I'm trying to add a new column to my SSAS cube. The column is a date field, and links to my DimDate table (a Date dimension). This date represents the project completion date.
However.... not all of the projects have a project completion date due to old projects not ever being assigned this value. And this is expected. We don't want to put bogus dates into the field just to get SSAS to work.
When processing the cube, it crashes with:
Errors in the OLAP storage engine: The attribute key cannot be found when
processing: Table: 'dbo_FactMyTable', Column: 'MyDate_id', Value: '0'.
The attribute is 'Date Id'.
I can't disable "missing values" for the entire project because in most cases, this really is an error. How can I disable missing values for this dimension?
Or is there a better way to handle missing dates/values like this?
Small correction - based on your question, you need to change Processing error handling for special Measure Group, not Dimension. You can do it for all dimensions linked to some measure group, but not to specific dimension.
You can process individual measure group with _Table: 'dbo_FactMyTable'_ first with necessary missing value settings, and then - process rest of your cube with default settings.
Main problem here - how to process rest of the cube. You might have sophisticated system which creates processing XMLA scripts dynamically based on data update knowledge (I do it with SSIS); in this case you would not ask this question. Suppose your environment is simpler - you update cube and would like to process it as a whole completely. In such scenario I would sudgest the following workflow:
Process Default all Dimensions (will do initial processing or in structure changes)
Process Update all Dimensions
Process Cube with Unprocess - invalidating it
Process your special measure group
Process Cube with Process Default
This will first update Dimensions, then - clear processing status flag from all measure groups in the Cube. After that you process your measure group with special flags; this set processing status for this MG. And then during Process Default on Cube - only unprocessed MGs will be covered, which excludes your special MG from processing scope.
The answer is a bit complicated, but this article did a great job of explaining it, including screen shots for the SSAS-challenged like me.
http://msbusinessintelligence.blogspot.com/2015/06/handling-null-dates-in-sql-server.html?m=1
Related
I a new to this site and to SSAS in general. I am currently doing some "on the job training" trying to put together an SSAS cube and I am experiencing some problems.
When I try to process the Cube it fails. This happens due to the fact that the Fact table used for the cube contains some 13 rows that have dates that are outside of the range of the Date dimension that I am using.
I am not sure what I should do to get around/fix this.
Exclude the rows?
Change the dimension?
I have tried to find an answer to this on my own, but it seems that my phrasing of the issue/problem has so far stopped me from finding relevant information.
Any advice or ideas would be greatly appreciated!
/Chriss
I am new to Qlikview and after several failed attempts I have to ask for some guidance regarding charts in Qlikview. I want to create Line chart which will have:
One dimension – time period of one month broke down by days in it
One expression – Number of created tasks per day
Second expression – Number of closed tasks per day
Third expression – Number of open tasks per day
This is very basic example and I couldn’t find solution for this, and to be honest I think I don’t understand how I should setup my time period dimension and expression. Each time when I try to introduce more then one expression things go south. Maybe its because I have multiple dates or my dimension is wrong.
Here is my simple data:
http://pastebin.com/Lv0CFQPm
I have been reading about helper tables like Master Callendar or “Date Island” but I couldn’t grasp it. I have tried to follow guide from here: https://community.qlik.com/docs/DOC-8642 but that only worked for one date (for me at least).
How should I setup dimension and expression on my chart, so I can count the ID field if Created Date matches one from dimension and Status is appropriate?
I have personal edition so I am unable to open qwv files from other authors.
Thank you in advance, kind regards!
My solution to this would be to change from a single line per Call with associated dates to a concatenated list of Call Events with a single date each. i.e. each Call will have a creation event and a resolution event. This is how I achieve that. (I turned your data into a spreadsheet but the concept is the same for any data source.)
Calls:
LOAD Type,
Id,
Priority,
'New' as Status,
date(floor(Created)) as [Date],
time(Created) as [Time]
FROM
[Calls.xlsx]
(ooxml, embedded labels, table is Sheet1) where Created>0;
LOAD Type,
Id,
Priority,
Status,
date(floor(Resolved)) as [Date],
time(Resolved) as [Time]
FROM
[Calls.xlsx]
(ooxml, embedded labels, table is Sheet1) where Resolved>0;
Key concepts here are allowing QlikView's auto-conatenate to do it's job by making the field-names of both load statements exactly the same, including capitalisation. The second is splitting the timestamp into a Date and a time. This allows you to have a dimension of Date only and group the events for the day. (In big data sets the resource saving is also significant.) The third is creating the dummy 'New' status for each event on the day of it's creation date.
