I'd be interested in knowing the performance improvements your able to
achieve from threading. I would be in debt if you'd post the results.
cheers
jason
-Message d'origine-
De : Dennis Volodomanov [mailto:[EMAIL PROTECTED]
Envoye : mardi 27 mars 2007 04:35
A : sqlite-users@sqlite.org
On Mon, 2007-03-26 at 17:08 +0200, Vivien Malerba wrote:
> On 3/26/07, Martin Jenkins <[EMAIL PROTECTED]> wrote:
> > Vivien Malerba wrote:
> > > Hi!
> > >
> > > I've got an error reporting problem when trying to insert a row which
> > > breaks a UNIQUE constraint in a table in a C program, I get th
i use framework v1.1 (2003) not framework v2
Samuel R. Neff wrote:
>
>
> If you're using ASP.NET I'd suggest using the ADO.NET wrapper available
> here: http://sqlite.phxsoftware.com/
>
> It's an excellent implementation of ADO.NET for SQLite and would be far
> less
> trouble than using sqli
AFAIK The behavior you're looking for is not well defined by the JDBC API:
http://java.sun.com/j2se/1.4.2/docs/api/java/sql/Statement.html
http://java.sun.com/j2se/1.4.2/docs/api/java/sql/Statement.html#addBatch(java.lang.String)
Perhaps some JDBC drivers implement the behavior you expect, but
[EMAIL PROTECTED] writes:
> The sqlite3_prepare()/sqlite3_step() API only executes a single
> statement. The sqlite3_prepare() routine returns a pointer to
> the next statement if you give it a list of statements.
I see. It looks like the JDBC driver punts on using the pzTail
parameter¹:
,
"Steven E. Harris" <[EMAIL PROTECTED]> wrote:
>
> Does SQLite normally execute more than one statement provided in a SQL
> string?
The sqlite3_prepare()/sqlite3_step() API only executes a single
statement. The sqlite3_prepare() routine returns a pointer to
the next statement if you give it a li
What version if DB2 is this? Is your DB2 engine storing data in EBCDIC
format? What platform is the SQLite database on, and you didn't mention
the SQLite version.
If your DB2 data is EBCDIC did you convert it to ASCII before putting it
in SQLite? I want to point out the difference between an
Yes, threading is one option I'm testing and timing as well.
> -Original Message-
> From: Joe Wilson [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, March 27, 2007 12:29 PM
> To: sqlite-users@sqlite.org
> Subject: RE: [sqlite] Questions on views
>
> Assuming you're running on multi-core mach
Assuming you're running on multi-core machines, spread the work over a few
threads/connections.
--- Dennis Volodomanov <[EMAIL PROTECTED]> wrote:
> Oops - that last sentence I wrote actually doesn't make sense :) I know
> what prepared statements are as I'm using them (doh!). I might have a
> prob
I'm using the "pure" SQLite JDBC driver¹ and trying to bootstrap my
database schema by running a batch of DDL statements. I read in the
entire DDL script from a file, collect it into a string, and feed that
string into either java.sql.Statement.executeUpdate() or
java.sql.Statement.executeBatch().
occur when this is the case.
>
> There is a plot of runtime of CVSHEAD versus version 3.3.13
> at
>
>http://www.sqlite.org/relspeed-20070326-ephemeral.gif
>
> (As the name implies, this GIF will ephemeral. Do not expect it
> to be there for more than a few days.)
elease its EXCLUSIVE lock after its does its
first write until you either close the connection or you
do "PRAGMA locking_mode=NORMAL". There are various optimizations
that can occur when this is the case.
There is a plot of runtime of CVSHEAD versus version 3.3.13
at
http://www.s
Oops - that last sentence I wrote actually doesn't make sense :) I know
what prepared statements are as I'm using them (doh!). I might have a
problem that I need to add more WHERE conditions to those "basic"
statements, which wouldn't work probably with storing them, as I can't
possible know all po
Thanks for the reply!
I'm not really trying to blame SQLite here, as I know there're limits on
just how fast it can prepare a statement, execute it and give me the
results - and it's fast, I'm just looking for ways to make it faster.
The reason that such a huge amount of statements needs to be ex
--- Dennis Volodomanov <[EMAIL PROTECTED]> wrote:
> Yes, after timing both I found that SELECT EXISTS is actually a tiny bit
> faster, which does matter when multiplied by thousands of executions in
> a row.
