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1

For this type of generic question regarding server "specs" for ESRI solutions, the most authoritative and comprehensive documentation can be found on ESRI's "System Design Strategies" Wiki pages: http://wiki.gis.com/wiki/index.php/System_Design_Strategies_Preface


1

To answer your question, the way it works is that the database will return one row for each of the distinct values, but there is no guarantee that every time you use the layer the same rows are returned. What row it latches onto is somewhat arbitrary, especially if people are editing the table in question. Alternatives to the unique identifier that is not ...


0

You can run every vaild SQL-statement by setting up a QgsDataSourceURI (with your database connection) and parse the statement in quotes to "aTable" parameter instead of a table name. Notice: geometry-column and primary key have to be set! In your case, try something like: uri = QgsDataSourceURI() uri.setConnection('hostname', 'port', 'dbName', 'username', ...


5

I think you're misunderstanding the purpose of the unique identifier field, and using in ways that will generate undefined results. When a Query Layer is defined, you are given a great deal of leeway to generate an SQL query. ArcGIS uses that query, with various constraints, to access the data. The most common constraint is a spatial filter clause (using ...


2

Use Spatialite Database! It is a lightweight file based spatial DB supported out of the box by QGIS. First set-up a spatialite DB following theses instructions Push your two tables to this spatialite DB using QGIS DB manager Assuming that your tables are called "polygon" and "line" run the following SQL command in DB manager query interface. SELECT ...


2

The ST_ClusterWithin and ST_ClusterIntersecting functions in PostGIS first collect all input geometries into a Postgres array before doing their processing. Since the size of this array is proving to be a limitation, you can process this dataset only if you can reduce the total size of this array. Some options for doing this: Use a GROUP BY clause to ...


2

So we have a definite answer to the question: The problem involves QGIS not liking the backslash try this replace ("Hotlink" , 'ABCD' , 'Maps\\ABCD\\ABCD') see esdm.co.uk/qgis-field-calculator-backslash-gotcha


2

Once you have your features selected, you have two options: Run Summary Statistics on the "numeric column" which will return the min, max, average, and other statistical measures on said column. If you're manually iterating through the subsets of points, this is easy: open the attribute table, right click on the column heading and select "Statistics". If ...


2

I would try doing this using the Select (Analysis) tool: Extracts features from an input feature class or input feature layer, typically using a select or Structured Query Language (SQL) expression and stores them in an output feature class. in batch mode: To use batch, right-click a tool and click Batch. This opens the batch dialog box with ...


0

An easy way of adding PostGIS data to ArcMap is by adding an 'Interoperability Connection'. To do this, the 'Data Interoperability Extension' is required. It's considered a good idea to add a 'Numeric Index' and 'Primary Key' to the PostGIS Database Table before creating the connection.


0

Conceptually, nothing. A JOIN simply pairs up rows based on whether a condition is true. In a spatial join, the condition is just a geometric operation on geometric data (e.g., two polygons must intersect). The reason a big deal is made of it is that spatial data is considerably more complex than other typical data types. This makes it more difficult to ...


2

The problem is that SQL view in geoserver doesn't allow to use semicolon(';') in SQL statement. Geoserver only allows one query statement. You didn't provide the structure of Your database, but may be it's possible to build SELECT query with subquery and get the same result.


4

This technique will work in versions of PostGIS < 2.2.0. Create cluster polygons by buffering the points by half your cluster distance, assign a cluster ID, then transfer the cluster ID to the points the polygons intersect: --Buffer all points by the half the cluster distance (in this case 40 metres), --merge into a multipolygon using st_union(), --then ...


5

If you can updgrade to postgis 2.2.0 you might be lucky because that feature has just been introduced. From the doc: "ST_ClusterWithin is an aggregate function that returns an array of GeometryCollections, where each GeometryCollection represents a set of geometries separated by no more than the specified distance." Check this: ...


3

I have a feeling you may be over complicating the sql a bit. The following sql should sort out your problem and give you the answer you are looking for. UPDATE schema1.table1 SET column1 = column2 FROM schema2.table2 WHERE ST_Intersects(table1.geom, table2.geom);


3

The "read_only" table obviously needs some input, as I could not find anything in the cookbook, after some search I found this insightful discussion with mr. furieri himself: https://groups.google.com/forum/#!topic/spatialite-users/n8l977RL9-0 conclusion: 1 = TRUE = ReadOnly View (unsupported write ops) 0 = FALSE = Not ReadOnly, thus Writable View So ...


0

To select a single feature class from a gdb, we query for all entities inside it: -sql "select * from FEATURE_CLASS_NAME" To generate a list of feature classes following your sample use nested FOR loops: @echo off for %%S in (01 02 03) do ( for %%F in (01 02 03) do ( echo ogr2ogr out.gdb in.gdb -sql "select * from Sec%%S_Frm%%F" ) ...


0

This may not be the fastest solution... But I usually just cheat by joining all the features of the other table. Create table blah as select d.* from data_i_want d, (select st_union(geom) geom from not_in_here) n where st_disjoint(d.geom,n.geom); Nice and snappy if the not_in_here table isn't that complex.


2

I realize this is an old post, but for anyone else that comes across it. If you don't know how your input file is (shapefile, geodatabase, or file geodatabase) there is a function that will append the field delimiters ([ or ") depending on the input featureclass. See ...


3

Just to add to the already given great answers, you could also use the Select by location tool from the Processing Toolbox to give you more options on how you want to select your objects:



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