[GRASS-user] v.color takes a long time for 2E6 records

GRASS GRASS user
1

Hi Everyone,

When using v.color on a map with 2 Million points, it takes more than 24 hours (I guess the last time it took near 40 hours). The CPU is busy less than 20% on a 8 core machine and a lot of memory is available (50% at least is empty out of the 16 GB). Is there a way that I could accelerate the processing? Is it normal at all?

Here is the command I am using:

v.colors -c --verbose map=WM195@Waterlix use=attr column=BRProbH color=gyr rgb_column=ColorH

Thanks for your help in advance,

Mehrdad

···

Mehrdad Varedi

2

On Wed, May 30, 2018 at 11:50 PM, Mehrdad Varedi <varedi@gmail.com> wrote:

Hi Everyone,

When using v.color on a map with 2 Million points, it takes more than 24 hours (I guess the last time it took near 40 hours). The CPU is busy less than 20% on a 8 core machine and a lot of memory is available (50% at least is empty out of the 16 GB). Is there a way that I could accelerate the processing? Is it normal at all?

A reason could be that the vector uses dbf as database driver. Database drivers other than dbf can make use of an index, therefore you could verify the database driver for WM195 with v.db.connect -p

If the vector uses dbf, you can switch to the default sqlite driver with

db.connect -d

then verify with db.connect -p

now make a copy of the vector and try again v.colors.

HTH,

Markus M

Here is the command I am using:

v.colors -c --verbose map=WM195@Waterlix use=attr column=BRProbH color=gyr rgb_column=ColorH

Thanks for your help in advance,

Mehrdad

–
Mehrdad Varedi

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https://lists.osgeo.org/mailman/listinfo/grass-user

3

Hi Markus,

I tried the db.connect -p and found that the database driver is SQLite.

(Thu May 31 10:53:07 2018)
db.connect -p
driver: sqlite
database: F:\Projects-Analysis\GRASSData\SWOntarioTestSites\Waterlix\sqlite\sqlite.db
schema:
group:
(Thu May 31 10:53:07 2018) Command finished (0 sec)

Does anything else cause the issue?

Thanks for your help.

Mehrdad

···

On Thu, May 31, 2018 at 9:13 AM, Markus Metz <markus.metz.giswork@gmail.com> wrote:

On Wed, May 30, 2018 at 11:50 PM, Mehrdad Varedi <varedi@gmail.com> wrote:

Hi Everyone,

When using v.color on a map with 2 Million points, it takes more than 24 hours (I guess the last time it took near 40 hours). The CPU is busy less than 20% on a 8 core machine and a lot of memory is available (50% at least is empty out of the 16 GB). Is there a way that I could accelerate the processing? Is it normal at all?

A reason could be that the vector uses dbf as database driver. Database drivers other than dbf can make use of an index, therefore you could verify the database driver for WM195 with v.db.connect -p

If the vector uses dbf, you can switch to the default sqlite driver with

db.connect -d

then verify with db.connect -p

now make a copy of the vector and try again v.colors.

HTH,

Markus M

Here is the command I am using:

v.colors -c --verbose map=WM195@Waterlix use=attr column=BRProbH color=gyr rgb_column=ColorH

Thanks for your help in advance,

Mehrdad

–
Mehrdad Varedi

grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user

–

Mehrdad Varedi