>
> Unfortunately, I still cannot get it as fast as I want - it takes
> approximately 1500
Vivien Malerba wrote:
Here is a sample test case, just uncompress, run "make" and "./test".
Here is what I get using SQLite 3.3.13 (On Linux):
SQL error (step): SQL logic error or missing database
SQL error (step): column name is not unique
It shows that calling sqlite3_reset() seems to be requi
Yes, after timing both I found that SELECT EXISTS is actually a tiny bit
faster, which does matter when multiplied by thousands of executions in
a row.
Unfortunately, I still cannot get it as fast as I want - it takes
approximately 1500-2000 ms per approximately 2000-3000 executions. Is
there any
Joel Cochran wrote:
I do think more and more that the solution for me is to trim the trailing
blanks before INSERTing them into SQLite.
That will be your best solution, and it will make your database files
smaller too since sqlite won't be storing the trailing spaces.
Dennis Cote
-
> From: Joel Cochran [mailto:[EMAIL PROTECTED]
>
> Hi Puneet,
>
> I probably shouldn't have said that they 'ignore' the blanks, but they
are
> capable of treating them as white space for text matching purposes. I
> can't
> speak for Oracle, but I'm pretty sure MySQL and SqlServer (and I know
for
Hello Joel,
Why not strip the spaces before insertion?
C
Monday, March 26, 2007, 4:36:02 PM, you wrote:
JC> Howdy all,
JC> I am new to SQLite, so I hope this isn't too much of a newbie question, but
JC> I searched the Internet, the archives, and the help docs and could not find
JC> any mention
Hi Puneet,
I probably shouldn't have said that they 'ignore' the blanks, but they are
capable of treating them as white space for text matching purposes. I can't
speak for Oracle, but I'm pretty sure MySQL and SqlServer (and I know for
sure DB2) all allow you to search on 'A' and they will retur
On 3/26/07, Joel Cochran <[EMAIL PROTECTED]> wrote:
Howdy all,
I am new to SQLite, so I hope this isn't too much of a newbie question, but
I searched the Internet, the archives, and the help docs and could not find
any mention of this.
I am populating an SQLite database from a legacy IBM AS/400
Howdy all,
I am new to SQLite, so I hope this isn't too much of a newbie question, but
I searched the Internet, the archives, and the help docs and could not find
any mention of this.
I am populating an SQLite database from a legacy IBM AS/400 database. The
400 stores all character fields with
On 3/26/07, Joe Wilson <[EMAIL PROTECTED]> wrote:
--- Alberto Simões <[EMAIL PROTECTED]> wrote:
> The tables are related but they are already being created in parallel
> (three tables). I was joining them just because it was easier to move.
> But given the new, erm, big size, I think I'll maintai
Had a good look at this now and doing:
delete from tableB
where not exists
(select id from tableA where tableA.id = tableB.id)
Is indeed quite a bit faster than doing:
delete from tableB
where id not in
(select tableA.id from tableA)
In my case about 3 times as fast.
Looking at the query plan w
--- Joe Wilson <[EMAIL PROTECTED]> wrote:
> > improved dramatically. So I attempted the creation of the index off hours on
> > the production system, and after 4 hours no index. I can't detect any
> > activity at all. The journal file and the .db file just sit at the same size
> > for 4 hours. Wh
--- Alberto Simões <[EMAIL PROTECTED]> wrote:
> The tables are related but they are already being created in parallel
> (three tables). I was joining them just because it was easier to move.
> But given the new, erm, big size, I think I'll maintain them split.
>
> Joe Wilson idea of attaching the
Iulian Musat wrote:
Hello everybody !
First of all I have to say that I'm a fairly new user of SQLite, so be
kind :-)
The problem is with the "round" function: the result have a decimal
point even if the second argument is zero (the default):
sqlite> select round(1.234);
1.0
sqlite> select
[EMAIL PROTECTED] wrote:
I will need an index on that field later, but
I could drop it prior to the delete and create
a new one after.
Don't do that. If you need the index, then leave it as is.
Thinking about it I am not sure in any case of the
value of an index after deletes on a table.
<[EMAIL PROTECTED]> wrote:
>
> I am not aware of a BOOLEAN type.
