Michael Sizaki [EMAIL PROTECTED] wrote:
What has changed in 3.3.8 to make it so slow?
There were no changes to the query optimizer between 3.3.7
and 3.3.8. None. Nada. Zilch.
--
D. Richard Hipp [EMAIL PROTECTED]
Im not sure that the current situation of forced thread
incompatibility is better than leaving it up to users to manage the
threading. Usually it is assumed that a library is thread unsafe
unless otherwise specified.
Developing multithreaded applications is difficult, i wouldnt dispute
that.
In general worker threads is not an efficient solution to the problem
even if parallelism is available. There is nothing to be gained by
having one thread handing off A to another set of worker threads
because you have to synchronise on whatever queue/list/pipe you use to
transfer the
--- Emerson Clarke [EMAIL PROTECTED] wrote:
Developing multithreaded applications is difficult, i wouldnt dispute
that. But i do dispute the wisdom of actively making a library
incompatible with threads.
Actively? That's a bit much.
There are constraints on the ability to pass SQLite
Does anyone know how I can connect to an sqlite db with coldfusion?
I was trying to do that with ODBC but it doesn't work like I want it to
work.
Does anyone have another id?
Greetz
Kurt
Where can i find a tutorial with examples of how to use LEMON parser...
because i need to build interpreted language
Thanks to all
--
Cesar Rodas
http://www.phpclasses.org/grank (A PHP implementation of PageRank)
Ethereal make use of Lemon
On Fri, 2006-12-29 at 11:08 -0400, Cesar Rodas wrote:
Where can i find a tutorial with examples of how to use LEMON parser...
because i need to build interpreted language
Thanks to all
__
Scanned and protected by Email scanner
== SUMMARY ==
== There is indeed no difference between 3.3.7 and 3.3.8
== However, sqlite hits the disk a lot in a temp file??!!
== PRAGMA temp_store = MEMORY; helps
== Why is sqlite hitting the disk with a 70MB database?
Further tests shows that there is no difference between
3.3.7 and 3.3.8.
Emerson Clarke [EMAIL PROTECTED] wrote:
Im not sure that the current situation of forced thread
incompatibility is better than leaving it up to users to manage the
threading. Usually it is assumed that a library is thread unsafe
unless otherwise specified.
Developing multithreaded
Here's the screenshot showing the resource usage of the slow query:
time ./sqlite3.3.8.exe db.sqlite SELECT * FROM files where id 20 ORDER BY
size, name;|wc
19 204598 24676875
real4m49.947s
user0m18.386s
sys 0m13.318s
Peak memory 35 MB
Michael Sizaki [EMAIL PROTECTED] wrote:
What surprises me, is that the temp file is not kept in
cache. I have 2GB of memory and much bigger files can be
kept in cache. Why is sqlite hitting the disk? What is
going on here? The maximum file cache needed would be 70 MB
for the database + 75
Actually I am trying to retrieve values in a single step.
My queries need to be something like,
select count(*) from tbl1 where state='Normal';select count(*) from tbl1 where
state='Critical'
I got to have these two as seperate, because if there's any critical need to
display a diff icon, and
Another URL where i can find a tutorial?
On 29/12/06, Lloyd [EMAIL PROTECTED] wrote:
Ethereal make use of Lemon
On Fri, 2006-12-29 at 11:08 -0400, Cesar Rodas wrote:
Where can i find a tutorial with examples of how to use LEMON parser...
because i need to build interpreted language
Thanks
[EMAIL PROTECTED] wrote:
Are there some
special flags that SQLite could pass to CreateFileW() to
trick windows into doing a better job of caching temp
files?
FILE_ATTRIBUTE_TEMPORARY
A file is being used for temporary storage. File systems avoid writing
data back to mass storage if sufficient
chetana bhargav
bhargav_chetana-/[EMAIL PROTECTED] wrote:
Actually I am trying to retrieve values in a single step.
My queries need to be something like,
select count(*) from tbl1 where state='Normal';select count(*) from
tbl1 where state='Critical'
Why not
select state, count(*)
where
chetana bhargav [EMAIL PROTECTED] wrote:
Actually I am trying to retrieve values in a single step.
My queries need to be something like,
select count(*) from tbl1 where state='Normal';
select count(*) from tbl1 where state='Critical'
I got to have these two as seperate, because if
http://www.hwaci.com/sw/lemon/lemon.html
Sorry if this link has already been pointed out to you.
http://www.webdotdev.com/nvd/server-side/c/lemon-parser-generator-tutori
al.html
Looks OK but I have not looked at this site before.
Shawn M. Downey
MPR Associates
10 Maxwell Drive, Suite 204
I'm not familiar with Lemon, so I don't know if this will help:
http://linuxgazette.net/106/chirico.html. Also, I'd highly recommend just
doing a Google search for either Lemon Parser or Lemon Tutorial.
--
Eric Pankoke
Founder / Lead Developer
Point Of Light Software
Igor Tandetnik [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
Are there some
special flags that SQLite could pass to CreateFileW() to
trick windows into doing a better job of caching temp
files?
