topic Re: Time for st_AsText for complex features in Geodatabase Questions

Time for st_AsText for complex features

ModyBuchbinder — Wed, 21 Oct 2020 13:25:16 GMT

Hello all

We are trying to translate some geometries in Oracle to WKT using st_AsText

It takes a long tome for complex features.

For example a polygon with 31k points was translated into 600k WKT string in 25 seconds.

Does this reasonable time? Is there any tuning in the database or Geodatabase that can make this faster?

Thanks

Re: Time for st_AsText for complex features

George_Thompson — Wed, 21 Oct 2020 15:41:36 GMT

You may want to work with Technical Support on this issue to help determine where the bottle neck may be.

What is the version of Oracle (include the O/S that it is on) and the version that the Geodatabase it at?

What happens when the polygon has less or more vertexes? Is the performance different.

Re: Time for st_AsText for complex features

ModyBuchbinder — Thu, 22 Oct 2020 04:14:39 GMT

Hi George

Thanks for the response.

Technical support might say this is ok so I first need to understand if it is reasonable.

I hope if somebody has a polygon with more then 10k vertexes they can test it in 3 minutes.

It is a Linux (Red Hut) machine that runs Geodatabase 10.7.1

The time is changing by the polygon (not sure if it is linear). This is just some countries borders but very detailed.

The border of Russia have many more vertexes and takes for ever.

Thanks

Re: Time for st_AsText for complex features

VinceAngelo — Tue, 24 Nov 2020 03:08:51 GMT

Unfortunately, that performance is about what I've seen (it's truly awful with 6.1M vertices). I did some benchmarking, and found I could improve performance by 40-60 percent *and* reduce the size of the resulting string by 20-30%, but only by using 'C' language functions at the lowest level of the component libraries. The fix would require rewriting the low-level WKT function.

- V