>* In SQLite, my blobs won't be corrupted if the machine loses power
> the way they (probably) will be if I write my own code to access
> the file-system.
But, in case of a corruption, you will have entire blob DB corrupted versus
at least one file (aka one row in DB) corrupted.
-
>>I'm fairly sure disk space requirements will be nearly identical in
>>each case...
In case of blobs in SQLite there will be less disk space used than in
case of file system (cluster size etc.)
-
To unsubscribe, send e
[EMAIL PROTECTED] wrote:
Guess you can't please everybody :-) Right now we have some
documentation in the source tree and some on the wiki, which
I suppose is guaranteed to please nobody.
So make the wiki available for download. ;)
Martin
-
> I'm quite interested in hearing people's reasoning for going the blob route,
> when you have a perfectly good "database" format for "blobs" already (various
> filesystems).
Three technical reasons for me personally:
* Can include blob operations as part of atomic transactions.
* In SQLite
On 2/22/07, Rich Shepard <[EMAIL PROTECTED]> wrote:
However, I'm stuck on the proper SQL syntax. A nudge in the right
direction -- including pointers to the appropriate documentation -- would be
much appreciated.
The "rule of thumb" is that anything that appears in the group-by
clause can app
Rich Shepard <[EMAIL PROTECTED]> wrote:
I have a table, 'voting,' with 31 columns. For each of 28 REAL
columns I need to calculate averages both by groups and total. I
tried:
sqlite> select AVG(pos) from voting where cat = 'eco';
and 0.0 was returned.
The query looks good. What's the data in
I have a table, 'voting,' with 31 columns. For each of 28 REAL columns I
need to calculate averages both by groups and total. I tried:
sqlite> select AVG(pos) from voting where cat = 'eco';
and 0.0 was returned. Before this I tried combinations that were
syntactically incorrect; e.g.,
sqlite>
--- "Shan, Zhe (Jay)" <[EMAIL PROTECTED]> wrote:
> If to use SQLite to create a database in Linux, the database file will
> be granted permission 644 as default.
> Is this value hardcoded in the current version? Is it possible to
> change this default vaule, say to 664 or something else?
man umask
This is not actually about SQLite. man umask
M. Manese
On 2/22/07, Shan, Zhe (Jay) <[EMAIL PROTECTED]> wrote:
Hi,
If to use SQLite to create a database in Linux, the database file will
be granted permission 644 as default.
Is this value hardcoded in the current version? Is it possible to
chang
Hi,
If to use SQLite to create a database in Linux, the database file will
be granted permission 644 as default.
Is this value hardcoded in the current version? Is it possible to
change this default vaule, say to 664 or something else?
Thanks.
Jay
On February 21, 2007, [EMAIL PROTECTED] wrote:
> "Brett Keating" <[EMAIL PROTECTED]> wrote:
> > Hi,
> >
> > I'm curious about what the effect of having a blob in the database may
> > be on performance. I have two design options: 1) put a small image file
> > (15-30kbyte) into the database as a blob
[EMAIL PROTECTED] wrote:
Sure you can. You just have to put the expression in parentheses
(to avoid a parsing conflict). Try this:
CREATE TABLE test1(
date TEXT DEFAULT (strftime('%Y-%m-%d %H:%M:%f', 'now')),
dummy int
);
INSERT INTO test1(dummy) VALUES(1);
SELECT
Thanks I think this answers my question well!
Brett
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 21, 2007 1:41 PM
To: sqlite-users@sqlite.org
Subject: Re: [sqlite] Effect of blobs on performance
"Brett Keating" <[EMAIL PROTECTED]> wrote
Thanks for the quick reply.
I was lysdexic, I meant to say 20 columns. Probably would never exceed
20,000 rows, most likely would hover around 2-4K rows in a typical
situation.
If it has no effect on performance, I'd rather hold it in the database
because I do like the idea of having a "neat pa
My suggestion: Do a quick experiment. I had a similar question a year
or so ago. I wrote some code a year or so that generated random blobs
of varying sizes and tossed them into a SQLite DB and onto files on
the file system (Mac OS).
