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[SQLite] C library embeddable DB .

Janko
30-Apr-2009
[1029x2]
(I tried rebDB on same VPS - localy where comp. is fast I notice 
no delay at sqlite either)
and this is no problem with rebol binding as the delays are the same 
if I go to sqlite3 shell
Pekr
30-Apr-2009
[1031]
Have you tried put BEGIN transaction and END transaction outer commands? 
Because if not, then it commits each time. The difference is going 
to be ... well, drastic ...
Janko
30-Apr-2009
[1032]
yes, I know for that .. that would come into play if I would be doing 
10 inserts for example ,.. with begin commit it would take just 1/10 
of time as without , but I am doing a simple sql scentence here. 
and I tried begin/commit also with this.
Pekr
30-Apr-2009
[1033]
ah, single query?
Janko
30-Apr-2009
[1034]
yes, and nothing big.. 5 simple rows
Pekr
30-Apr-2009
[1035]
show me the table structure, show me the query :-)
Janko
30-Apr-2009
[1036x2]
I talked about this in detail a while ago.. now I optimised the problem 
so it's not a biggie any more but I am still mad that all rebol files 
can do changes in moments and when I need to update the sqlite page 
halts for noricable time
any query I try :) .. I talked about this to you already :) .. look 
a little up at 14-Apr
Pekr
30-Apr-2009
[1038]
Janko - I did small test for you. With no indices the speed was: 
0:00:00.516 and I used LIKE expressions, which need to do searches 
in terms of field values .... 

REBOL []

print "Starting test for Janko ..."

do %sqlite.r

attempt [delete %janko.db]

connect/direct/create %janko.db

sql {
CREATE TABLE [domains] (
[id] INTEGER  NOT NULL PRIMARY KEY,
[domain] VARCHAR  NOT NULL,
[user] VARCHAR  NOT NULL,
[processed] DATETIME  NULL,
[ok_count] INT NOT NULL DEFAULT 0,
[fail_count] INT NOT NULL DEFAULT 0,
[error] TEXT NULL
)

}

sql "BEGIN"

for i 1 1000 1 [

 sql reduce ["insert into domains values(?,?,?,?,?,?,?)" i i i i i 
 i i]
]

sql "COMMIT"

start: now/time/precise


sql {update domains set user = 'u3' where domain like '%1%' and user 
like '%1%'}

print now/time/precise - start

disconnect %janko.db

halt
Janko
30-Apr-2009
[1039x2]
hm... mucho interesante :)
I will try this on my local computers and then on that VPS.. and 
report you back :)
Pekr
30-Apr-2009
[1041]
btw - what is VPS?
Janko
30-Apr-2009
[1042x2]
virtual private server ... like you can buy here .. www.linode.com 
or sliceshare.com
it's like you have your own computer that you can reinstall stuff 
or OS .. separated from others but it's running on virtualisation 
software so there are many such separate computers per one real computer 
, so it's *cheaper* than paying for having a full server
Pekr
30-Apr-2009
[1044]
ah, virtual machine, ok ...
Janko
30-Apr-2009
[1045x2]
you can put cheyenne there or any other custom server you want
yes
Janko
9-May-2009
[1047x4]
hm.. I have a question for SQL / sqlite experts : 

I have a query with two JOINS . There is parent table which has 2 
subtables ... in each subtable I need to aggregate (SUM) some value 
... 


select i.*, SUM(ib.price * ib.qty) as amount, SUM(ip.amount) as payed_amount
	from invoice_sent as i 

  left outer join invoice_sent_b as ib on i.id = ib.id_invoice_sent

  left outer join invoice_sent_p as ip on i.id = ip.id_invoice_sent
	group by i.id order by i.title;


The problem is tha because of join , the amount is correct , is the 
sum of values in invoice_sent_b , but payed_amount is multiplied 
by the number of rows invoice_sent_b has . 


I understand why this happens, but I don't know how to prevent it, 
if I want to get all data in one query.


( I know how to solve the prolem , but it's outside the DB so it's 
more of  a hack  -- I also ger COUNT of _b table rows and divide 
second SUM by it on client )
ah, my method with count won't work because count also multiplies 
if I have more than 1 columnt in second subtable
This guy has totally the same problem but no answer http://forums.devshed.com/db2-development-114/left-outer-join-3-tables-sum-field-of-2nd-3rdt-588801.html
found solution. I need to join with subqueries:

				{SELECT * FROM } table { as i 
					LEFT OUTER JOIN
					( 

      SELECT id_} table { as ibs_paren, SUM(price * qty) as amount 
							FROM } table {_b ib
							GROUP BY id_} table {
					) ibs ON i.id = ibs_paren
					LEFT OUTER JOIN
					(