> The types defined in the website are: NULL, INTEGER, REAL, TEXT and BLOB.
> Is BOOLEAN a hidden type?
>
BOOLEAN is not a different type. What Dennis meant was that
integer values 0 and 1 are stored more efficiently in the new
Brian Johnson wrote:
Another way of saying what Dennis said (I had to read his reply twice before I
understood it):
Point taken. :-)
I often think I'm being too wordy in my replies, but when I try to make
my statements more succinct they seem to be confusing.
I guess I just don't have th
Dennis Cote <[EMAIL PROTECTED]> wrote:
> John Stanton wrote:
> > It does not have fixed length columns except for the ones which hold
> > integer and real numbers and boolean values.
> >
> Actually, integers are stored in a variable length format as well. It
> takes less space to store sma
Hello everybody !
First of all I have to say that I'm a fairly new user of SQLite, so be
kind :-)
The problem is with the "round" function: the result have a decimal
point even if the second argument is zero (the default):
sqlite> select round(1.234);
1.0
sqlite> select round(1.234,0);
1.0
On 3/26/07, Eduardo Morras <[EMAIL PROTECTED]> wrote:
At 17:22 26/03/2007, you wrote:
>Hi
>
>I have a database with three tables (bigrams, trigrams and
>tetragrams). Basically, they are:
> TABLE( A, B, Count) IDX(A,B) IDX(B)
> TABLE( A, B, C, Count) IDX(A,B,C) IDX(B) IDX(C)
> TABLE( A, B,
> also, as Dennis said .. unless you have
> some other reason for that index on
> Table B, get rid of it.
I will need an index on that field later, but
I could drop it prior to the delete and create
a new one after.
Thinking about it I am not sure in any case of the
value of an index after delete
Another way of saying what Dennis said (I had to read his reply twice before I
understood it):
your query: for every record in TableB it returns ALL the records in tableA
and then looks through them
Dennis's query: for every record in TableB it checks tableA directly for the
existence of that ID
At 17:22 26/03/2007, you wrote:
>Hi
>
>I have a database with three tables (bigrams, trigrams and
>tetragrams). Basically, they are:
> TABLE( A, B, Count) IDX(A,B) IDX(B)
> TABLE( A, B, C, Count) IDX(A,B,C) IDX(B) IDX(C)
> TABLE( A, B, C, D, Count) IDX (A,B,C,D) IDX(B) IDX(C) IDX(D)
>
>Now,
Thanks, will try that and report back.
RBS
> I'm not sure if SQLite support this syntax, but try following statement,
>
> Delete from tableB b
> Where not exist ( select 'x'
> from tableA a
> where a.id = b.id )
>
> -Original Message-
> From: Dennis Cot
--- Alberto Simões <[EMAIL PROTECTED]> wrote:
> I have a database with three tables (bigrams, trigrams and
> tetragrams). Basically, they are:
>TABLE( A, B, Count) IDX(A,B) IDX(B)
>TABLE( A, B, C, Count) IDX(A,B,C) IDX(B) IDX(C)
>TABLE( A, B, C, D, Count) IDX (A,B,C,D) IDX(B) IDX(C
--- Dennis Cote <[EMAIL PROTECTED]> wrote:
> Dennis Volodomanov wrote:
> > Is doing a SELECT EXISTS (...) faster than a SELECT COUNT (... LIMIT 1)
> > or would it be the same (I would expect them to be the same, but that's
> > only my guess)?
> >
> I would expect them to be very nearly the same.
I'm not sure if SQLite support this syntax, but try following statement,
Delete from tableB b
Where not exist ( select 'x'
from tableA a
where a.id = b.id )
-Original Message-
From: Dennis Cote [mailto:[EMAIL PROTECTED]
Sent: 26 March 2007 16:12
To:
Thanks Dennis, will try that when I get chance (at work now) and will
report back about the difference
it made.
RBS
> RB Smissaert wrote:
>> Simplified I have the following situation:
>>
>> 2 tables, tableA and tableB both with an integer field, called ID,
>> holding
>> unique integer numbers in
Hi
I have a database with three tables (bigrams, trigrams and
tetragrams). Basically, they are:
TABLE( A, B, Count) IDX(A,B) IDX(B)
TABLE( A, B, C, Count) IDX(A,B,C) IDX(B) IDX(C)
TABLE( A, B, C, D, Count) IDX (A,B,C,D) IDX(B) IDX(C) IDX(D)
Now, this database is quickly getting around
RB Smissaert wrote:
Simplified I have the following situation:
2 tables, tableA and tableB both with an integer field, called ID, holding
unique integer numbers in tableA and non-unique integer numbers in tableB.
