В сообщении от Thursday 19 June 2008 00:22:37 Dennis Cote написал(а):
> Alexey Pechnikov wrote:
> > I'm replicating my database using sqlite dump and load or sql queries.
> > I'm not sure that rowid is not different after that.
>
> If you assign each row an id (and even better make it an integer primary
> key) and use those id columns to link related records then all your
> links will survive across a dump and reload sequence.
>
> However, that shouldn't matter for the a single session with a loaded
> database. Your "other question" is returning timestamp based on some
> criteria, it could simply return a rowid instead of a timestamp. The
> rowid is valid for the entire session with the database.
>
> > Can I do it from tcl? And how use index?
>
> I'm not sure how you handle floating point values in TCL since it is
> typeless. It may not be possible to avoid the conversions. This is even
> more reason to use ranges to locate records by time, and rowids to
> locate specific records.
I have same database on host A and host B. On _both_ hosts I can
insert/update/delete/select rows and periodically synchronize databases.
CREATE TABLE photos
(
name TEXT NOT NULL,
filename TEXT NOT NULL,
hostname TEXT NOT NULL DEFAULT 'A',
save_date REAL COLLATE BINARY,
update_date REAL COLLATE BINARY,
delete_date REAL COLLATE BINARY
);
CREATE TRIGGER photos_delete before delete on photos begin
update photos set delete_date = julianday('now') where rowid=old.rowid and
delete_date IS NULL;
select RAISE (IGNORE);
end;
CREATE TRIGGER photos_insert after insert on photos begin
update photos set save_date = coalesce(save_date, julianday('now')) where
rowid=new.rowid;
end;
CREATE TRIGGER photos_update after update on photos begin
update photos set update_date = julianday('now') where rowid=old.rowid;
end;
For replication I can select all rows updated by selected period and send it
to other hosts.
ROWID can duplicate on host A and host B for different rows. But the chances
of timestamp unique are good. So, I select item by save_date form host A or
host B equally.
P.S. Yes, multy-master replication is very complex but very helpfull... I try
use simple way. Are exists any better choices?
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