On 15 Dec 2015, at 11:47pm, Hamdan Alabsi
wrote:
> Also, does sqlite support client-server database engine ?
No. Your program calls SQLite API routines. Those routines read and write the
file. There is no server.
Simon.
hi,all
There are two ways to open a database.
1.sqlite3_open
2.ATTACH DATABASE
Because there are so many data base. So we used attach database to open
them.
But the efficiency of the programming is not ideal.
which one is faster?
Is the efficiency between
I mean only compare the two ways of get the database handl.
1.sqlite3_open
2.ATTACH DATABASE
Do not consider the next operation, such as select,update and so on.
At 2015-12-16 10:51:31, "Richard Hipp" wrote:
>On 12/15/15, ??? <2004wqg2008 at 163.com> wrote:
>> hi,all
>> There
After testing the Sqlite3_open and ATTACH DATABASE,
I found that the attach database is slower than sqlite3_open.
there is attachment after the mail which includ the speed information (
millisecond ).
At 2015-12-16 10:59:27, "Richard Hipp" wrote:
>On 12/15/15, ???
After testing the Sqlite3_open and ATTACH DATABASE,
I found that the attach database is slower than sqlite3_open.
there is attachment after the mail which includ the speed information (
millisecond ).
??? <2004wqg2008 at 163.com> wrote:
>
> After testing the Sqlite3_open and ATTACH DATABASE,
> I found that the attach database is slower than sqlite3_open.
> there is attachment after the mail which includ the speed
> information ( millisecond ).
Your attachment
On Tue, Dec 15, 2015 at 11:19 PM, Dominique Pell? wrote:
> ??? <2004wqg2008 at 163.com> wrote:
>
> >
> > After testing the Sqlite3_open and ATTACH DATABASE,
> > I found that the attach database is slower than sqlite3_open.
> > there is attachment after the mail which
Is it possible to have an index on a computer value?
E.g. I have a 40 byte value in one of my columns. I only want an index over the
first 4 bytes of it.
However, I don't really want to repeat those 4 bytes inside another column on
the main table.
Is there any way to accomplish that?
-
Scott Robison wrote:
> On Tue, Dec 15, 2015 at 11:19 PM, Dominique Pell? gmail.com
>> wrote:
>
>> ??? <2004wqg2008 at 163.com> wrote:
>>
>> >
>> > After testing the Sqlite3_open and ATTACH DATABASE,
>> > I found that the attach database is slower than sqlite3_open.
>> >
This has been discussed several times on the list. SQLite (and all other
databases) try very hard to resolve the names you refer to in your query and
will search all the tables you mention to find *unqualified* references. They
give up if they do not find exactly one definition.
Try " delete
Hi Hamdan,
These are some very basic questions (as others have mentioned), and may
not be your only questions at this point. To fully understand how SQLite
implements databasing and what it is best suited for (or what it isn't
useful for), your best bet is to take a look at these pages:
On 12/16/2015 12:51 PM, ??? wrote:
> After testing the Sqlite3_open and ATTACH DATABASE,
> I found that the attach database is slower than sqlite3_open.
> there is attachment after the mail which includ the speed
> information ( millisecond ).
Hi,
This mailing list
On 12/16/2015 03:17 PM, Deon Brewis wrote:
> Is it possible to have an index on a computer value?
>
>
> E.g. I have a 40 byte value in one of my columns. I only want an index over
> the first 4 bytes of it.
>
>
> However, I don't really want to repeat those 4 bytes inside another column on
> the
Thanks for everyone.
You are right. According to you help, I understand the problem.
Just open or attach database , open operation is faster than attach database.
if add a query statement after open or attach database. The time which they
cost almost the same.
Best regards.
what Dominique
16 dec 2015, James K. Lowden:
> On Fri, 11 Dec 2015 16:21:30 +0200
> "Frank Millman" wrote:
>
>> sqlite> UPDATE fmtemp SET balance = balance + 123.45;
>> sqlite> SELECT bal FROM fmtemp;
>> 5925.599
>
> To a question like that you'll receive a lot of answers about
> numerical
>
On 16 Dec 2015, at 8:37am, Dominique Pell? wrote:
> Having said all that, reading https://www.sqlite.org/c3ref/open.html
> I see no mention of the fact that sqlite3_open*() is lazy.
> Is it documented somewhere?
Not in the official SQLite documentation. But it is easy to prove. Just open
a
> Hello, so in short, rounding the column anywhere it is used, is
> another solution. I confirmed this below. Thanks, E. Pasma.
>
> BEGIN;
> UPDATE fmtemp SET bal = ROUND(bal,2) + 123.45;
> (repeat a 1.000.001 times
> END;
> SELECT bal FROM fmtemp;
> 123450123.45
Absolutely not! You should
Hello !
I said once and I'll say again for some applications it would make sense to
use _Decimal64 (_Decimal32, _Decimal128) instead of floating points.
Even if it's done in software the performance is acceptable on most common
cases.
