RE: inserts slowing down after 2.5m rows

[derby]

> Another question is why the maximum is set to 1000 pages.
> Any takers?

Because it was a big nice round number?

And when I say big, I meant it as it was big enough at the time.

Remember that Cloudscape was designed to fill a niche. It was designed to be
a small, embeddable engine that was 100% Java.

It was not meant as a competitor to the General Purpose RDBMs engines.

This is why I've asked that those pushing the Cloudscape development to
consider what they want this engine to be. Adding more features creates a
larger footprint which has a negative impact on some users who want to embed
the engine in a small downloadable app. 

This is why I recommended that those behind Derby consider building a more
modular approach to the engine. Sort of a plug and play for deployment of
features. (An example, if you're going to use the engine in an embeddable
format, you don't load up a container class that has chunks, page spaces,
table spaces, etc. You don't allow containers that utilize raw disks. You
don't do portioning. However if someone is going to use this in a more
traditional role, you do create the engine and load those classes.)

HTH

-Mike

> -Original Message-
> From: kristian.waa...@sun.com [mailto:kristian.waa...@sun.com]
> Sent: Tuesday, March 03, 2009 6:19 AM
> To: Derby Discussion
> Subject: Re: inserts slowing down after 2.5m rows
> 
> Brian Peterson wrote:
> > I thought I read in the documentation that 1000 was the max initial
> > pages you could allocate, and after that, Derby allocates a page at a
> > time. Is there some other setting for getting it to allocate more at a
> time?
> 
> Another question is why the maximum is set to 1000 pages.
> Any takers?
> 
> If the property can be set higher and controlled on a per conglomerate
> (table or index) basis, it can be a nice tool for those who require or
> want to use such tuning.
> 
> 
> --
> Kristian
> 
> >
> >
> >
> > Brian
> >
> >
> >
> > *From:* Michael Segel [mailto:mse...@segel.com] *On Behalf Of
> > *de...@segel.com
> > *Sent:* Friday, February 27, 2009 9:59 PM
> > *To:* 'Derby Discussion'
> > *Subject:* RE: inserts slowing down after 2.5m rows
> >
> >
> >
> > Ok,
> >
> >
> >
> > For testing, if you allocate 2000 pages, then if my thinking is ok, then
> > you'll fly along until you get until 2100 pages.
> >
> >
> >
> > It sounds like you're hitting a bit of a snag where after your initial
> > allocation of pages, Derby is only allocating a smaller number of pages
> > at a time.
> >
> >
> >
> > I would hope that you could configure the number of pages to be
> > allocated in blocks as the table grows.
> >
> >
> >
> >
> >
> > 
> >
> > *From:* publicay...@verizon.net [mailto:publicay...@verizon.net]
> > *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 point?
> >
> >
> >
> > Brian
> >
> >
> >
> > On Fri, Feb 27, 2009 at  3:41 PM, publicay...@verizon.net wrote:
> >
> >
> >
> >  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.
> >
> >
> >
> > Brian
> >
> >
> >
> > On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote:
> >
> >
> >
> >>  Could be checkpoint.. BTW to speed up bulk load you may want to use
> >
> > large log files located separately from data disks.
> >
> >
> >
> > 2009/2/27, Brian Peterson < dianeay...@verizon.net
> > <mailto:dianeay...@verizon.net>>:
> >
> >>  I have a big table th

Re: inserts slowing down after 2.5m rows

[Kristian Waagan]

Brian Peterson wrote:
I thought I read in the documentation that 1000 was the max initial 
pages you could allocate, and after that, Derby allocates a page at a 
time. Is there some other setting for getting it to allocate more at a time?


Another question is why the maximum is set to 1000 pages.
Any takers?

If the property can be set higher and controlled on a per conglomerate 
(table or index) basis, it can be a nice tool for those who require or 
want to use such tuning.



--
Kristian



 


Brian

 

*From:* Michael Segel [mailto:mse...@segel.com] *On Behalf Of 
*de...@segel.com

*Sent:* Friday, February 27, 2009 9:59 PM
*To:* 'Derby Discussion'
*Subject:* RE: inserts slowing down after 2.5m rows

 


Ok,

 

For testing, if you allocate 2000 pages, then if my thinking is ok, then 
you'll fly along until you get until 2100 pages.


 

It sounds like you're hitting a bit of a snag where after your initial 
allocation of pages, Derby is only allocating a smaller number of pages 
at a time.


 

I would hope that you could configure the number of pages to be 
allocated in blocks as the table grows.


 

 




*From:* publicay...@verizon.net [mailto:publicay...@verizon.net]
*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 point?

 


Brian

 


On Fri, Feb 27, 2009 at  3:41 PM, publicay...@verizon.net wrote:

 

 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.


