Month: July 2020

The SDO_AGGR_CONCAT_LINES function in Oracle 10g and above allows for linestrings to be concatenated via GROUP BY SQL clauses. However, this function is only available for Spatial users on Enterprise Edition of the Oracle database 10g (it can be used on 11g). Locator users can, however, use the mdsys.sdo_util.concat_lines function to append two linestrings together.Read More

I had occasion to convert a set of 5 vertex polygons that defined grid squares to their optimized rectangle equivalent. To do this I created a simple function as follows. Which can then used as follows: Update On the basis of the excellent comments made by Farid Cheraghi, I have included his rectangle check (whichRead More

I was asked the other day how to create a square buffer around a linestring (or set of linestrings). If you used my parallel function, then everything could be achieved as follows: Putting a PL/SQL function wrapper around this is trivial. I hope this helps someone.

Like many others out there, I often have a need to convert a decimal seconds value to its canonical equivalent as a string. Which this can be done using standard SQL I prefer to wrap the required conversion functions inside a function as follows. Which can be called as follows: HMS 3:43:33 3h43m33s I hopeRead More

I have been doing a lot of work recently with processing the errors reported by Oracle’s MDSYS.SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT function. The results that are output from this function are not well documented with some outputs only being discovered by having bad geometries that generate those errors! But it was interesting for me to note that the functionRead More

The SDO_LENGTH function within SDO_GEOM package can be called with an optional unit parameter as in the following call signature: But what are a valid list of values for the unit parameter? For a start, if the SDO_GEOMETRY has a NULL SDO_SRID value then the unit parameter can’t be used at all! For other cases,Read More