See a sqlite3.c/sqlite3.h modified to use "_Decimal64"
16 dec 2015, Keith Medcalf:
>> BEGIN;
>> UPDATE fmtemp SET bal = ROUND(bal,2) + 123.45;
>> (repeat a 1.000.001 times
>> END;
>> SELECT bal FROM fmtemp;
>> 123450123.45
>
> You should NEVER round as you have done above. You may get lucky
> and the errors may cancel each other out, or you may get
On Wed, Dec 16, 2015 at 9:43 AM, Keith Medcalf wrote:
>
>> Hello, so in short, rounding the column anywhere it is used, is
>> another solution. I confirmed this below. Thanks, E. Pasma.
>>
>> BEGIN;
>> UPDATE fmtemp SET bal = ROUND(bal,2) + 123.45;
>> (repeat a 1.000.001 times
>> END;
>> SELECT
Good day,
As a matter of interest, when calculating interest on a sum of money
expressed in pennies, how do you handle int arithmetic truncating?
Is that an accounting design rule thing when dealing with fractions of
a penny to round?
Is this an arbitrary quantization? Once upon a time there
On 16 Dec 2015, at 3:46pm, Adam Devita wrote:
> As a matter of interest, when calculating interest on a sum of money
> expressed in pennies, how do you handle int arithmetic truncating?
> Is that an accounting design rule thing when dealing with fractions of
> a penny to round?
When writing
On Wed, Dec 16, 2015 at 1:54 PM, Simon Slavin wrote:
>
> On 16 Dec 2015, at 3:46pm, Adam Devita wrote:
>
> When writing accounting software, there will be a specific rule for rounding
> attached to each calculation. For instance a process for working out a
> mortgage will include its own
On Wed, Dec 16, 2015 at 9:17 AM, Deon Brewis wrote:
> Is it possible to have an index on a computer value?
>
> E.g. I have a 40 byte value in one of my columns. I only want an index over
> the first 4 bytes of it.
>
> However, I don't really want to repeat those 4 bytes inside another column on
On 16 Dec 2015, at 4:23pm, Zsb?n Ambrus wrote:
> See http://sqlite.org/expridx.html
"The ability to index expressions was added to SQLite with version 3.9.0 in
October of 2015"
Nice to see that the development team's crystal ball is running around three
months ahead of questions on this
16 dec 2015, 16:17, Bernardo Sulzbach:
>
> On Wed, Dec 16, 2015 at 12:05 PM, E.Pasma wrote:
>
>> Ok this does not work of any scale of numbers. But a solution with
>> integers
>> neither does
>>
>> E.Pasma
>>
> ...I like integer better than floating points and text for
> currencies ...
Good
On 2015/12/16 4:05 PM, E.Pasma wrote:
> 16 dec 2015, Keith Medcalf:
>>> BEGIN;
>>> UPDATE fmtemp SET bal = ROUND(bal,2) + 123.45;
>>> (repeat a 1.000.001 times
>>> END;
>>> SELECT bal FROM fmtemp;
>>> 123450123.45
>>
>> You should NEVER round as you have done above. You may get lucky and
>>
On Wed, Dec 16, 2015 at 1:37 AM, Dominique Pell?
wrote:
> Scott Robison wrote:
>
> > Why would that be of benefit to you? Are you intending to attach a
> database
> > and never use it? It seems to me the same amount of time will be taken
> > either way.
> >
> > When it comes to opening a
On Sun, 13 Dec 2015 20:11:32 -0700
Scott Robison wrote:
> > It's not fixed, although gacial progress is being made. Even though
> > we've had the TZ database & Posix datetime functions since 1986, 30
> > years later we're still struggling with it, and not only on Windows.
>
> The problem would
On Wed, 16 Dec 2015 20:33:40 +0200
R Smith wrote:
> > Ok this does not work of any scale of numbers. But a solution with
> > integers neither does
>
> I think the bit that Keith tried to highlight is that we should
> always refrain from storing errors.
Keith recommended against storing
On Wed, 16 Dec 2015 15:05:34 +0100
"E.Pasma" wrote:
> 16 dec 2015, Keith Medcalf:
> >> BEGIN;
> >> UPDATE fmtemp SET bal = ROUND(bal,2) + 123.45;
> >> (repeat a 1.000.001 times
> >> END;
> >> SELECT bal FROM fmtemp;
> >> 123450123.45
> >
> > You should NEVER round as you have done above. You
Hi All,
On 12/16/15, Janto Ranjan Paul wrote:
>
> Hi All,
>
> From last couple of days, I am trying to port Sqlite-3.10 database into
> Vxworks...
The latest release version of SQLite is 3.9.2. Are you using
unreleased code from trunk?
--
D. Richard Hipp
drh at sqlite.org
On Wed, Dec 16, 2015 at 9:24 PM, ??? <2004wqg2008 at 163.com> wrote:
> hi,all
>
> There is an interesting phenomenon.As you know, SQLite can retrieve
> records by batch or one by one.
> 1.Retrieve by batch such as sqlite3_get_table.
> 2.Retrieve one by one such as
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