20 replies to this topic

[mdsumner]

I don't want to get off on the wrong foot - I've certainly gotten used to asking questions that try to eliminate the obvious first - so I hope I'm not too caustic - I'm certainly not trying to imply stupidity . . .

Thanks for the welcome!

Again, I can't really discuss Manifold vs. anything else - but I guess the main cause of "general slowness" is due to the explicit import of data, vs. linking to files/database. The reasons for this are interesting and historic and (much) discussed elsewhere . . . but I think saying "it's slow" is just a little inaccurate, and indeed is often due to the use of older versions, or simply poorly designed workflow, and of course sometimes due to "it not being fast enough". The best way to improve this is to carefully identify exactly what datasets, workflows and desired outcomes - and to make sure that there is not some existing "workaround" or different way of approaching the problem.

And, it is not true that you cannot link to external datasets, and the ways in which this can be done are many and are increasing with every release. If the data "should be linked externally", then it's up to the user to actually set up a project that does that.

I don't have a lot of "big dataset" expertise - but for what it's worth, here's the topics I'm aware of that make a big difference to performance:

RAM, temp space, cpu / disk allocation, graphics card

reading the relevant help topics - this can't be understated (but I'm not casting aspersions, I simply don't know)

coordinate precision of datasets - Simplify, Properties/Precision, and Normalize Topology/Metric are relevant help topics

linked external images

creating maps with components all of the same projection - not relying on on-the-fly conversion

Tool/Options-> compress .map files to save space

use of Enterprise Edition for sharing datasets among Manifold projects


Finally - for future interest in Manifold (and to encourage those who might contribute suggestions to the company) I would not be at all surprised if the external database capabilities (along with countless other features) continues to improve and evolve with every release.

[Nick Springer]

So how do I link the data externally?

[mdsumner]

So how do I link the data externally?

<{POST_SNAPBACK}>

What are your data?

Do any of these topics help?


http://69.17.46.170/...ng_drawings.htm

http://69.17.46.170/...ng_surfaces.htm

http://69.17.46.170/...ise_edition.htm

[Nick Springer]

No, I have made Linked Drawings using Queries many times. What I am refering to is the need to embed a large Shape file in the Manifold file. Why can't it just load the data on demand from the Shape file else where on the hard drive? My map files end up being hundreds of megabytes typically.

[mdsumner]

No, I have made Linked Drawings using Queries many times.  What I am refering to is the need to embed a large Shape file in the Manifold file.  Why can't it just load the data on demand from the Shape file else where on the hard drive?  My map files end up being hundreds of megabytes typically.

<{POST_SNAPBACK}>

I guess it comes down to the storage of large datasets in shapefiles, rather than using databases. If you want Manifold to support that then it comes down to it being asked for by users.

BTW, Manifold doesn't store shapefiles in its files. It extracts data from them and stores them natively.

[johnrobot]

I, too, used to need several GIS applications for my projects, but nowadays Manifold GIS has, more or less, replaced all of the others.

Magnus