<HTML dir=ltr><HEAD><TITLE>[Gvsig_english] Question on GeoBD and Metadata when exporting toOracle</TITLE>
<META http-equiv=Content-Type content="text/html; charset=unicode">
<META content="MSHTML 6.00.6000.16890" name=GENERATOR></HEAD>
<BODY text=#000000 bgColor=#ffffff>
<DIV id=idOWAReplyText41022 dir=ltr>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Hello,</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>Ok yes, 0.5 meters is too much. I'll change it to 0.0005 and if I don't see any problem, I think it'll be like that in the upcoming gvSIG 1.9.</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>According to the Oracle documentation, tolerance must be smaller than the smallest hole in polygon layers. I don't think you have a polygon layer with holes whose diameter is less than 0.0005 meters (1/2 mm), do you? ;-)</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>Regards</DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3></FONT> </DIV></DIV>
<DIV id=idSignature17512 dir=ltr>
<DIV><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></DIV>
<DIV>
<DIV><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></DIV></FONT></DIV></FONT></DIV>
<DIV dir=ltr><BR>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>De:</B> Wolfgang Qual [mailto:wolfgang.qual@muenchen.de]<BR><B>Enviado el:</B> jue 24/09/2009 11:53<BR><B>Para:</B> Users and Developers mailing list; Juan Lucas Dominguez Rubio<BR><B>Asunto:</B> Re: [Gvsig_english] Question on GeoBD and Metadata when exporting toOracle<BR></FONT><BR></DIV>
<DIV>Hello Juan Lucas,<BR>thank you very much for this detailed information. I just found out that SDO_TOLERANCE_1 and .._2 are parameters within the ESRI application. Therefore, they refer to SDO_TOLERANCE values for X and Y. According to my colleague, <BR>ESRI sets those values to 0.0005. The tolerance parameter of GeoBD oracle export is set to 0.5 - does that mean that the tolerance is 0.5 meter? Can this be modified? As geometries of the common geodatabase are used in different departments with different applications, tolerance values should be identical, don't you think? Sorry, but I am not that well schooled in this oracle stuff...<BR><BR>Best,<BR>Wolfgang<BR><BR>---8<---<BR>And resolution seems to be available in ESRI-software, too. <BR>Juan Lucas Dominguez Rubio schrieb:
<BLOCKQUOTE cite="" type="cite">
<DIV id=idOWAReplyText8409 dir=ltr>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Hello, Wolfgang.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>When you export a vector layer to Oracle Spatlai/Locator, the sequence of actions is as follows:</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- if a table with the same name exists, it's deleted (dropped in cascade mode). This also removes spatial indices associated with the table</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- the new table is created</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- geometry metadata for this table name is removed (if existed)</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- new geometry metadata is written in USER_SDO_GEOM_METADATA</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- a spatial index on the geometry column is created</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- table records are added (no commits here)</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- a single final commit is performed</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>The tolerance parameter in the metadata is always set to 0.5. Dimension names are set to 'X', 'Y' and 'Z' (if needed) or 'LONGITUDE' and 'LATITUDE'. </FONT><FONT face="Times New Roman" color=#000000 size=3>Max. and min. values for X and Y are set according to the layer's bounding box. Min. and max. values for 'Z' (if needed) are always set to 0 and 100 (this </FONT><FONT face="Times New Roman" color=#000000 size=3>is not very nice, but has no bad effect since the Z value does not currently take part in any geometric operation). Dimension names can be anything you want. You could use 'BREITE' instead of 'LATITUDE', 'EASTING' instead of 'X' or whatever.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>SDO_TOLERANCE_1 and SDO_TOLERANCE_2 refer to tolerance for X and Y perhaps?</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Remember that the tolerance unit is implicit and depends on the table's coordinate system (SRID). If the SRID corresponds to a geodetic coordinate </FONT><FONT face="Times New Roman" color=#000000 size=3>system (latitude, longitude), then the tolerance is assumed to be expressed in meters. If the SRID corresponds to a projected coordinate system (such </FONT><FONT face="Times New Roman" color=#000000 size=3>as the German EPSG:3146X series) then the tolerance is assumed to be expressed in the same unit used by the coordinate system (usually meters). </FONT><FONT face="Times New Roman" color=#000000 size=3>This also applies if the SRID is NULL. According to this, it would be a bad idea to have a table with geometries whose vertices are in latitude and </FONT><FONT face="Times New Roman" color=#000000 size=3>longitude and setting the SRID to NULL, because the tolerance (0.5) would correspond to a few dozens of kilometers.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>The tolerance settings are very unlikely to have any effect when you work with gvSIG because the application checks again the true relationship </FONT><FONT face="Times New Roman" color=#000000 size=3>between geometries after they have been converted to the gvSIG geometry model. In other words: the 'select by rectangle' tool should not behave in a </FONT><FONT face="Times New Roman" color=#000000 size=3>strange way even if you have a bad tolerance value. Of course you will see the effects of a bad tolerance value from other applications or when you </FONT><FONT face="Times New Roman" color=#000000 size=3>execute a SQL statement directly against your database.