I've noticed that I can use IEEE Infinity values in SQLite by writing
any literal too big for a double.
sqlite> CREATE TABLE foo (x REAL);
sqlite> INSERT INTO foo VALUES (9e999); -- +Inf
sqlite> INSERT INTO foo VALUES (-9e999); -- -Inf
sqlite> INSERT INTO foo VALUES (9e999 / 9e999); -- NaN: gets
Michael Chen wrote:
> --this is my first version for the purpose of storing sparse numerical
> matrix in sql
> --please let me know how to fix the bug at the end of the file, and how to
> tune the performance
> --or any better reference, thanks!
>
> .explain-- return
On Fri, Oct 16, 2009 at 05:34:02PM -0700, Darren Duncan scratched on the wall:
> I believe what you are looking for is the relational operator called DIVIDE,
Yes, this is a text-book example of a Relational "divide." If you
have a table with a key column and an attribute column, and you want
P Kishor wrote:
> I don't even know how to title this post, and it just might be
> something very obvious. Either way, I apologize in advance. Consider
> the following --
>
> sqlite> SELECT * FROM foo;
> a b
> -- --
> 1 6
> 2 6
> 2 3
> 3
I believe what you are looking for is the relational operator called DIVIDE,
which is one of the original ones that E. F. Codd defined (along with (natural
inner) JOIN, UNION, MINUS, PROJECT, RESTRICT, etc) but that very few if any SQL
DBMSs actually implement directly, which is a crying shame.
P Kishor wrote:
> I want the values of ‘a’ for which ‘b’ = 3 AND ‘b’ = 4 (This is just
> an example. In reality, b could be any set of numbers, not just two
> numbers). To illustrate --
> sqlite> SELECT * FROM foo WHERE b = 3;
> a b
> -- --
> 2 3
> 3
I don't even know how to title this post, and it just might be
something very obvious. Either way, I apologize in advance. Consider
the following --
sqlite> SELECT * FROM foo;
a b
-- --
1 6
2 6
2 3
3 3
3 4
3 5
4
yes, that's what I am thinking of too. This big table is in charge of store
all matrix, keep track of all index changes, and rollback when needed. I
will only extract a tiny part from this big table in format like a sparse
matrix, and put it in C array, then the available numerical routines, such
a
On Fri, Oct 16, 2009 at 1:41 PM, Michael Chen
wrote:
> rdbms is indeed not a place for store a single sparse matrix like this.
> However I have hundreds of them, and I need to break them and recombine them
> frequently; furthermore, I need to drop a few rows or columns successively,
> and need to
rdbms is indeed not a place for store a single sparse matrix like this.
However I have hundreds of them, and I need to break them and recombine them
frequently; furthermore, I need to drop a few rows or columns successively,
and need to be able to trace back what's a row's original index. I think
s
thanks Pavel !
On Fri, Oct 16, 2009 at 1:24 PM, Pavel Ivanov wrote:
> > -- IA = [ 1 3 5 7 ] // IA(i) = Index of the first nonzero element
> of
> > row i in A
>
> Why 4th element if A has only 3 rows?
>
> > create temp view rowwiseC as
> > select a1.rowid, sum(a2.ct) +1 as JA
> > from rowwi
On Fri, Oct 16, 2009 at 3:12 PM, Scott Hess wrote:
> On Wed, Oct 14, 2009 at 11:35 PM, John Crenshaw
> wrote:
>> The severe limitations on FTS3 seemed odd to me, but I figured I could
>> live with them. Then I starting finding that various queries were giving
>> strange "out of context" errors wi
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
P Kishor wrote:
> So, what suggestion might you all have for getting around this?
Why not set a busy timeout?
