Hi,

yes I use a macbook pro:
version 10.6.2
processor 2.66 GHz Intel Core 2 Duo
Memory 4 GB 1067 MHz DDR3

the SSD is:

*APPLE SSD TS256:*


  Capacity: 251 GB (251,000,193,024 bytes)

  Model: APPLE SSD TS256

  Revision: W010011b

  Serial Number:         039920002048

  Native Command Queuing: No

  Removable Media: No

  Detachable Drive: No

  BSD Name: disk0

  Partition Map Type: GPT (GUID Partition Table)

  S.M.A.R.T. status: Verified

  Volumes:

*Macintosh HD:*

  Capacity: 250.66 GB (250,656,219,136 bytes)

  Available: 75.72 GB (75,723,247,616 bytes)

  Writable: Yes

  File System: Journaled HFS+

  BSD Name: disk0s2

  Mount Point: /

and below the results after running the recover tool:

---- Transaction log ----------
---- Statistics ----------
-- page count: 118363 empty: 36031 free: 36031
-- page data head: 2120454 empty: 61714802 rows: 60889992
-- page count type: 0 30% count: 36031
-- page count type: 1 51% count: 60901
-- page count type: 2 0% count: 319
-- page count type: 4 17% count: 20226
-- page count type: 5 0% count: 875
-- page count type: 6 0% count: 8

I opened the db with the shell tool, (it takes 6 seconds)
after closing I have this difference:
-rw-r--r--   1 sylvain  staff  242393088 Dec 21 10:55 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

I reopened it with the shell tool, (now it takes 1-2 second)
-rw-r--r--   1 sylvain  staff  224851968 Dec 21 10:57 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

again ... (it takes 1-2 second)
-rw-r--r--   1 sylvain  staff  217847808 Dec 21 10:58 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

again... (seems a bit faster to open, largely faster to close)
-rw-r--r--   1 sylvain  staff  213497856 Dec 21 10:59 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

again..
-rw-r--r--   1 sylvain  staff  210814976 Dec 21 11:00 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

again...
-rw-r--r--   1 sylvain  staff  206358528 Dec 21 11:01 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

now I run the shutdown compact command:
-rw-r--r--   1 sylvain  staff  168611840 Dec 21 11:01 wasdb.h2.db
-rw-r--r--   1 sylvain  staff  242407424 Dec 18 10:07 wasdb.h2.db original

after the shutdown compact command,
the db is very fast to open and to close... (1 second at most)

Please let me know if I can do anything else....

Best regards,
Sylvain








On Sun, Dec 20, 2009 at 1:54 PM, Thomas Mueller <
[email protected]> wrote:

> Hi,
>
> You wrote you use a SSD HD, what kind? What operating system and file
> system do you use (it looks like Mac OS, just to be sure)?
>
> According to the stack trace, most of the time (80%) is spent
> _closing_ the database file. That's really strange. Probably it is
> related to the SSD.
>
> Another 15% is spent writing empty pages. I wonder how many empty
> pages are in your database... In theory, it should be 0 if closed
> normally (unless you have deleted of lot of data before closing the
> database). Could you send me the database, or run the Recover tool and
> send me the last few lines of the .h2.sql file? To run the tool, start
> the H2 Console, then go to Tools - Recover. I'm mainly interested in
> the 'Statistics' part. For a small database, it is:
>
> ---- Transaction log ----------
> ---- Statistics ----------
> -- page count: 3890 empty: 0 free: 0
> -- page data head: 646148 empty: 4333817 rows: 2722563
> -- page count type: 1 96% count: 3761
> -- page count type: 2 0% count: 32
> -- page count type: 4 2% count: 88
> -- page count type: 5 0% count: 5
> -- page count type: 6 0% count: 1
>
> When you open and then close the database, does the database file size
> shrink? If yes, how much, and could you repeat opening / closing until
> it doesn't shink; or run the statement SHUTDOWN COMPACT.
>
> Regards,
> Thomas
>
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