      SELECT id_} table { as ips_paren, SUM(ip.amount) as payed_amount 
							FROM } table {_p ip
							GROUP BY ip.id_} table {
					) ips ON i.id = ips_paren
				order by title;
Chris
21-May-2009
[1051x3]
Has anyone done any benchmarks for running scripts from a DB instead 
of from the filesystem?
Say, where there are a moderate number of moderate sized scripts 
- could it be quicker just to fire up an SQLite connection and access 
the scripts/modules from records as opposed to flat file?
Perhaps particularly a CGI environment where each instance is a separate 
process?
Janko
21-May-2009
[1054]
If you had persistent connection and if sqlite does some caching 
it could be faster, but if you need to open a connection on each 
request I think it would be much slower because that is more expensive 
(I assume).. it probably also matters how many scripts do you need 
to run per request
Gregg
21-May-2009
[1055x2]
The OS caches things too, don't forget.
It shouldn't be hard to devise a small benchmark though.
RobertS
22-May-2009
[1057]
.
amacleod
26-May-2009
[1058]
I seem to get an error with sqlite after using "call" to start an 
external program.

** User Error: SQLite out of memory
** Near: make error! reform ["SQLite" error]

Anyone experience this?
Janko
26-May-2009
[1059]
Check if you have the right path to file.. and make it an absolute 
path.. and if you have the right version .. sqlite != sqlite3
amacleod
26-May-2009
[1060]
It works fine until I try to call another app. Paths do not change 
but I'm not using absolute paths. I'll need to test that...
Janko
26-May-2009
[1061]
I got similar error but I don't know if it was for the relative path 
or not the right version of dll / so
amacleod
26-May-2009
[1062]
I changed all the paths to absolute paths...it seems to have done 
the trick. Thanks for the hint, Janko!
Janko
26-May-2009
[1063]
youre welcome
jack-ort
10-Sep-2009
[1064x2]
I apologize if this is a repeat of an earlier message - I thought 
I submitted, but never saw it appear.


Question: With REBOL/View 2.7.6 under Windows XP, using SQLite driver 
v1.0.6, should I be able to use the concatenate operator (||) in 
a SELECT statement?  Query works under the sqlite3 command line, 
and a similar SELECT without the concatenate returns values as expected:

>> sql "select jobid, role from roles where userid = 'cda6'"
== [[1124 prgr] [1125 test]]

>> sql "select jobid || role from roles where userid = 'cda6'"
** Syntax Error: Invalid integer -- 1124prgr
** Near: (line 1) 1124prgr
>>
Reversing the column order in my concatenate makes it work, but not 
what I want:

>> sql "select role || jobid from roles where userid = 'cda6'"
== [[prgr1124] [test1125]]
>>
ManuM
11-Sep-2009
[1066]
Try this >>sql "select '' || jobid || role from roles where userid 
= 'cda6'"

I think the problem is the first column is a integer, so SQLite driver 
think the result is a integer ( invalid integer ), with '' the first 
column is a string
jack-ort
11-Sep-2009
[1067]
Thanks for the suggestion Manu.  Sounded good to me, but I get the 
same error even with the empty string at the front:


>> sql "select '' || jobid || role from roles where userid = 'cda6'"
** Syntax Error: Invalid integer -- 1124prgr
** Near: (line 1) 1124prgr
>>


even though it appears to be integer, jobid variable is text, according 
to SQLite:
>> sql "select typeof(jobid) from roles"
== [[text] [text] [text] [text]]
>>
Again, thanks!  I welcome any other suggestions.
Robert
11-Sep-2009
[1068]
Why not make the JOIN on the Rebol side?
ManuM
11-Sep-2009
[1069]
Jack, finally I saw the problem


The return of sql isn't two blocks of string, it's two blocks of 
word. So 1124prgr isn,t a valid word and isn't a valid integer

>> a: sql "select jobid, role from roles where userid = 'cda6'"
>> type? first first a
==word


You need to add the /direct refinement to sql and it returns strings

>> sql/direct "select jobid || role from roles where userid = 'cda6'" 
==[["1124prgr"]["1125 test"]]
jack-ort
14-Sep-2009
[1070]
Robert - thanks...that's what I eventually did.


Manu - thank you for making clear what the /direct refinement does...I 
had read about that in the SQLite Driver Guide, didn't understand 
it since REBOL is still new to me, and forgot about it.  Works perfectly! 
 So much to learn....
jack-ort
15-Sep-2009
[1071]
Is there a problem with:

http://www.dobeash.com/

seems like domain is up for sale ??
Graham
15-Sep-2009
[1072]
Probably hasn't paid renewal fees!
GiuseppeC
7-Oct-2009
[1073x2]
It is back online again.
Does REBOL SQLite support SQLLite3 ?
Pekr
7-Oct-2009
[1075]
yes, it does ...
jrichards
23-Nov-2009
[1076]
Is it possible to use the sqlite driver for a file that resides on 
the internet?
Robert
24-Nov-2009
[1077]
As long as you can access it via a normal file-path, yes. Can be 
slow but should work.
Janko
24-Nov-2009
[1078]
stupid me, I only now realized sqlite driver supports prepared statements 
too and I was concatenating strings all along.