Roger
-BEGIN PGP SIGNATURE-
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iEYEAR
On Fri, Oct 16, 2009 at 3:09 PM, Stephan Wehner wrote:
> On Fri, Oct 16, 2009 at 12:58 PM, Simon Slavin
> wrote:
>>
>> On 16 Oct 2009, at 8:53pm, P Kishor wrote:
>>
>>> If neither the username nor the email exist in the db, then the
>>> application creates a record and informs the user of success
On Wed, Oct 14, 2009 at 11:35 PM, John Crenshaw
wrote:
> The severe limitations on FTS3 seemed odd to me, but I figured I could
> live with them. Then I starting finding that various queries were giving
> strange "out of context" errors with the MATCH operator, even though I
> was following all th
On Fri, Oct 16, 2009 at 12:58 PM, Simon Slavin
wrote:
>
> On 16 Oct 2009, at 8:53pm, P Kishor wrote:
>
>> If neither the username nor the email exist in the db, then the
>> application creates a record and informs the user of success. Except,
>> the previous ajax request (I am assuming it is the p
On 16 Oct 2009, at 8:53pm, P Kishor wrote:
> If neither the username nor the email exist in the db, then the
> application creates a record and informs the user of success. Except,
> the previous ajax request (I am assuming it is the previous ajax
> request from onblur event from the email field)
Yes, I know, if it "hurts when I press here," then I shouldn't "press
here," but, so it goes...
I have an account creation form -- users enter their email and their
desired username, and the form --
onblur from the username field, sends off an ajax request to see if
the desired username already e
> -- IA = [ 1 3 5 7 ] // IA(i) = Index of the first nonzero element of
> row i in A
Why 4th element if A has only 3 rows?
> create temp view rowwiseC as
> select a1.rowid, sum(a2.ct) +1 as JA
> from rowwiseB a1, rowwiseB a2
> where a2.rowid < a1.rowid
> group by a1.rowid
> ;
> --this is not
This is not the answer you are looking for, and there are SQL geniuses
on this list who will help you better, but really, is an rdbms really
a good place to store a matrix the way you are trying to do? So
convoluted.
My approach, if I really was determined to store it in sqlite, would
be to flatte
--this is my first version for the purpose of storing sparse numerical
matrix in sql
--please let me know how to fix the bug at the end of the file, and how to
tune the performance
--or any better reference, thanks!
.explain-- return result in more readable
format
.
On Fri, Oct 16, 2009 at 3:07 PM, Pavel Ivanov wrote:
> Yes, that's right.
>
Ta for the help.
___
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Yes, that's right.
Pavel
On Fri, Oct 16, 2009 at 9:05 AM, Brad Phelan wrote:
> On Fri, Oct 16, 2009 at 2:48 PM, Pavel Ivanov wrote:
>> Yes, pretty interesting results. I didn't expect that. :)
>> Query plan seems to suggest that SQLite executes query not in the way
>> you said but first takes t
On Fri, Oct 16, 2009 at 2:48 PM, Pavel Ivanov wrote:
> Yes, pretty interesting results. I didn't expect that. :)
> Query plan seems to suggest that SQLite executes query not in the way
> you said but first takes tit table, joins epgdata to it and then joins
> tit1 and tit2 to it. So it should be e
Yes, pretty interesting results. I didn't expect that. :)
Query plan seems to suggest that SQLite executes query not in the way
you said but first takes tit table, joins epgdata to it and then joins
tit1 and tit2 to it. So it should be executed faster than you
thought...
I've played with your quer
On Fri, Oct 16, 2009 at 2:08 PM, Brad Phelan wrote:
> On Fri, Oct 16, 2009 at 1:39 PM, Pavel Ivanov wrote:
>>> So if
>>> x has a very large range and a small probability of a match then
>>> we still have to do a full scan of 10,000 rows of A.
>>>
>>> Is there a better way to construct the query a
>> So if
>> x has a very large range and a small probability of a match then
>> we still have to do a full scan of 10,000 rows of A.
>>
>> Is there a better way to construct the query and or indexes so
>> the result is faster.
