Changes between Version 62 and Version 63 of DatabaseBasedAnalysis


Ignore:
Timestamp:
08/06/18 15:19:11 (6 years ago)
Author:
tbretz
Comment:

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  • DatabaseBasedAnalysis

    v62 v63  
    599599I have kept that here for convenience (and with the current server, it works, simply because the optimizer does not shuffle the columns.
    600600
    601 Now let's have a look at how the query should look correctly ('''Don't panic!'''):
     601Now let's have a look at how the query should look correctly (''' Don't panic! '''):
    602602
    603603{{{#!sql
     
    745745}}}
    746746
    747 Why is this so much faster? I guess it has two reasons:
     747Note that this is the result of the analysis of a dataset which, as a whole, is more than 100GB and even reduced to Crab after quality cuts still is of the order of GB! Why is this so much faster? I guess it has two reasons:
    748748
    7497491) Only variables which are really needed in the next step are kept (reduces memory consumption)
     
    752752Another example (apart from the obvious difficulty to read the query) is that it is very well structured. For each step it is very well defined what values
    753753are available from the previous step (the fields which are requested in each SELECT statement) and it is very well defined in which order the algorithm is executed.
     754
     755If somebody find a way to write that query in an easier readable way, I would be glad to know.