There are some complicating variables, such as our applic
"Brett Keating" <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I'm curious about what the effect of having a blob in the database may
> be on performance. I have two design options: 1) put a small image file
> (15-30kbyte) into the database as a blob, and 2) store the image in a
> separate file on disk and
On 2/21/07, Brett Keating <[EMAIL PROTECTED]> wrote:
Hi,
I'm curious about what the effect of having a blob in the database may
be on performance. I have two design options: 1) put a small image file
(15-30kbyte) into the database as a blob, and 2) store the image in a
separate file on disk and
Hi,
I'm curious about what the effect of having a blob in the database may
be on performance. I have two design options: 1) put a small image file
(15-30kbyte) into the database as a blob, and 2) store the image in a
separate file on disk and hold the filename in the database. My table
has around
On 2/21/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
"P Kishor" <[EMAIL PROTECTED]> wrote:
>
> is it possible to add usage such as the above, and many, many
> wonderful SQL suggestions routinely provided by Igor Tandetnik (thanks
> Igor!) to the syntax docs in the form of user-submitted comme
"P Kishor" <[EMAIL PROTECTED]> wrote:
>
> is it possible to add usage such as the above, and many, many
> wonderful SQL suggestions routinely provided by Igor Tandetnik (thanks
> Igor!) to the syntax docs in the form of user-submitted comments?
>
I was trying to move all of the documentation int
On 2/21/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
Dennis Cote <[EMAIL PROTECTED]> wrote:
>
> The problem is that you can't use a function like strftime as the
> default value for a column when you create a tbale. It only accepts
> NULL, a string constant, a number, or one of the magic curr
Dennis Cote <[EMAIL PROTECTED]> wrote:
>
> The problem is that you can't use a function like strftime as the
> default value for a column when you create a tbale. It only accepts
> NULL, a string constant, a number, or one of the magic current_* values.
>
Sure you can. You just have to put th
[EMAIL PROTECTED] wrote:
This isn't a bug.
The magic current_timestamp keyword is really an alias for
"datetime('now')". And datetime('now') returns you a text
string in the format "YY-MM-DD HH:MM:SS". Yes, this means
that the seconds have been rounded to the nearest whole
second. But that
On Wed, 21 Feb 2007, Igor Tandetnik wrote:
Yes, that's what GROUP BY does. One representative for each group.
Igor,
A-ha! It has been a long time for me.
select * from voting order by cat, pos;
Thank you very much. Makes sense now.
Rich
--
Richard B. Shepard, Ph.D. |
Rich Shepard <[EMAIL PROTECTED]> wrote:
The table has 180 rows and 31 columns. What I need to do is extract
the records and group them by two columns (one as a sub-group of the
other). However, even one 'group by' retrieves only three records,
the last one for each group:
Yes, that's what GRO
It has been a long time since I've written SQL, and this may explain why a
select is not returning what I expect.
The table has 180 rows and 31 columns. What I need to do is extract the
records and group them by two columns (one as a sub-group of the other).
However, even one 'group by' retri
Doug Currie wrote:
Thanks for the links.
I repeated Joe's test on my XP box and plotted the results - it appears
that the time is adjusted by up to +/- 800us every 12/64ths of a second
and interpolated between. Interesting stuff, though I'm not convinced
that hectonanoseconds will catch on. :
Alexey Tourbin <[EMAIL PROTECTED]> wrote:
> Hello,
>
> All tests pass on i386 but the following test fails on x86_64:
>
> types3-1.3...
> Expected: [wideInt integer]
> Got: [int integer]
This is a failure in the test harness, not in SQLite itself.
This is nothing to worry about.
--
D. Richa
Dennis Cote <[EMAIL PROTECTED]> wrote:
>
> sqlite> select strftime('%f', 'now');
> 0.622
> sqlite> select strftime('%f', current_timestamp);
> 34.000
>
> You might want to file a bug report about this.
>
This isn't a bug.
The magic current_timestamp keyword is really an alias
Hello,
All tests pass on i386 but the following test fails on x86_64:
types3-1.3...
Expected: [wideInt integer]
Got: [int integer]
pgpOit3QhrHc1.pgp
Description: PGP signature
On Wednesday, February 21, 2007 Martin Jenkins wrote:
> Joe Wilson wrote:
>> So this machine's minimum timer resolution is 0.0155 seconds,
>> or 15.5 milliseconds.
> XP box?
> XP & timers: http://www.lochan.org/2005/keith-cl/useful/win32time.html
Also see the comments about timeBeginPeriod()
Tom Olson wrote:
Thank you for the reply. I ran the select statement you sent me as well as
testing it with 'now' and both do indeed show the fractional seconds,
however if I use current_timestamp I do not see the fractional seconds.
using 'now' should suffice as a workaround. Curious though?
Dr. H,
Thank you for the reply. I ran the select statement you sent me as well as
testing it with 'now' and both do indeed show the fractional seconds,
however if I use current_timestamp I do not see the fractional seconds.
using 'now' should suffice as a workaround. Curious though?
Kind Rega
Rich Shepard wrote:
>
> On Sun, 18 Feb 2007, fangles wrote:
>
>> Thank you Igor, that's fantastic. I'm reading lots of SqLite tutorials
>> but
>> a lot of the SQL is so far out of my brain's reach that it doesn't make
>> sense to me. And I love to play:):):)
>
>Look at Joe Celko's books o
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