Thanks Richard, that's much clearer.
Just one thing: "The page_size pragma will only set in the page size if ..."
The "in" looks out of place :)
-Rowan
On 12 September 2016 at 19:43, Richard Hipp wrote:
> On 9/12/16, Rowan Worth wrote:
> > The docs for PRAGMA page_size say that it is effecti
On 9/12/16, Rowan Worth wrote:
> The docs for PRAGMA page_size say that it is effective if issued "prior to
> the first CREATE statement".
Fixed at https://www.sqlite.org/draft/pragma.html#pragma_page_size
This will be pushed to the main website at the next release.
--
D. Richard Hipp
d...@sqli
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Rowan Worth
Gesendet: Montag, 12. September 2016 12:14
An: General Discussion of SQLite Database
Betreff: [sqlite] page_size: bug with PRAGMA or documentation?
Hey guys,
The docs for PRAGMA page_size say that it is effective
Hey guys,
The docs for PRAGMA page_size say that it is effective if issued "prior to
the first CREATE statement". So imagine my surprise when I found page_size
to be ineffective without ever issuing a CREATE statement!
The sequence goes like so:
$ rm /tmp/lol.db; sqlite3 /tmp/lol.db
SQLite versi
Ward WIllats wrote:
> sqlite> attach database '/tmp/RareData.db' as rd; < ATTACH SECOND DB
> sqlite> pragma page_size=512; <- SET MAIN DB PAGE SIZE
> ...
> sqlite> pragma journal_mode=WAL;
This sets the journal mode of _both_ databases to WAL.
This requires that both database f
On Tue, Aug 16, 2016 at 12:24 PM, Ward WIllats
wrote:
> Good thought. But no. In fact, I should have included the line where I
> deleted it before taking the trace below.
>
> ~# rm /tmp/RareData.db
> ~# /usr/local/bin/sqlite3 /opt/foundation/core_db.db
> SQLite version 3.10.1 2016-01-13 21:41:56
Good thought. But no. In fact, I should have included the line where I deleted
it before taking the trace below.
~# rm /tmp/RareData.db
~# /usr/local/bin/sqlite3 /opt/foundation/core_db.db
SQLite version 3.10.1 2016-01-13 21:41:56
> On Aug 16, 2016, at 11:17 AM, Scott Hess wrote:
>
> Is there
Is there any possibility that the attached db already existed before
you ran this? Because once a db exists (contains pages) the page size
is fixed until you run vacuum.
On Tue, Aug 16, 2016 at 10:53 AM, Ward WIllats wrote:
>
>>> On Aug 12, 2016, at 11:44 PM, Dan Kennedy wrote:
>>>
>>> On 08/13
>> On Aug 12, 2016, at 11:44 PM, Dan Kennedy wrote:
>>
>> On 08/13/2016 01:14 AM, Ward WIllats wrote:
>>
>> Can't reproduce this problem here. Are you able to reproduce it with the
>> shell tool?
>>
>
>
> Yes, if I use the shell on our embedded system (OpenWRT/Linux). I should have
> added
> On Aug 12, 2016, at 11:44 PM, Dan Kennedy wrote:
>
> On 08/13/2016 01:14 AM, Ward WIllats wrote:
>
> Can't reproduce this problem here. Are you able to reproduce it with the
> shell tool?
>
Yes, if I use the shell on our embedded system (OpenWRT/Linux). I should have
added that:
1. The
On 08/13/2016 01:14 AM, Ward WIllats wrote:
Consider:
1. Create a new database, set the pragma page_size=512
2. Create a new database on the connection with ATTACH DATABASE
'/tmp/number_two.db' AS second;
3. Issue pragma second.page_size=4096 to try and set the page size on the
attached DB
Consider:
1. Create a new database, set the pragma page_size=512
2. Create a new database on the connection with ATTACH DATABASE
'/tmp/number_two.db' AS second;
3. Issue pragma second.page_size=4096 to try and set the page size on the
attached DB to 4096.
4. Read back with pragma second.page
> Le 29 f?vr. 2016 ? 12:34, Simon Slavin a ?crit :
>
> On 29 Feb 2016, at 9:14am, Olivier Mascia wrote:
>
>> we have found the sweet spot (for us, and for now) to be 4K page sizes,
>> which just happen to be the virtual memory page size of Windows system
>
> Yes. That's the idea. Match the
hi,all
Could different page_size do impact on the speed of retrieving record?
Is page_size 8192 faster than page_size 1024 or page_szie 4096? or The
pagesize has nothing to do with the retrieving speed.
Best reagard!
Jim Wang.