With just this data and these expressions
Created = count(if(Status='New',Id))
Resolved = count(if(Status='Resolved',Id))
and then
Created-Resolved
all with full accumulation ticked for Open (to give you a running total rather than a daily total which might go negative and look odd) you could draw this graph.
For extra completeness you could add this to the code section to fill up your dates and create the Master Calendar you spoke of. There are many other ways of achieving this
MINMAX:
load floor(num(min([Date]))) as MINTRANS,
floor(num(max([Date]))) as MAXTRANS
Resident Calls;
let zDateMin=FieldValue('MINTRANS',1);
let zDateMax=FieldValue('MAXTRANS',1);
//complete calendar
Dates:
LOAD
Date($(zDateMin) + IterNo() - 1, '$(DateFormat)') as [Date]
AUTOGENERATE 1
WHILE $(zDateMin)+IterNo()-1<= $(zDateMax);
Then you could draw this chart. Don't forget to turn Suppress Zero Values on the Presentation tab off.
But my suggestion would be to use a combo rather than line chart so that the calls per day are shown as discrete buckets (Bars) but the running total of Open calls is a line
I have a .RDL report which I designed in BIDS and have deployed to my report server. The report asks for three parameters before viewing report: Year, Month and Customer ID. The report works great and does exactly what it is supposed to.
While I used to run each report individually because there were 2-3 customers, now there are 30+ customers who receive the report, so I wanted to switch to a more automated fulfillment method to get the reports generated. After doing some research it appears that a using Report Manager to create a "Data Driven Subscription" (DDS) using the "Windows File Share" option gives me the capabilities I need.
As part of creating the DDS, I created a table called [Subscription] which is a table containing one row for each customer receiving the report and has the following columns:
Year
Month
CustomerID
FileName
FileLocation
Overwrite
Format
...so through using the DDS Wizard in Report Manager, I was able to successfully set up a Data Driven Subscription (which is linked to various columns in the [Subscription] table) which creates a new report for each customer in the [Subscription] table, saves [and overwrites, if necessary] it in a location of my choosing as a PDF (specified in [Subscription].[FileLocation], or the FileLocation column of my table for each row), and runs every minute (I plan on changing frequency to once a week, eventually).
This works flawlessly, giving me a new set of 30 reports in the directory of my choosing, with each report having a name I assigned in the FileName column of my table. Exactly what I was looking for.
HERE'S THE PROBLEM: When I update the FileLocation or FileName (or anything, really) in the [Subscription] table - it doesn't pick up the changes right away. Sometimes it doesn't even pick it up at all (for example I updated the [ReportName] column for one customer from Report_711622 to SpecialReport_711622, so that the output file for that customer should be named SpecialReport_711622 while all of the other reports should be called Report_XXXXX [no Special prefix]. But the file name of report for Customer 711622 remains the same!
It's almost like the job only see's what it needs to do once a day, and then does not go back and reference the [Subscription] table until I leave for the night, then when I come back in the morning it picks up the change.
Since I am about to scale this process out to a large customer-base using a different report, I need to be able to make edits to the [Subscription] table and have them get picked up by the Data Driven Subscription immediately (and if not immediately, at least a fixed interval of time that I can adjust, so that I can know 100% when the change will get picked up).
Does anyone know what's causing my lag? How do I change it so that updates to the Subscription table get picked up regularly? I'm also having issues with creating new DDS on other reports (following the exact process outlined above) - I've created the subscriptions, for every minute, and it says they are running and the number of outputs match the number of customers with 0 errors, but there are no files in the drive I specified (or anywhere else I've looked, for that matter).
Any help would be greatly appreciated!
I think the answer lies in the mechanism SSRS uses. There are a few places "lag" can occur.
The subscription is in fact an SQL Agent job which creates a record in the Event table. This table is a queue that SSRS checks to do scheduled tasks.
There is a small amount of time between the moment the subscription creates the Event record and the moment SQL reads it and starts creating the dataset for your DDS. The creation of the DDS dataset takes some time, too. In this time, the subscription will be in the Pending state. If you change anything in the data during this time, The subscription will still use the old data as report parameters. So obviously you will not notice your change until the next scheduled run.
Which brings me to the following: if a subscription is still being run and the next schedule kicks in (chances are, because yours runs every minute), the engine will not execute it, but wait for the next subscription schedule, and so on. So that's another possibility of lag - and cause of missing reports for a certain schedule minute. The subscription processes reports sequentially, one row from your DDS recordset at a time. Again, this takes some time. You can also see that in the subscription window when it says: # of # processed.