>
> If your x has a small selectivity in B disregarding of A, i.e. for
>
On Fri, Oct 16, 2009 at 1:39 PM, Pavel Ivanov wrote:
>> So if
>> x has a very large range and a small probability of a match then
>> we still have to do a full scan of 10,000 rows of A.
>>
>> Is there a better way to construct the query and or indexes so
>> the result is faster.
>
> If your x has
> So if
> x has a very large range and a small probability of a match then
> we still have to do a full scan of 10,000 rows of A.
>
> Is there a better way to construct the query and or indexes so
> the result is faster.
If your x has a small selectivity in B disregarding of A, i.e. for
each x you
> Does the BEGIN start a transaction?
No. Triggers work inside transactions that called them.
Pavel
On Fri, Oct 16, 2009 at 5:22 AM, Wenton Thomas wrote:
> For example,
>
>
> CREATE TRIGGER update_customer_address UPDATE OF address ON customers
> BEGIN
> UPDATE orders SET address = new.add
> Therefore, SQLite
> returns SQLITE_BUSY for the first process, hoping that this will
> induce the first process to release its read lock and allow the
> second process to proceed.
[snip]
> In short, you can poke at a SQLITE_BUSY state for a bit, but fairly
> soon you should give
On Oct 16, 2009, at 2:53 PM, Vladimir Looze wrote:
> Sqlite causes Segmentation fault on SQL insert.
>
> Steps to reproduce:
> 1. create database with following schema (table/column names dosen't
> matter)
>
> - BEGIN OF SQL LISTING
> create table tname ( id integer not null primary key asc
how about this
select * from TestName where History > 399 and History < 501
the above SQL is saying (in laymans terms)
>From the table TestName gather all the column data and display ONLY those
rows where data in History column is greater than 399 and is below 501.
_OR_
Select ONLY those r
Hi all,
I am curious on how to design a schema and indexes to best fit the
following pattern. My
data is tree like and stored normalized in the database.
CREATE TABLE A
( id INTEGER PRIMARY
)
CREATE TABLE B
( id INTEGER PRIMARY
, A_ID INTEGER # Foreign key to A
, x INTE
For example,
CREATE TRIGGER update_customer_address UPDATE OF address ON customers
BEGIN
UPDATE orders SET address = new.address WHERE customer_name = old.name;
END;
when updating address ON customers,
then follow a BEGIN ...END statement.
Does the BEGIN start a transaction?
Sqlite causes Segmentation fault on SQL insert.
Steps to reproduce:
1. create database with following schema (table/column names dosen't matter)
- BEGIN OF SQL LISTING
create table tname ( id integer not null primary key asc autoincrement,
cname string );
create table surname ( id inte
Thanks everyone for your suggestions. The locking was caused by not
resetting / finalizing the statements in my transactions.
Thanks again,
David
-Original Message-
From: sqlite-users-boun...@sqlite.org
[mailto:sqlite-users-boun...@sqlite.org] On Behalf Of John Crenshaw
Sent: Friday,
yes, you are right. I'd better to go to sleep now -:)
On Fri, Oct 16, 2009 at 2:23 AM, P Kishor wrote:
> On Fri, Oct 16, 2009 at 1:42 AM, Michael Chen
> wrote:
> > select *, (length(path) - length( replace(path, '/','' )) +1 )
>
> sqlite> SELECT length('/1/2/5/');
> 7
> sqlite> SELECT replace(
On Fri, Oct 16, 2009 at 1:42 AM, Michael Chen
wrote:
> select *, (length(path) - length( replace(path, '/','' )) +1 )
sqlite> SELECT length('/1/2/5/');
7
sqlite> SELECT replace('/1/2/5/', '/', '');
125
sqlite> SELECT length('125');
3
7 - 3 = 4
4 + 1 = 5
sqlite> SELECT (length('/1/2/5/') - leng
39 matches
Mail list logo