FILE_ATTRIBUTE_TEMPORARY
A file is being used for temporary storage. File systems avoid
* chetana bhargav [EMAIL PROTECTED] [2006-12-29 17:20]:
Actually I am trying to retrieve values in a single step.
My queries need to be something like,
select count(*) from tbl1 where state='Normal';select count(*) from tbl1
where state='Critical'
I got to have these two as seperate,
[EMAIL PROTECTED] wrote:
Perhaps someone with more windows experience can correct
me if my assertion above is incorrect. Are there some
special flags that SQLite could pass to CreateFileW() to
trick windows into doing a better job of caching temp
files?
It seems you've done it right:
Lemon generates C files that could be compiled in Win or Linux Right?
On 29/12/06, Downey, Shawn [EMAIL PROTECTED] wrote:
http://www.hwaci.com/sw/lemon/lemon.html
Sorry if this link has already been pointed out to you.
http://www.webdotdev.com/nvd/server-side/c/lemon-parser-generator-tutori
[EMAIL PROTECTED] wrote:
SELECT count(state='Normal'), count(state='Critical') FROM tbl1;
Wouldn't that just return the number of all rows in tbl1, twice? That
probably should be
SELECT sum(state='Normal'), sum(state='Critical') FROM tbl1;
Igor Tandetnik
* Igor Tandetnik [EMAIL PROTECTED] [2006-12-29 17:35]:
Why not
select state, count(*)
where state in ('Normal', 'Critical')
group by state;
?
Clever!
* [EMAIL PROTECTED] [EMAIL PROTECTED] [2006-12-29 17:40]:
SELECT count(state='Normal'), count(state='Critical') FROM tbl1;
How exactly
Emerson,
You just need to lock the entire transaction using a mutex before hand.
That means each thread will have its own sqlite cache. Reread the sqlite
locking and concurrency guide, you'll see that SQLITE is NOT a transaction
based system such as Postgress/mysql/ oracle. It locks
Joe,
Im interested to know what those constraints are and why ?
The only reason i mentioned shared memory is because it provides a
platform and filesystem agnostic way of handling ipc. Obvioulsy i
dont know the ins and outs of the locking process, but i just thought
it would make sense to have
I went to implement this suggestion and quickly discovered
that SQLite already uses the FILE_ATTRIBUTE_TEMPORARY flag
on TEMP tables. Or at least I think it does. Can somebody
with a symbolic debugger that runs on windows please confirm
that the marked line of code in below (found in os_win.c)
--- [EMAIL PROTECTED] wrote:
On some older versions of Linux, SQLite is unable to pass
database connections from one thread to another. But this
is a problem with the threading libraries used in those older
linux versions and is outside the control of SQLite. I do not
think this issue comes
Greetings!
I need to be able to create a database with a known schema from inside a
program. I used sqlite3.exe's .schema command to export the SQL needed
to create the schema for my new database. I can create the database by
the following steps:
C:\: sqlite3 newdatabase.db
Sqlite3
yes
Shawn M. Downey
MPR Associates
10 Maxwell Drive, Suite 204
Clifton Park, New York 12065
518-371-3983 x113 (work)
860-508-5015 (cell)
-Original Message-
From: Cesar Rodas [mailto:[EMAIL PROTECTED]
Sent: Friday, December 29, 2006 11:47 AM
To: sqlite-users@sqlite.org
Subject: Re:
My last message cites some of the peculiarities of POSIX fcntl() locking.
Search the SQLite mailing list archives for more detailed info as
it pertains to SQLite.
As for having a single unified (locking) model - SQLite already
employs such a strategy as best as is possible given the portable
Richard,
First let me say thank you for your earilier suggestion regarding the
compile time options and overlaoding of the os routines. It was
exactly the kind of information i was searching to for and i am
looking into using that strategy at the moment.
Sorry if ive managed to offend you,
This old mailing list thread better describes this proposed algorithm
to contain all open/close/lock/unlock activity in a single work thread:
http://www.mail-archive.com/sqlite-users@sqlite.org/msg15852.html
--- Joe Wilson [EMAIL PROTECTED] wrote:
As you already know, it's not just Linux -
Ken,
Thanks.
Ok, i think i did miss the point with your test case. I assumed that
it was always possible to perform multiple select, insert, delete, and
update statements within a single transaction anyway. Which i guess
relates to you last point. I dont see why if i have a single global
Open the database as per normal with sqlite3_open(). Then issue the SQL
commands necessary to create your schema. I have a nice little utility I
wrote which will take an SQLite schema dump and convert it to an array of
C strings that you can issue in sequence (and thanks to Microsoft for the
OK, thanks Joe.
I will look up those peculiarities as you suggested, im interested in
understanding what they are.
I agree with you, DRH has done a great job. Sqlite is a fantastic
piece of software and and outstanding example of the way open source
should be. It is small, efficient and
The test server.c code is an example that has a single thread that performs the
DB interactions each client thread, communicates via a queue interface. Each
client will get serialized into the DBserver thread and get its work done.
Thus eliminating any lower level locking and mutexing inside
Ken,
Yes you cannot have multiple threads within the same transaction, and
you cannot pass a connection between threads.
