On Feb 4, 2010, at 5:20 AM, Ron Hudson wrote:
> Pavel Ivanov wrote:
>> String constants should be enclosed in single quotes. Double quotes
>> are for identifiers. So in your case you make perfectly legal no-op
>> action - update field R with value of field R, i.e. leave field R
>> unchanged.
>>
>
I got a quick question. I have two databases, one resides on a read
only file system, the other is on a writable file system. I routinely
copy from the read only copy to the other. I did not realize, until
today, that I do not have the protection of transaction support since
one database is read
I use UPDATE for text columns in the table and any changes are committed to the
hard drive right away (well,
after about 120 ms).
This can be verified by using external tool. I use SQLite Manager to 'see' the
changes.
I use also sqlite3_blob_write(ppBlob,dataToWrite,dataCount,offsetInTheB
On Feb 3, 2010, at 09:58 , Igor Tandetnik wrote:
> Brian Palmer wrote:
>> Hey all, we've painted ourselves into a bit of a corner and we're
>> trying to find the best way out. Through an oversight during initial
>> development, we defined a column as not null in our schema and we
>> need to drop
Pavel Ivanov wrote:
> It works because SQLite knows that people often mix single quotes and
> double quotes. So when it sees something in double quotes it first
> tries to match some identifier to that and if it fails then SQLite
> considers it as a string constant.
>
> Pavel
>
> On Wed, Feb 3, 201
It works because SQLite knows that people often mix single quotes and
double quotes. So when it sees something in double quotes it first
tries to match some identifier to that and if it fails then SQLite
considers it as a string constant.
Pavel
On Wed, Feb 3, 2010 at 5:20 PM, Ron Hudson wrote:
>
Pavel Ivanov wrote:
> String constants should be enclosed in single quotes. Double quotes
> are for identifiers. So in your case you make perfectly legal no-op
> action - update field R with value of field R, i.e. leave field R
> unchanged.
>
> Pavel
>
Thanks Pavel, that works..
Hmm I wonder wh
String constants should be enclosed in single quotes. Double quotes
are for identifiers. So in your case you make perfectly legal no-op
action - update field R with value of field R, i.e. leave field R
unchanged.
Pavel
On Wed, Feb 3, 2010 at 4:43 PM, Ron Hudson wrote:
> I am using the latest ver
I am using the latest version of sqlite3.exe (version 3.6.22) Running
Windows Vista. The sqlite3 executable and
the database file are in a subdirectory of my Documents directory (where
I know rights are not a problem)
In the table named "check", I am trying to update the value in a field
named
On Wed, Feb 03, 2010 at 10:18:01AM -0800, a1rex scratched on the wall:
> ?? I/O data transfer rate - up to 100 Mbps
> ?? Sustained data transfer rate - Up to 58 Mbps
> ?? Average seek time - 8.5ms
> ?? Average latency - 4.16ms
>
> From this data nothing justifies the 120ms update of the r
> Capacity: 120.9 GB
> Speed: 7200 rpm
> Average Read Time:8.5 ms
> ...
> From this data nothing justifies the 120ms update of the record!
Look at 7200 rpm and here http://www.sqlite.org/faq.html#q19.
Pavel
On Wed, Feb 3, 2010 at 1:18 PM, a1rex wrote:
>
> Thank you kindly for all your sugges
>I will try to do something to that extent using timer and character
>counter.
>I hoped that I could update the text stored in the database character
>by character as fast as they come from the keyboard driver.
>Unfortunately updates noticeably slow down the display of typed
>characters.
You
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
lakshmi pathi wrote:
> sqlite3.OperationalError: no such savepoint: pt
pysqlite does all sorts of stuff behind the scenes trying to manage
transactions for you by default. I believe you can set isolation_level to
None to disable that. Else use APSW
Thank you kindly for all your suggestions!
>If you want SQLite to support all ACID properties you cannot change
>anything to speed up updates.
