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Aug
15
comment QGIS Spatialite tabular updates are very slow
One thing I would try first, is check page_size and cache_size are reasonably set. There's a nice write up at gaia-gis.it/gaia-sins/spatialite-cookbook/html/system.html
Aug
11
comment How do I optimise performance on a local QGIS + PostGIS installation?
You can also hit cancel when the little window pops up showing how many records it's counted before the attribute table pops up.
Aug
11
comment How do I optimise performance on a local QGIS + PostGIS installation?
The slow attribute table loading is another issue that might have to be filed as either a bug or enhancement request for QGIS to allow quick loading of attribute tables wtih lots of records.
Aug
11
comment How do I optimise performance on a local QGIS + PostGIS installation?
Clustering won't make a difference unless your tables have been "partitioned" to exist on more than one hard-drive/partition. Indexes on the columns being used in any queries would speed up those queries considerably.
Aug
11
comment How do I optimise performance on a local QGIS + PostGIS installation?
It's a little difficult to troubleshoot ATM. Some details about your postgresql.conf would help to see if there's been any attempts to optimize there. Do you have any indexes generated for the columns you want to use for querying/subsetting? Sometimes it helps if you place a checkmark for the Use estimated table metadata option when making a new PostGIS connection (or edit an existing one) inside QGIS. After adding the large shapefile into the database did you get a chance to run VACCUM ANALYZE; or REINDEX;?
Aug
10
comment 64 Bit Win 8.1 grass 7 missing dependency
@markusN It looks like his 64 bit version is working too, but the error is just the missing dependency for grass 7 from Processing - which is strange because grass7 is installed. So there's a bug report for Processing at hub.qgis.org/issues/13072 and a fix may be in master github.com/qgis/QGIS/commit/…
Aug
6
comment Selecting entities based on first character of the attribute field being letter using QGIS?
Would be nice if the query box (for subsetting) supported reg expressions too, but was more flexible and could make use of reg exp operators.
Aug
5
awarded  Nice Answer
Jul
20
comment QGIS Processing Scripts Shared Code
@spencerrecneps No it won't, but it does show you the list of paths that are part of the PYTHONPATH.
Jul
20
answered QGIS Processing Scripts Shared Code
Jul
11
comment Starting animation after X seconds in OpenLayers 3?
sounds like a possible bug report, if it's a function that's not working as it's supposed to =)
Jul
9
comment Inverted shading with polygons in QGIS 2.8
@corvus I would probably just build a .vrt of the files and layers I need, then apply the inverted effect to the vrt layer.
Jul
9
answered Inverted shading with polygons in QGIS 2.8
Jul
9
comment How to select features containing specific text string using an expression in QGIS
@chris You can use that same query in other parts of QGIS like as a definition query or styled using rule based rendering - really depends on the reason why you need to apply the query (ie, analysis, visualization, exporting, etc). Selections are a bit intensive but if applied as a definition query then it only displays those features in the query on the canvas or makes them available for processing. Essentially what you did when copy/pasting the selection as a new vector layer.
Jul
8
comment How to select features containing specific text string using an expression in QGIS
@bugmenot123 There might be a number of things that can make it slow, but for the most part it's fast especially if there is an index on the field you're querying. Speed of the query often depends on data format, management and storage.
Jul
8
answered How to select features containing specific text string using an expression in QGIS
Jun
28
comment Calculate normalized summary
Glad to help, but this site really like new questions to be posted individually so if you've found it hasn't been answered already, ask it =)
Jun
28
comment Loading .shp file into QGIS gives error message
Maybe even try dragging and dropping just the .shp file into QGIS to see if it loads properly. If it doesn't there could be some missing shapefile parts like underdark says or something else going on.
Jun
25
comment Calculate normalized summary
If they are relative to the area in a discrete way, then it might be as simple as summing the values per var2,3,4 column during the dissolve.
Jun
25
comment Calculate normalized summary
It's still a little difficult to understand because if you dissolve by var1 the SHAPE_area/SHAPE_length field will be updated automatically if it's a feature class in a filegeodatabase. That's the first step... But I think we need some clarity on the rationale used to populate var2,3 and 4. Sounds like that should be done after the dissolve based on a field calculation. It might be helpful if you can explain how you came up with var2,3 and 4 in the first place.