I suggest you look at the Event table in the database ReportServer during an execution. Also the ExecutionHistory views (there are 3) may be interesting. A scheduled run shows up as a RequestType = 1 and generates one record for each report. You can see the exact timing and parameters of each report that is run in the subscription. You may be able to extract the data you need to resolve your other issues.
EDIT: Here is a more elaborate guide to DDS data and events
http://blogs.msdn.com/b/deanka/archive/2009/01/13/diagnosing-and-troubleshooting-subscriptions.aspx
http://blogs.msdn.com/b/deanka/archive/2010/02/16/troubleshooting-subscriptions-part-ii-using-the-report-services-trace-log-file.aspx
Could this "Double-Hop" problem be the source of my issues? I'm so stuck on this one!
The Double-Hop Problem - MSDN Knowledgecast
Is there a way to access system tables in a SSAS cube calcuation?
For example the following query can be executed on a SSAS cube to return a last processed date:
SELECT LAST_DATA_UPDATE FROM $System.MDSCHEMA_CUBES WHERE CUBE_NAME = 'Cube'
How would one access this information in a calculation?
Background: We were using ASSP before (a third party sproc) to get the last cube processed date. Recently, this sproc threw an exception on one of our cubes and caused SSAS to go down. Using the above line of MDX did not have this behavior. I would rather not have our cube depend on third party code so I am looking for a way to access LAST_DATA_UPDATE in a calc for a specific cube name.
I usually include a detached Dimension in my cubes e.g. ".Cube Information" which includes attributes like this. Other useful attributes could expose the currency of the data e.g. when did the last underlying ETL process complete, or the release/build of your cube.
I feed this "Cube Information" dimension from a SQL view which returns a single row with whatever data is needed - you could use your SELECT statement. It also needs to return a Key column with a fixed value e.g. 1.
By "detached" I mean the "Cube Information" dimension has no entries in the Cube Dimension Relationship tab.
In the cube Calculation script, I assign the DEFAULT_MEMBER property for that dimension to the fixed Key value from the SSAS view.
Any client tool can then access those Dimension attributes.
I need to scheduled events, tasks, appointments, etc. in my DB. Some of them will be one time appointments, and some will be reoccurring "To-Dos" which must be checked off. After looking a google's calendar layout and others, plus doing a lot of reading here is what I have so far.
Calendar table (Could be called schedule table I guess): Basic_Event Title, start/end, reoccurs info.
Calendar occurrence table: ties to schedule table, occurrence specific text, next occurrence date / time????
Looked here at how SQL Server does its jobs: http://technet.microsoft.com/en-us/library/ms178644.aspx
but this is slightly different.
Why two tables: I need to track status of each instance of the reoccurring task. Otherwise this would be much simpler...
so... on to the questions:
1) Does this seem like the proper way to go about it? Is there a better way to handle the multiple occurrence issue?
2) How often / how should I trigger creation of the occurrences? I really don't want to create a bunch of occurrences... BUT... What if the user wants to view next year's calendar...
Makes sense to have your schedule definition for a task in one table and then a separate table to record each instance of that separately - that's the approach I've taken in the past.
And with regards to creating the occurrences, there's probably no need to create them all up front. Especially when you consider tasks that repeat indefinitely! Again, the approach I've used in the past is to only create the next occurrence. When that instance is actioned, the next instance is then calculated and created.
This leaves the issue of viewing future occurrences. For this, you can start of with the initial/next scheduled occurrence and just calculate the future occurrences on-the-fly at display time.
While this isn't an exact answer to your question I've solved this problem before in SQL Server (though database here is irrelevant) by modeling a solution based on Unix's cron.
Instead of string parsing we used integer columns in a table to store the various time units.
We had events which could be scheduled; they could either point to a one-time schedule table that represented a distinct point in time (a date/time) or to the recurring schedule table which is modelled after cron.
Additionally remember to model your solution correctly. An event has a duration but the duration is unrelated to the schedule (but an event's duration may impact the schedule by causing conflicts). Do not try to model duration as part of your schedule.
In the past when we've done this, we had 2 tables:
1) Schedules -> Includes recurrence information
2) Exceptions -> Edit/changes to specific instances
Using SQL, it's possible to get the list of "Schedules" that have at least one instance in a given date range. Then you can expand in the GUI where each instance lies.