 


Brian

 


On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote:

 


 Could be checkpoint.. BTW to speed up bulk load you may want to use


large log files located separately from data disks.

 

2009/2/27, Brian Peterson < dianeay...@verizon.net  
<mailto:dianeay...@verizon.net>>:



 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 800-900M.














 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 500,000 

rows.


 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 (memory usage



 follows a consistent pattern during the whole load). It is a local file


 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 many loads?















 Brian

RE: inserts slowing down after 2.5m rows

[Brian Peterson]

I thought I read in the documentation that 1000 was the max initial pages
you could allocate, and after that, Derby allocates a page at a time. Is
there some other setting for getting it to allocate more at a time?

 

Brian

 

From: Michael Segel [mailto:mse...@segel.com] On Behalf Of de...@segel.com
Sent: Friday, February 27, 2009 9:59 PM
To: 'Derby Discussion'
Subject: RE: inserts slowing down after 2.5m rows

 

Ok, 

 

For testing, if you allocate 2000 pages, then if my thinking is ok, then
you'll fly along until you get until 2100 pages.

 

It sounds like you're hitting a bit of a snag where after your initial
allocation of pages, Derby is only allocating a smaller number of pages at a
time.

 

I would hope that you could configure the number of pages to be allocated in
blocks as the table grows.

 

 

  _  

From: publicay...@verizon.net [mailto:publicay...@verizon.net] 
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 point?

 

Brian

 

On Fri, Feb 27, 2009 at  3:41 PM, publicay...@verizon.net wrote:

 

 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. 

 

Brian 

 

On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote: 

 

> Could be checkpoint.. BTW to speed up bulk load you may want to use 

large log files located separately from data disks. 

 

2009/2/27, Brian Peterson < dianeay...@verizon.net >: 

> 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 800-900M. 

> 

> 

> 

> 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 500,000 rows.


> 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 (memory usage 

> follows a consistent pattern during the whole load). It is a local file 

> 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 many loads? 

> 

> 

> 

> Brian 

> 

> 

> 

> 

RE: inserts slowing down after 2.5m rows

[derby]

Ok, 

 

For testing, if you allocate 2000 pages, then if my thinking is ok, then
you'll fly along until you get until 2100 pages.

 

It sounds like you're hitting a bit of a snag where after your initial
allocation of pages, Derby is only allocating a smaller number of pages at a
time.

 

I would hope that you could configure the number of pages to be allocated in
blocks as the table grows.

 

 

  _  

From: publicay...@verizon.net [mailto:publicay...@verizon.net] 
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 point?

 

Brian





On Fri, Feb 27, 2009 at  3:41 PM, publicay...@verizon.net wrote:

 

 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. 

 

Brian 





On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote: 

 

> Could be checkpoint.. BTW to speed up bulk load you may want to use 

large log files located separately from data disks. 

 

2009/2/27, Brian Peterson < dianeay...@verizon.net >: 

> 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 800-900M. 

> 

> 

> 

> 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 500,000 rows.


> 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 (memory usage 

> follows a consistent pattern during the whole load). It is a local file 

> 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 many loads? 

> 

> 

> 

> Brian 

> 

> 

> 

> 

Re: inserts slowing down after 2.5m rows

[publicayers]

 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 point?

Brian

On Fri, Feb 27, 2009 at  3:41 PM, publicay...@verizon.net wrote:

 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.


Brian

On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote:


Could be checkpoint.. BTW to speed up bulk load you may want to use

large log files located separately from data disks.

2009/2/27, Brian Peterson < dianeay...@verizon.net  
 >:
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 
800-900M.



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 500,000 rows. 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 (memory usage follows a consistent pattern during the 
whole load). It is a local file 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 many loads?


Brian

Re: inserts slowing down after 2.5m rows

[publicayers]

 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.


Brian

On Fri, Feb 27, 2009 at  9:34 AM, Peter Ondruška wrote:


Could be checkpoint.. BTW to speed up bulk load you may want to use

large log files located separately from data disks.

2009/2/27, Brian Peterson     >:
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 800-900M.



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 500,000 
rows.
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 (memory 
usage
follows a consistent pattern during the whole load). It is a local 
file
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 many loads?



Brian

Re: inserts slowing down after 2.5m rows

[Peter Ondruška]

Could be checkpoint.. BTW to speed up bulk load you may want to use
large log files located separately from data disks.

2009/2/27, Brian Peterson :
> 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 800-900M.
>
>
>
> 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 500,000 rows.
> 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 (memory usage
> follows a consistent pattern during the whole load). It is a local file
> 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 many loads?
>
>
>
> Brian
>
>
>
>

inserts slowing down after 2.5m rows

[Brian Peterson]

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 800-900M.

 

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 500,000 rows.
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 (memory usage
follows a consistent pattern during the whole load). It is a local file
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 many loads?

 

Brian