I think we have an undestanding about the performance situation, and
we are getting to the real heart of the issue, which why it is not
possible to have a single transaction,
Clay Dowling clay-diPsFfokYAT2eFz/[EMAIL PROTECTED] wrote:
Open the database as per normal with sqlite3_open(). Then issue the
SQL
commands necessary to create your schema. I have a nice little
utility I
wrote which will take an SQLite schema dump and convert it to an
array of
C strings that
For the record,
The author or authors of this code dedicate any and all copyright
interest in this code to the public domain. We make this dedication
for the benefit of the public at large and to the detriment of our
heirs and successors. We intend this dedication to be an overt act
of
Igor Tandetnik [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
SELECT count(state='Normal'), count(state='Critical') FROM tbl1;
Wouldn't that just return the number of all rows in tbl1, twice? That
probably should be
SELECT sum(state='Normal'), sum(state='Critical') FROM tbl1;
Yes,
On 24/12/06, Adam Megacz [EMAIL PROTECTED] wrote:
AFS (the Andrew FileSystem) supports whole-file locks but not
byte-range locks. Unfortunately, it has a problematic feature
whereby it will claim to grant requests for byte-range locks, but not
actually perform any locking activity. This
On Fri, 29 Dec 2006 12:33:46 -0500, you wrote:
Sqlite3 newdatabase.db .read schemafile.txt
But, when I issue this command from the DOS prompt,
it gives me an error message saying that there
is no command named read.
Try input redirection:
Sqlite3 newdatabase.db schemafile.txt
If your
Hi all,
I have a piece of code that utilizes test_server.c, (master thread)
there are 3 threads, each performing seperate tasks, that get a conection
(shared) and set
PRAGMA read_uncommitted=1.
My understanding is that this would allow each individual thread to
Emereson,
And you can't do this with oracle either, That is create a connection and pass
it around between multiple threads.. Oracle would be very very unhappy if you
did that. Oracle utilizes a context variable to distinguish between threads and
utilizes precompiler flags to enable thread
I have a nice solution that really works well, at least from C...
1. Create a template Database. (using whatever method you like, either
embedded in your code or via sqlite3).
2. Copy the database to a new file, using plane old cp, copy, or if you
like an in code copy using open,
Ken [EMAIL PROTECTED] wrote:
My thought was that if i wanted to perform selects concurrently on SMP
system I would need 2 threads and each thread would be able to read
concurrently
I just don't see how this [test_server.c] improves concurrency...
It improves write concurrancy.
Hi
I am using SQLite to store ngrams from texts (bigrams, trigrams and
tetragrams). This is not really important for the question; just
imagine I have three tables A (int,int), B (int, int, int) and C (int,
int, int, int). As the table keys are full rows and the tables get
big, it is not quite
Regarding:
I need something like:
cat A.db B.db C.db full.db # kidding
-
Hi Alberto,
My first inclination is to consider this a classic use of the
ATTACH DATABASE command
http://www.sqlite.org/lang_attach.html
On 12/29/06, Griggs, Donald [EMAIL PROTECTED] wrote:
Regarding:
I need something like:
cat A.db B.db C.db full.db # kidding
-
Hi Alberto,
My first inclination is to consider this a classic use of the
ATTACH DATABASE
I ran everything through the test_server server and get the following
results when using read_uncommitted=1
rc=[5] msg=[database is locked]
when performing a client_step against a prepared select
statement.
I'd really like to track this down and find out if my code
I think the attach is the way to go, but no need to insert, just select from
the attached databases.
sqlite3 master.db (master is empty).
attach a.db A
attach b.db B
attach c.db C
Then :
select columns from a.A, b.b, c.c where
Alberto Simões [EMAIL
I found part of the issue, in switching servers around the test version did not
enable the shared cache... My fault.. however I still recieved a RC 5 on a
different write operation.
Modifed the test_server code to repost the step and all was well. A better
solution however is to cause the
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Michael Sizaki wrote:
| I'm really puzzled why my system hits the disk so heavily
Windows XP limits the maximum size of the cache (default 10MB!). There
are zillions of pseudo-freeware programs out there to change it. You
can also change it
I'm a fairly competent but amateur Delphi programmer and I can construct all
the SQL statements I need. But I'm having enormous trouble making
sqlite.exe work.
Can some kind person please tell me exactly what, right down to the last
dot and semi-colon, I should type in at the sqlite prompt to
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
You never answered the bit about whether indexing A can be done at the
same time as B. (I get the feeling you have a certain design in mind
and insist that SQLite changes to meet that design, rather than change
your own design around the constraints
On 12/29/06, Michael Hooker [EMAIL PROTECTED] wrote:
I'm a fairly competent but amateur Delphi programmer and I can construct all
the SQL statements I need. But I'm having enormous trouble making
sqlite.exe work.
Can some kind person please tell me exactly what, right down to the last
dot and
Roger,
I have deliberately tried to avoid giving too much detail on the
architecture of the index since that was not the point and i didnt
want to end up debating it.
The design of the index is not the issue, suffice to say that i think
you are over complicating things. It is a desceptively
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