Gary Scott wrote:
Hi, CVF initially. I will likely transition to IVF once a suitable version is
released.
Well, that should be easy enough - MSVC/CVF is the platform I used to
develop the interface.
I managed to extend the documentation on the interface last night - see
Hi
I've found SQLite faster than MySQL and Postgres for small/medium
databases. Now I have big ones and I really do not want to change, but
I have some performance issues.
Consider the following database schema:
CREATE TABLE tetragrams (word1 INTEGER, word2 INTEGER, word3 INTEGER,
word4
On Tue, 2007-04-17 at 11:53 +0100, Alberto Simões wrote:
> Hi
>
> I've found SQLite faster than MySQL and Postgres for small/medium
> databases. Now I have big ones and I really do not want to change, but
> I have some performance issues.
>
> Consider the following database schema:
> CREATE
Marco Bambini wrote:
This query on a small database sometimes takes more than 40 seconds:
select _rowid, public_id, vote_count, status, summary, component,
date(date_modified), quickfix from reports where public = 1 AND _rowid
IN (select distinct r._rowid from reports r, segments s where
On 4/17/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
"=?ISO-8859-1?Q?Alberto_Sim=F5es?=" <[EMAIL PROTECTED]> wrote:
>
> Consider the following database schema:
> CREATE TABLE tetragrams (word1 INTEGER, word2 INTEGER, word3 INTEGER,
> word4 INTEGER, occs INTEGER, PRIMARY KEY (word1, word2,
Hi
I would like to know if the order I get the rows from a select
(without ORDER BY) is the order by which the values were inserted.
I know this is the behavior for MySQL, but not sure about SQLite.
THank you
Alberto
--
Alberto Simões
Additionally, note that if you use ORDER BY, and it _is_ in the
indicated order already, then sqlite will optimize the ORDER BY away
entirely. So use ORDER BY.
-scott
On 4/17/07, Andrew Finkenstadt <[EMAIL PROTECTED]> wrote:
The order of the rows returned by a select that does not have an
We got bit by this when moving from MSSQL 2000 to MSSQL 2005. MSSQL
returned rows by default in PK order and one of our former developers
depended on this so when the behavior changed in MSSQL 2005 (which is fine
'cause it wasn't documented or expected behavior) our app broke in
unexpected ways.
> I know this is the behavior for MySQL, but not sure about SQLite.
I'v heard about some version of mysql that didn't return rows in the same
order (but haven't seen it myselt). So unless this behaviour is documented
in mysql manual, it's not a good idea to rely on this. Actually I'v seen
This is news to me. Why can't SQlite use more than one index?
Samuel R. Neff wrote:
afaik SQLite will only use one index per table
--
Martin Pelletier
Informatique / Software Development
Infodev Electronic Designers International Inc.
Tel : +1 (418) 681-3539, poste /ext. 114
Fax : +1 (418)
At 16:46 17/04/2007, you wrote:
This is news to me. Why can't SQlite use more than one index?
Possibly because it's 'SQ *Lite*'?
The query optimiser in SQLite is a lot less powerful than in some
other SQL databases - but then it's a fraction of the size as well...
Instead of having two
At 16:45 17/04/2007, Stef Mientki wrote:
I don't understand this behaviour,
is this too complex ?
or am I doing something wrong ?
I use the following syntax, and I get 7 records back,
(which is not correct in my opinion)
SELECT PO.* FROM Koppel
LEFT JOIN PO
WHERE (Koppel.K_App == PO.App)
I don't understand this behaviour,
is this too complex ?
or am I doing something wrong ?
I use the following syntax, and I get 7 records back,
(which is not correct in my opinion)
SELECT PO.* FROM Koppel
LEFT JOIN PO
WHERE (Koppel.K_App == PO.App)
AND (Koppel.K_naam == 'MVE')
Stef Mientki <[EMAIL PROTECTED]> wrote:
I use the following syntax, and I get 7 records back,
(which is not correct in my opinion)
SELECT PO.* FROM Koppel
LEFT JOIN PO
WHERE (Koppel.K_App == PO.App)
AND (Koppel.K_naam == 'MVE')
AND (PO.ALL_answered == '0')
If I leave the
Martin Pelletier <[EMAIL PROTECTED]> wrote:
> This is news to me. Why can't SQlite use more than one index?
>
It can. You just have to tell it to explicitly by restructuring
your SQL.
As an example, consider this query:
SELECT * FROM table1 WHERE a=5 AND b=11;
Suppose there are two
The order of the rows returned by a select that does not have an ORDER BY
clause is guaranteed by the standard to be in any arbitrary order, even from
one execution to another due to changes in the underlying data, index
statistics, amount of memory available, or even the phase of the moon.
Use
This query on a small database sometimes takes more than 40 seconds:
select _rowid, public_id, vote_count, status, summary, component, date
(date_modified), quickfix from reports where public = 1 AND _rowid IN
(select distinct r._rowid from reports r, segments s where
s.report_id = r._rowid
afaik SQLite will only use one index per table so if you have a where clause
"WHERE public = 1 and _rowid IN (...)" it will use an index on public and
not _rowid. Swapping the where clause around should have a significant
impact:
select
_rowid,
public_id,
vote_count,
Interesting and thanks for that tip.
Is there a performance penalty from structuring the
query like that? I take it that there will be.
