Maksim Yevmenkin wrote:
>
>>>so, just with plain ascii file i get four times the speed i get with
>>>sqlite. note that my c program will scale linearly with the size of
>>>dataset (just like i see with sqlite).
>>>
>>>
>> With anything related to computers, there are always tradeoffs - mos
John.
> >i think, i know what is going on here. the problem is that every time
> >i do an indexed scan sqlite has to
> >
> >1) fetch index pages
> >
> >2) fetch data pages that match "where" condition
> >
> >because both index and data are in the same file sqlite has to perform
> >insane amount of
Hello all,
What is the best way to copy (not move) a table between an existing
database and a blank, attached database using SQLite v3? The COPY
command is gone, what else can I use?
Thank you.
Dennis
> > SELECT count(*) FROM (SELECT a,n1 FROM data WHERE a <= 18234721 GROUP BY a);
> >
> > > time sqlite3 db < test.sql
> > 30
> > 1024
> > 1417
> > 13.14u 1.06s 0:14.40 98.6%
>
> Have you tried doing the query like this:
>
> SELECT count(*) FROM (SELECT a,nl FROM data WHERE a-18234721<=0 GRO
Maksim Yevmenkin wrote:
i think, i know what is going on here. the problem is that every time
i do an indexed scan sqlite has to
1) fetch index pages
2) fetch data pages that match "where" condition
because both index and data are in the same file sqlite has to perform
insane amount of seek() calls
On Tue, 2005-04-12 at 16:17 -0700, Maksim Yevmenkin wrote:
> SELECT count(*) FROM (SELECT a,n1 FROM data WHERE a <= 18234721 GROUP BY a);
>
> > time sqlite3 db < test.sql
> 30
> 1024
> 1417
> 13.14u 1.06s 0:14.40 98.6%
>
Have you tried doing the query like this:
SELECT count(*) FROM (SEL
Thomas,
> > with sum(n1) added query runs twice as slow. as i was told its because
> > sqlite has to fetch data row. fine, but why its soo slow?! and it
>
>Because for each row it has to compute the aggregate key, find the
> aggregator for that key and increment the sum for that aggregate key
On 4/12/05, Thomas Briggs <[EMAIL PROTECTED]> wrote:
>
>Aliases rowid to rowid seems to work for me, i.e.
Aha. I forgot about that trick. Thanks!
Aliases rowid to rowid seems to work for me, i.e.
SELECT rowid as rowid, primary_key_col
-Tom
> -Original Message-
> From: Will Leshner [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, April 12, 2005 5:36 PM
> To: sqlite-users@sqlite.org
> Subject: [sqlite] determing the primary key
>
> with sum(n1) added query runs twice as slow. as i was told its because
> sqlite has to fetch data row. fine, but why its soo slow?! and it
Because for each row it has to compute the aggregate key, find the
aggregator for that key and increment the sum for that aggregate key.
That's a lot mo
On Apr 12, 2005 8:10 PM, Reid Thompson <[EMAIL PROTECTED]> wrote:
> D. Richard Hipp wrote:
> > On Tue, 2005-04-12 at 11:53 -0400, Reid Thompson wrote:
> >> This issues still exists:
> >> http://www.mail-archive.com/sqlite-users@sqlite.org/msg06857.html
> >>
> >> reid
> >>
> >
> > Perhaps someone wh
I realize that in sqlite 3, if I construct a query with 'rowid' as one
of the columns, and the table I am querying explicitly declares an
integer primary key column, my results have the table's name for the
column and not 'rowid'. What I'm wondering is if there is a good way
to determine which of t
Dear SQLite users,
consider this
schema
-
sqlite> .schema data
CREATE TABLE data(
a INTEGER,
b INTEGER,
c CHAR,
d INTEGER,
e INTEGER,
n1 FLOAT,
n2 FLOAT
);
CREATE INDEX data_by_a on data (a);
data set
-
sqlite> select count(*) from data where a <= 18234721;
92
D. Richard Hipp wrote:
> On Tue, 2005-04-12 at 11:53 -0400, Reid Thompson wrote:
>> This issues still exists:
>> http://www.mail-archive.com/sqlite-users@sqlite.org/msg06857.html
>>
>> reid
>>
>
> Perhaps someone who has access to cygwin on Windows XP can
> suggest a fix. (I do not own a copy o
Gé,
thanks for the suggestion. unfortunately it did not make any
difference :( below is the results. as you can see it takes 7+ seconds
to "group by" 333,392 records and i'm grouping by column on which i
have index. again, i'm not a database guy, but i think that is slow.
perhaps someone can comm
On Tue, 2005-04-12 at 11:53 -0400, Reid Thompson wrote:
> This issues still exists:
> http://www.mail-archive.com/sqlite-users@sqlite.org/msg06857.html
>
> reid
>
Perhaps someone who has access to cygwin on Windows XP can suggest
a fix. (I do not own a copy of WinXP so it would be rather diffic
This issues still exists:
http://www.mail-archive.com/sqlite-users@sqlite.org/msg06857.html
reid
Maksim,
Some things you could try:
1) increase cache memory
You may be causing a lot of cache misses if the size of the query result
is very large compared to the size of the cache. Index-based searches
can cause multiple reloads of the same page because of a lack of
locality in the cache. An in
The comment that was added at the same time as the assertion
was commented out explains it pretty well.
If behaviour when the system fails to allocate memory is
important to you, I recommend upgrading to version 3.
Version 3 handles this condition much more reliably than
version 2 does.
It do
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