I have a conceptual question on Vertica Projection. Why it is not allowed to put a filter in a projection ? My intention of asking this question is - I have a requirement where I need to dynamically access data from either full table or from a partial last 3 days data based on a UI filter criteria.If filter was allowed, I would have created 2 different projection ,one with last 3 days data filter condition and then other with full data.
Use views for this purpose that are hitting the same projection but have their own predicates.
Related
I am recording the data for 3 counters and have the choice of using either of following schema:
Date|Sensor|Value
Date|Sensor1Value|Sensor2Value|Sensor3Value
When visualizing using either of the above schemas, x-axis will be the date. In case of 1st schema the sensor will be the legend and value will be the y-axis.
Whereas in case of the 2nd schema, each column will need to be added as y-axis, and there will be no legend.
What amongst the above 2 schemas are better suited for reporting (plotting graphs)?
The best answer will depend on 3 things:
the type of visualizations you're trying to build
which visualization(s) tool you're planning to use and
if you plan to add more sensor values in the future
Essentially, you're either going to pivot your data when storing it (second schema model with 1 column for each value) or you're going to store the data and rely on the visualization or your database query to perform the pivot logic.
In my experience in working with BI and analytics tools, it's almost always better to store data using the first Model (Date | Sensor | Value). This will provide the most flexibility when it comes to visualization tools and also if you need to add future sensor values, you won't need to modify your database table structure. If you need to convert your data into the second model, you can always build a View or temp table that uses a dynamic pivot query.
I’m relatively new to Tableau and have a question.
I want to create a heatmap show the location of two different groups of people. I’ve learned how to overlay maps using dual axis but the problem I keep running into is that each group requires different filters to aggregate the data the way I want.
Basically, I want to show:
Group1.id IF charge_id IS NOT NULL
And
Group2.id IF status = ‘ACTIVE’
Whenever I create a calculated field with one of the above calculated fields and place it in the filters box it automatically removes the other group from the map because the filters contradict one and other.
Help is much appreciated 😊
The filter shelf applies to the entire worksheet, so if you want to “filter” each field selectively, use an IF expression in a calculated field that evaluates to null when you don’t want that field in the view.
Give sample data if you want more detail
I am building a Custom SSIS data flow control which will provide three out put flow based on some rules validation. Please help me what exactly I need to implement in ProcessInput method to redirect data in these three output based on the some logic applied on the input
If I understand correctly, I think you want to route each 1 of the 3 outputs from the Custom Control component shown in your data flow, to various different destinations based on conditions. For that, you could use a CONDITIONAL SPLIT Component as shown below.
You can split the input into 2 or more row streams by giving the CONDITIONAL SPLIT various conditions that look at column values etc.
If my understanding is incorrect, then please update your question with more details on your situation.
I'am doing a GIS map, all is ready, but I still need rivers and lakes.
1. Where to find the list of all layers existing on OSM ?
2. how/where to download one layer for a given area ? (water, lakes / for a country)
OSM's primary data format has no equivalent of the GIS concept of "layers". Instead, everything is together, and "tags" are used to identify different features.
You can download country-by-country OSM downloads from Geofabrik.
Then you might consider:
Use osmosis to filter the XML data, eg filter to objects having tags water=*
Alternatively, take an OSM data dump and use osm2pgsql to convert the data into a postGIS database that I think involves layers.
I have a content type that stores two numerical values, effectively the minimum and maximum of a range.
I would like to configure the views module filter so that it will display nodes where the node range is contained within or overlaps a range specified in the view.
Views does not allow mixed OR and AND filters. You can configure an existing filter to show all nodes where N > 30 AND N < 50 (between, excluding, 30 and 50).
If you want more complex filters, e.g. filters that have business logic, or filters that create either/or conditions, you can define them yourself, trough hook_views. This is badly documented and requires a lot of googling and reading existing filter code.