0_07, running on Windows
XP. I've ruled
> out anything from the rest of the application, including GC
> follows a consistent pattern during the whole load). It is a
> system. The database has a fixed number of tables (so there's
a fixed number
> of dat files in the database directory the whole time). The
logs are getting
> cleaned up, so there's only a few dat files in the log
directory as well.
> Any ideas what might be causing the big slowdown after so