I hadn't really thought of deliberately inserting a bad geometric. So,
I just tried it:
insert into ml_polygon (msg_no, rev_no, geom) values (-1, -1,
ST_SetSRID('POLYGON((-90.869358 38.839444,-90.869358
38.839447,-90.869358 38.839444))', 4269));
select msg_no, rev_no, st_npoints(geom) from ml_polygon where msg_no = -1;
msg_no | rev_no | st_npoints
--------+--------+------------
-1 | -1 | 3
Then on node 2:
select msg_no, rev_no, st_npoints(geom) from ml_polygon where msg_no = -1;
msg_no | rev_no | st_npoints
--------+--------+------------
-1 | -1 | 3
(1 row)
select msg_no, rev_no, st_astext(geom) from ml_polygon where msg_no = -1;
ERROR: geometry requires more points
So, slony copied the insert over.
So, I tried a delete:
delete from ml_polygon where msg_no = -1;
DELETE 1
MO=> commit;
COMMIT
MO=> select msg_no, rev_no, st_npoints(geom) from ml_polygon where
msg_no = -1;
msg_no | rev_no | st_npoints
--------+--------+------------
(0 rows)
And on node 2:
select msg_no, rev_no, st_npoints(geom) from ml_polygon where msg_no = -1;
msg_no | rev_no | st_npoints
--------+--------+------------
(0 rows)
This makes me slightly less concerned about the data. I do not do
updates of this table. The only reason I was doing an update here was
to "fix" the bad geometrics.
Still not sure why the original update didn't work though....
- B
On 03/23/2012 11:10 AM, Paul Ramsey wrote:
On Fri, Mar 23, 2012 at 6:18 AM, Brian Peschel<[email protected]> wrote:
Figured I would start here since I suspect this is a PostGIS problem more
than a Slon problem.
My main node is a Fedora 8, Postgres 8.3.1, Slon 1.2.20, and PostGIS 1.3.
This is being replicated via slon to an Ubuntu 10, Postgres 8.4.11, Slon
1.2.20, and PostGIS 1.4. My table looks like this:
Table "public.ml_polygon"
Column | Type | Modifiers
--------+----------+-----------
msg_no | integer | not null
rev_no | integer | not null
geom | geometry |
Indexes:
"ml_polygon_pkey" PRIMARY KEY, btree (msg_no, rev_no)
"ml_geom_idx" gist (geom)
Check constraints:
"enforce_dims_geom" CHECK (ndims(geom) = 2)
"enforce_srid_geom" CHECK (srid(geom) = 4269)
I have some bad geoms in the database, basically polygons with invalid point
counts:
70650590 | 1 | POLYGON((-90.869358 38.839444,-90.869358
38.839447,-90.869358 38.839444))
In PostGIS 1.3, this is perfectly acceptable (even though it is bad). In
1.4, this doesn't work and a select gives you this error:
ERROR: geometry requires more points
which also appears in my Postgres log. Google tells me this was an issue
with early PostGIS 1.4 versions. Okay.
But I need to fix these. So on my main node, I did this:
update ml_polygon set geom = ST_SetSRID('POLYGON((-90.869358
38.839444,-90.869358 38.839447,-90.869358 38.839447,-90.869358 38.839444))',
4269) where msg_no = 70650590 and rev_no = 1;
which happily updated my main node. And nothing showed up on by second
node. No errors messages anywhere I could find. New inserts in this table
in my main node showed up on the second node, so I know slony is working,
but this update never showed up.
I did a different update (to an existing 16 point polygon) and the updated
showed up in my second node. I was worried that slony wouldn't pick up
updates of a geometry column, but this proved to me that wasn't the problem.
I re-did the first insert and, surprise, surprise, it worked fine.
So, I tried a different record with the same 3 point problem, and it showed
up on the second node.
Needless to say, I am very confused. Not only is the constancy of what
works and fails a problem, but the fact the slony copy (apparently) failed
with no error messages concerned me also. Can I trust the data in my second
node?
Based on the description I would think not. If you insert another new
bad geometry in the master, does it show up on the slave? If the bad
geometries can't traverse from 1.3 to 1.4 you'll have a systemic chunk
of missing data.
Any thoughts?
- Brian
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
--
Brian Peschel
One Call Concepts, Inc
Systems Division
Voice: 414-259-1047 ext. 93
Fax: 414-777-3666
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