On 29 Feb 2016, at 9:14am, Olivier Mascia wrote:
> we have found the sweet spot (for us, and for now) to be 4K page sizes, which
> just happen to be the virtual memory page size of Windows system
Yes. That's the idea. Match the page size of the database to the size of the
chunks your operat
> Le 29 f?vr. 2016 ? 09:22, Jim Wang <2004wqg2008 at 163.com> a ?crit :
>
> hi,all
>
> Could different page_size do impact on the speed of retrieving record?
> Is page_size 8192 faster than page_size 1024 or page_szie 4096? or The
> pagesize has nothing to do with the retrieving speed.
.
> -Original Message-
> From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-
> bounces at mailinglists.sqlite.org] On Behalf Of Olivier Mascia
> Sent: Monday, 29 February, 2016 02:15
> To: SQLite mailing list
> Subject: Re: [sqlite] Page_size
>
&g
ers-
> > bounces at mailinglists.sqlite.org] On Behalf Of Olivier Mascia
> > Sent: Monday, 29 February, 2016 02:15
> > To: SQLite mailing list
> > Subject: Re: [sqlite] Page_size
> >
> >
> > > Le 29 f?vr. 2016 ? 09:22, Jim Wang <2004wqg2008 at 163.com>
nd no
other indices; and a transfer thread that copies the entries over into the
"real" table in a batch transaction.
-Ursprüngliche Nachricht-
Von: Andy (KU7T) [mailto:k...@ku7t.org]
Gesendet: Montag, 19. Jänner 2015 09:06
An: sqlite-users@sqlite.org
Betreff: [sqlite] Page_
Hi,
I am using System.Data.SQLite, Version=1.0.92.0. I read that increasing the
page_size to 4k on modern OS is a good thing and should speed things up.
However, I have a particular query that takes substantially longer. I tried
to make sure that nothing else is changed, so I am a little puzzle
ah - good to know. that is what i was looking for.
thanks
tom
On Apr 25, 2010, at 10:21 PM, Dan Kennedy wrote:
> The page formats use 16-bit unsigned integers to store various offsets
> (in bytes) to cells and free-blocks within a page. So it definitely
> won't work with greater than 64KB pages
On Apr 26, 2010, at 11:09 AM, Tom Broadbent wrote:
>
> thanks for the replies.
>
> understood. i was informed that our underlying (EMMC??) FS will do
> this w/ FS pages, i.e. read the entire 256k FS page, modify some
> small portion of it, and write it out again. i'm higher in the
> stack
thanks for the replies.
understood. i was informed that our underlying (EMMC??) FS will do this w/ FS
pages, i.e. read the entire 256k FS page, modify some small portion of it, and
write it out again. i'm higher in the stack so i don't understand the
underlying FS mechanisms; i've simply ask
On Apr 21, 2010, at 4:37 PM, Pavel Ivanov wrote:
> I don't know anything about internal support of pages bigger than 32k.
> But I want to warn you: each table and each index in SQLite occupy at
> least 1 database page. So let's say you have 4 tables with 1
> additional index each (besides 'intege
I don't know anything about internal support of pages bigger than 32k.
But I want to warn you: each table and each index in SQLite occupy at
least 1 database page. So let's say you have 4 tables with 1
additional index each (besides 'integer primary key' one). With 256k
pages this schema will resul
i've read in the docs that SQLITE_MAX_PAGE_SIZE can't be > 32k (below). is
this limitation still valid?
we have an embedded FS that is _very_ slow and performs best w/ a write page
size of 256k. will bad things happen if i configure SQLite w/ 256k pages?
thanks
tom
Maximum Database Page Size
[EMAIL PROTECTED] wrote:
Martin Pelletier <[EMAIL PROTECTED]> wrote:
Hello,
I am trying to optimise an SQLite database running on Windows. One of
the things I'm looking at is page size. However, a page on sqlite.org
(http://www.sqlite.org/cvstrac/wiki?p=PerformanceTuningWindows) mentions
Martin Pelletier <[EMAIL PROTECTED]> wrote:
>
> On a side note, that comment on the page
> (http://www.sqlite.org/cvstrac/wiki?p=PerformanceTuningWindows) should
> really be clarified to reflect what you just told me. It is clearly told
> that the page_size cannot be changed, but the bit about
Martin Pelletier <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I am trying to optimise an SQLite database running on Windows. One of
> the things I'm looking at is page size. However, a page on sqlite.org
> (http://www.sqlite.org/cvstrac/wiki?p=PerformanceTuningWindows) mentions
> this:
>
> "Just a
Hello,
I am trying to optimise an SQLite database running on Windows. One of
the things I'm looking at is page size. However, a page on sqlite.org
(http://www.sqlite.org/cvstrac/wiki?p=PerformanceTuningWindows) mentions
this:
"Just a note that you must also perform this command [PRAGMA
page
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