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>So the metadata stored for a Oracle Spatial/Locator table are:</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- Owner</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- Table name</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- Geometry column name (the metadata record will be replicated for several values because a table can have more than one geometry column)</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- Dimension info (for each dimension: dimension name, max value, min value, tolerance)</FONT></DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>- SRID (possibly NULL)</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>If you have a 3D vector layer (for example a 3D shapefile) I think you will not notice the third dimension while you work with views and layouts, but if you </FONT><FONT face="Times New Roman" color=#000000 size=3>export that layer to your Oracle Spatial/Locator database, it will be stored with a 3D geometry column (you can see the number of dimensions of each </FONT><FONT face="Times New Roman" color=#000000 size=3>using Sqldeveloper for example)</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>As you perhaps know, Oracle Spatial/Locator supports 4D geometries (XYZT, I think Oracle normally uses the letter T instead of M for the 4th </FONT><FONT face="Times New Roman" color=#000000 size=3>dimension). When you open one of these tables with gvSIG, the resulting layer is a 3D layer (4th dimension is discarded)</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>I have never heard about a parameter called resolution in the table metadata. Perhaps you are talking about some operations that allow you to restrict </FONT><FONT face="Times New Roman" color=#000000 size=3>the result by setting a min and max_resolution value, but this is not connected to tables' metadata.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>I agree that it would be a good idea to let the user set the metadata values.</FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Regards,</FONT></DIV>
<DIV dir=ltr><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV></DIV>
<DIV id=idSignature43918 dir=ltr>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></FONT></FONT></DIV>
<DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></FONT></FONT></DIV></DIV></DIV>
<DIV dir=ltr><BR>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>De:</B> <A class=moz-txt-link-abbreviated href="mailto:gvsig_internacional-bounces@listserv.gva.es">gvsig_internacional-bounces@listserv.gva.es</A> en nombre de Wolfgang Qual<BR><B>Enviado el:</B> jue 24/09/2009 8:59<BR><B>Para:</B> Users and Developers mailing list<BR><B>Asunto:</B> [Gvsig_english] Question on GeoBD and Metadata when exporting toOracle<BR></FONT><BR></DIV>
<DIV>
<P><FONT size=2>Hi list,<BR>in our City administration, different GIS software is used to work with<BR>spatial data. Among them, ArcMap and gvSIG allow to access a central<BR>oracle spatial database. Thanks to the great GeoBD extension, accessing<BR>that database via gvSIG is very comfortable, even exporting new layers<BR>to the database is possible.<BR>Yesterday, a colleague of mine who is in charge of the overall design of<BR>the geodatabase asked me to provide some details on GeoBD's<BR>capabilities. He asked me about metadata that is created by that<BR>extension when exporting a shapefile to the oracle spatial database and<BR>possibilities to set custom settings for the metadata. In this context,<BR>he also talked about "tolerance" (SDO_TOLERANCE_1, SDO_TOLERANCE_2),<BR>"resolution". I have no idea, whether GeoBD sets these values.<BR>Therefore, I would be very happy, if someone of you (maybe the<BR>developers from Prodevelop) could give me some details on the type and<BR>values of metadata that is written to new oracle spatial layers. That<BR>would be very great to have.<BR><BR>Best regards and thank you very much for your help.<BR>Wolfgang<BR><BR>--<BR>Wolfgang Qual<BR>Landeshauptstadt München<BR>Referat für Gesundheit und Umwelt<BR>RGU-UW 11<BR>Sg. 1 Gesundheits- und Umweltberichterstattung,<BR>Energie und Klimaschutz<BR>Bayerstr. 28a, 80335 München<BR>Tel.: +49 (0)89 233-477 17<BR>Fax.: +49 (0)89 233-477 05<BR>E-Mail: <A class=moz-txt-link-abbreviated href="mailto:wolfgang.qual@muenchen.de">wolfgang.qual@muenchen.de</A><BR><BR>_______________________________________________<BR>Gvsig_internacional mailing list<BR><A class=moz-txt-link-abbreviated href="mailto:Gvsig_internacional@listserv.gva.es">Gvsig_internacional@listserv.gva.es</A><BR><A href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A><BR></FONT></P></DIV><PRE><HR width="90%" SIZE=4>
_______________________________________________
Gvsig_internacional mailing list
<A class=moz-txt-link-abbreviated href="mailto:Gvsig_internacional@listserv.gva.es">Gvsig_internacional@listserv.gva.es</A>
<A class=moz-txt-link-freetext href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A>
</PRE></BLOCKQUOTE><BR><BR><PRE class=moz-signature cols="72">--
Wolfgang Qual
Landeshauptstadt München
Referat für Gesundheit und Umwelt
RGU-UW 11
Sg. 1 Gesundheits- und Umweltberichterstattung,
Energie und Klimaschutz
Bayerstr. 28a, 80335 München
Tel.: +49 (0)89 233-477 17
Fax.: +49 (0)89 233-477 05
E-Mail: <A class=moz-txt-link-abbreviated href="mailto:wolfgang.qual@muenchen.de">wolfgang.qual@muenchen.de</A> </PRE></DIV></BODY></HTML>