Making sure that I do not loose a character was my primary objective.
> If you are doing bulk updates, and are in a position to re-run the
> data i
As a test, have you tried wrapping your updates in a transaction? That
would isolate if the slow down is the actual writing of the data to
disk.
Where is the file sitting: A local drive, or something across a network
connection?
David
On Wed, 2010-02-03 at 08:51 -0800, a1rex wrote:
> >-
If you want SQLite to support all ACID properties you cannot change
anything to speed up updates. You can only change disks to something
with higher rotation speeds or some non-rotational ones (although I'm
not sure that they will be faster).
Another thing to try is change your application structu
On Tue, Feb 2, 2010 at 11:20 AM, Nicolas Williams
wrote:
> On Tue, Feb 02, 2010 at 09:23:36AM +0100, Sylvain Pointeau wrote:
>> I would be very interested to see some benchmark, just to see.
>
> Feel free to write the relevant program, schema, SQL statements and run
> benchmarks against it. W
a1rex wrote:
> Retraction. Mea Culpa. Back to square one…
> The modified code did not write anything to the drive! But there was
> no error message from the SQLITE.
Why should there be? You have a legal statement - essentially
update notes set note=1 where id='note text';
The condition is not
On Wed, Feb 03, 2010 at 08:51:46AM -0800, a1rex scratched on the wall:
> >- Original Message
> >From: Pavel Ivanov
> >To: General Discussion of SQLite Database
> >Sent: Wed, February 3, 2010 11:37:17 AM
>
> >Just first thought came to my mind: are you sure that 2 versions of
> >code men
Brian Palmer wrote:
> Hey all, we've painted ourselves into a bit of a corner and we're
> trying to find the best way out. Through an oversight during initial
> development, we defined a column as not null in our schema and we
> need to drop that not null constraint.
>
> Since sqlite3 doesn't
>- Original Message
>From: Pavel Ivanov
>To: General Discussion of SQLite Database
>Sent: Wed, February 3, 2010 11:37:17 AM
>Just first thought came to my mind: are you sure that 2 versions of
>code mentioned do the same thing? In particular I'm asserting that
>second version (under #if
Just first thought came to my mind: are you sure that 2 versions of
code mentioned do the same thing? In particular I'm asserting that
second version (under #if 1) doesn't do any actual updating and
doesn't change your database because you have wrong parameter indexes.
And one more question: why do
Hey all, we've painted ourselves into a bit of a corner and we're trying to
find the best way out. Through an oversight during initial development, we
defined a column as not null in our schema and we need to drop that not null
constraint.
Since sqlite3 doesn't support altering columns, I know
>From: Jens Miltner
>Sent: Wed, February 3, 2010 9:46:06 AM
>Just another thought to consider: depending on the amount of non-ASCII
>(or non-roman) string data stored in your database, in may be more
>efficient to use UTF-8 encoding rather than UTF-16 encoding:
>UTF-8 takes up less space for
I just encountered very curious case in Sqlite.
I have very simple data base with only one table and one index:
"CREATE TABLE IF NOT EXISTS notes(id INTEGER PRIMARY KEY, note TEXT)";
My updates to the simple text database were very slow. Extremely slow!
I changed my code and achieved 1000 speed
Am 01.02.2010 um 00:02 schrieb a1rex:
> I am planning to store text in a database which has to accommodate a
> few international languages.
> In this case I have to use UTF-16LE encoding for my TEXT fields.
> I know that once an encoding has been set for a database, it cannot
> be changed.
J
Hi All,
I'm Ramesh, currently we are using sqlite-3.5.8 version,
mainly(sqlite3.h and sqlite3.c) files
API to perform DB operations like 1) insert to,
2) delete from,
3) select from,
Hi all,
I'm working on a sqlite3 with python program.Here is the code snippet
def save_point(self):
self.db.execute("savepoint pt;")
print "Save point created"
self.cursor.execute("insert into STK values(33)")
self.db.execute("r
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