The method I have found works well and efficiently is to surround your
Sqlite accesses with a semaphore and have accessing processes WAIT to
get access to Sqlite. For best performance you would only block when an
INSERT was in progress and let multiple SELECTs run concurrently.
This assumes that all your users go through the same interface so that
they can co-operate.
The alternative is to put busy logic into your Sqlite code, but that is
tedious and cannot be as efficient as synchronising using the more
efficient kernel based method of a semaphore.
Since it is a single file and linked into the application Sqlite is
essentially single user, requiring that only one process at a time
modify the database. It has to use a file lock to enforce that
constraint. If you work with it in your design you can transparently
handle large numbers of users.
As you will already have appreciated, a multi-user Sqlite system must
have short transactions to effectively share access. You might also
look to making users who only read the database be read-only.
In an extreme case you could look to having database INSERTs be handled
by a daemon which would single stream access.
Cesar David Rodas Maldonado wrote:
OK English is not my first language, i am from south America, from Paraguay
so i speak Spanish...
I am doing a project in C multiplataform.. right it project like google, for
a Linux.
the project uses SQ Lite for repository.
The software is a server which listen connection UDP. The server could index
(INSERT) and search within the database (SELECT).
The problem is when i do so much connection at the same time for do index
and search at the same time.
Know is it clear? sorry for my english :D
Thanxs
On 4/3/06, John Stanton <[EMAIL PROTECTED]> wrote:
Try to explain what you are doing. How do you access SQLITE? What
language? What SQL are you using. How many concurrent users do you
have? Are you getting a LOCK error because of multiple users?
Cesar David Rodas Maldonado wrote:
please i need some help
On 4/3/06, Cesar David Rodas Maldonado <[EMAIL PROTECTED]> wrote:
i insert numbers and select numbers, so what could be the solutions,
couse i have to do that
On 4/3/06, Pam Greene < [EMAIL PROTECTED]> wrote:
An INSERT can change the results of your SELECT, so the database has to
be
locked during INSERT. Otherwise, the result of your SELECT would
depend
on
whether the INSERT had finished yet. (The INSERT might even have only
partly finished, which would mean the SELECT was looking at a database
in an
inconsistent state.) It's not good to have unpredictable results like
that.
For more explanation of why what you want isn't a good idea, see any
discussion of an "ACID" database, for example
http://en.wikipedia.org/wiki/ACID .
- Pam
On 4/3/06, Cesar David Rodas Maldonado <[EMAIL PROTECTED]> wrote:
HElp me, couse i just need to do insert and select, i dont use delete
or
replate or update
On 4/3/06, Cesar David Rodas Maldonado <[EMAIL PROTECTED] > wrote:
thanx man
but is posible open several DATABASE with a programm and do
transaccion
without locked the table???
On 4/3/06, Jay Sprenkle < [EMAIL PROTECTED]> wrote:
On 4/3/06, Cesar David Rodas Maldonado < [EMAIL PROTECTED]> wrote:
I have a database.... ok... i do a lot of insert and select, but
there
is
sometime that i cant do the select couse the database is
locked...
i have to do a lot of insert every time, so how can i do for
dont
lock
the
database...
understand guy?
Try this:
http://sqlite.org/lang_transaction.html