Both tables have an index on this field and for tableA this is an INTEGER
PRIMARY K
On 3/26/07, Martin Jenkins <[EMAIL PROTECTED]> wrote:
Vivien Malerba wrote:
> Hi!
>
> I've got an error reporting problem when trying to insert a row which
> breaks a UNIQUE constraint in a table in a C program, I get the
> following error with sqlite3_errmsg():
> "SQL logic error or missing data
On 3/25/07, stripe <[EMAIL PROTECTED]> wrote:
using sqlite version 3.3.13.
... extern "C" { #include } ...
doesn't help :(
Well, that seems like a compiler problem, not a SQLite related one.
For some reason the compiler is treating the SQLite header file as C++
code, when it should be trea
P Kishor wrote:
interesting. As far as _I_ know, the first implementation of varint!
No, this idea has been around for a long time. It was used for ISDN
addressing for example. I'm sure it is probably in Knuth somewhere. It
is still a very good idea though.
is it reasonable to assume tha
Dennis Volodomanov wrote:
Is doing a SELECT EXISTS (...) faster than a SELECT COUNT (... LIMIT 1)
or would it be the same (I would expect them to be the same, but that's
only my guess)?
I would expect them to be very nearly the same. Any difference would
only be apparent if you repeat them m
What operations/work patterns will benefit most from
PRAGMA locking_mode = EXCLUSIVE?
Can you roughly quantify the speedups in such cases?
TV dinner still cooling?
Check out "Tonight's Picks" on Yahoo! TV.
h
Vivien Malerba wrote:
Hi!
I've got an error reporting problem when trying to insert a row which
breaks a UNIQUE constraint in a table in a C program, I get the
following error with sqlite3_errmsg():
"SQL logic error or missing database"
If I fire the sqlite3 program and run the same SQL query,
P Kishor wrote:
On 3/25/07, fangles <[EMAIL PROTECTED]> wrote:
SQLite doesn't truncate anything. Whatever you put in you get out. If
you see a truncation, it is either done by whatever wrapper you use on
top of SQLite, or simply an artifact of the way you inspect the data
(e.g. you look at the
On 3/26/07, Dennis Cote <[EMAIL PROTECTED]> wrote:
John Stanton wrote:
> It does not have fixed length columns except for the ones which hold
> integer and real numbers and boolean values.
>
Actually, integers are stored in a variable length format as well. It
takes less space to store smaller in
John Stanton wrote:
It does not have fixed length columns except for the ones which hold
integer and real numbers and boolean values.
Actually, integers are stored in a variable length format as well. It
takes less space to store smaller integer values than it does to store
large values. This
Hi!
I've got an error reporting problem when trying to insert a row which
breaks a UNIQUE constraint in a table in a C program, I get the
following error with sqlite3_errmsg():
"SQL logic error or missing database"
If I fire the sqlite3 program and run the same SQL query, I get the
following err
On 3/25/07, fangles <[EMAIL PROTECTED]> wrote:
SQLite doesn't truncate anything. Whatever you put in you get out. If
you see a truncation, it is either done by whatever wrapper you use on
top of SQLite, or simply an artifact of the way you inspect the data
(e.g. you look at the string in a debug
If you're using ASP.NET I'd suggest using the ADO.NET wrapper available
here: http://sqlite.phxsoftware.com/
It's an excellent implementation of ADO.NET for SQLite and would be far less
trouble than using sqlite directly from .NET code.
HTH,
Sam
---
We'
fangles wrote:
SQLite doesn't truncate anything. Whatever you put in you get out. If
you see a truncation, it is either done by whatever wrapper you use
on top of SQLite, or simply an artifact of the way you inspect the
data (e.g. you look at the string in a debugger, and the debugger
just ha
i use dlls to connect to sqlite db(in asp.net).
i have a problem:
when the database file (sample.db) is opened
with a windows application (and in use - not closed),
i can not open that database with a web application.
in other words :
how can i open an opened database with a web application?
t
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