When you’re running a query, one of the things you should consider is that you might forget a filter and get way too much data from the database.
Secondly, that query might run for multiple hours and you don’t have multiple hours because you want to get to the part where you layout the report before running the query and returning all the data.
Here’s a few things you can do :
1) Create the query, save the query but don’t run it yet.
In the query panel, instead of blindly hitting Run, Hit Save and Close. This will save the query, but you won’t get data. Next, you can start modifying the layout of the report (use View>Structure) and when you’re ready, refresh the report to get your data (e.g. before leaving the office)
2) Limit the amount of data that can be returned by the query
If you don’t know in advance, how much data you’re going to get, maybe it’s a good idea, at first run, to limit the returned data to the first 10 or 100 lines, in stead of getting the lot. Especially, if you’re in doubt which kind of data will be returned by each of the fields.
When you click the options button, you get to choose how many lines you would like to get from the database:
this will of course return ‘Partial results’.
There you go folks – for the sake of prudence, don’t get all your data at once.