RBS
> Martin Pelletier <[EMAIL PROTECTED]> wrote:
>> This is news to me. Why can't SQlite use more than one index?
>>
>
> It can. You just have to tell it to
"=?ISO-8859-1?Q?Alberto_Sim=F5es?=" <[EMAIL PROTECTED]> wrote:
>
> Consider the following database schema:
> CREATE TABLE tetragrams (word1 INTEGER, word2 INTEGER, word3 INTEGER,
> word4 INTEGER, occs INTEGER, PRIMARY KEY (word1, word2, word3,
> word4));
> CREATE INDEX tet_b ON tetragrams
The saga continues...
I was very excited by the idea that there was something wrong with the CF
Card. The theory fits all the facts: it explains why the original database
threw unspecified errors, it explains why now SQLite is throwing errors, it
explains why I can't reproduce the problem in
Hi, when I read the article about sqlite and multithread in cvstrac, I
understood that I need to compile my source files using sqlite functions
with -DTHREADSAFE=1.
Now, due to a pproblem I had in my project I re-readad this article and
began to think I should compile sqlite source files using
What is the guy on in the field doing that you are not? Are you using his
device for the testing?
Since it takes minutes for him to encounter the error it can't be that hard
to recreate. Follow him around for an hour or so and see how he uses the
program. It could easily be something he's doing
Ok, I'll use ORDER BY.
Thanks!
Alberto
On 4/17/07, Samuel R. Neff <[EMAIL PROTECTED]> wrote:
We got bit by this when moving from MSSQL 2000 to MSSQL 2005. MSSQL
returned rows by default in PK order and one of our former developers
depended on this so when the behavior changed in MSSQL 2005
I don't know if this is the problem, but, for some reason you're
mixing C/C++ syntax in with SQL there.
You don't use '==', you should just use '='
You don't use '!=', you should use '<>'
thanks Paul,
but although I can never find this information when I need it :-(
AFAIK, both
Igor Tandetnik wrote:
Stef Mientki <[EMAIL PROTECTED]> wrote:
I use the following syntax, and I get 7 records back,
(which is not correct in my opinion)
SELECT PO.* FROM Koppel
LEFT JOIN PO
WHERE (Koppel.K_App == PO.App)
AND (Koppel.K_naam == 'MVE')
AND (PO.ALL_answered
Perhaps you need to design an experiment to detect the problem. Part of
it might be to log activity. Relying on a debugger rather than logical
analysis can waste a lot of time.
Joel Cochran wrote:
I've had him sit beside my in my office and attempt to recreate it, both
using his device and
It looks like short_column_names pragma is ignored when GROUP BY is used in
a query. Is this considered expected behavior? I hope not.. :-)
Thanks,
Sam
sqlite> pragma short_column_names;
short_column_names
--
1
sqlite> pragma full_column_names;
full_column_names
Either add a trace-log which shows the flow of the program (entering,
exiting methods, database commands accessed).
It's not so simple that when you send the program to him in the field, it's
a release build and when you test you are using a debug build?
On 4/17/07, Joel Cochran <[EMAIL
Unfortunately DEBUG builds change timing entirely on windows platforms. I
would suggest creating a release build with symbols.
Mike
-Ursprüngliche Nachricht-
Von: Joel Cochran [mailto:[EMAIL PROTECTED]
Gesendet: Dienstag, 17. April 2007 20:59
An: sqlite-users@sqlite.org
Betreff: Re:
Stef Mientki wrote:
I don't know if this is the problem, but, for some reason you're
mixing C/C++ syntax in with SQL there.
You don't use '==', you should just use '='
You don't use '!=', you should use '<>'
thanks Paul,
but although I can never find this information when I need it :-(
configure --enable-threadsafe should do it.
Rafi Cohen <[EMAIL PROTECTED]> wrote: Hi, when I read the article about sqlite
and multithread in cvstrac, I
understood that I need to compile my source files using sqlite functions
with -DTHREADSAFE=1.
Now, due to a pproblem I had in my project I
Dennis Cote wrote:
Stef Mientki wrote:
I don't know if this is the problem, but, for some reason you're
mixing C/C++ syntax in with SQL there.
You don't use '==', you should just use '='
You don't use '!=', you should use '<>'
thanks Paul,
but although I can never find this
Stef Mientki wrote:
But it doesn't solve my problem :-(
I've the feeling that despite the suggestions of Igor,
the problem still exists, caused by the zero values ??
I'll try tomorrow again with some other values.
Stef,
Oh... I though Igor had solved your problem so I didn't give it much
Dennis Cote wrote:
Stef Mientki wrote:
But it doesn't solve my problem :-(
I've the feeling that despite the suggestions of Igor,
the problem still exists, caused by the zero values ??
I'll try tomorrow again with some other values.
Stef,
Oh... I though Igor had solved your problem so I
Dennis Cote <[EMAIL PROTECTED]> wrote:
>
> Being a C programmer, Richard extended SQLite to allow C syntax for
> equality and inequality comparisons as shown at
> http://www.sqlite.org/lang_expr.html even though it is non standard.
Actually, the reason I did this was because PostgreSQL did
it
> At first I thought this had solved the problem, because all in house testing
> runs beautifully. However, as soon as the device is sent to the field, the
> error starts again. Unfortunately, it means that I have never been able to
> catch this in debug. I did, however, change the error
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