How to Troubleshoot Files That Take a Long Time to Open in Q

If a project takes a seemingly unreasonably long-time to open or compute it is likely that the cause of this is one or more of the following reasons:

The data files are saved on a network and the network is slow. You can remedy this by saving your file on your computer
The first table in the project is very slow to compute (see Tables Take a Long Time to Compute).
It is a large file, but it is not saved as an SPSS file. Q can load large SPSS files much faster than it can load other formats. If your data is large and it is in a different format then consider resaving it as an SPSS file (Tools | Save Data as SPSS File...).
It is a large uncompressed SPSS file (1 GB or more). These are very slow to load, and slow to save as QPacks for use in dashboards. You can import the data into Q, omitting all automatic import options, then resave it as a compressed SPSS file (Tools | Save Data as SPSS File...) and update your project with the compressed file. You should notice a dramatic reduction in the size of the data file.
It is a large file, is saved as an SPSS file, but is still slow. See How to Work with Large Data Files.
Omit old data (e.g. if you are only showing the last 12 months of data, then delete earlier data) from your source data file. See How to Delete Cases (Observations).
Omit unused variables, e.g. variables used in previous versions of your projet that you no longer need. See How to Delete Variables From a Project.

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