Changes between Version 62 and Version 63 of DatabaseBasedAnalysis
- Timestamp:
- 08/06/18 15:19:11 (6 years ago)
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DatabaseBasedAnalysis
v62 v63 599 599 I have kept that here for convenience (and with the current server, it works, simply because the optimizer does not shuffle the columns. 600 600 601 Now let's have a look at how the query should look correctly (''' Don't panic!'''):601 Now let's have a look at how the query should look correctly (''' Don't panic! '''): 602 602 603 603 {{{#!sql … … 745 745 }}} 746 746 747 Why is this so much faster? I guess it has two reasons:747 Note 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: 748 748 749 749 1) Only variables which are really needed in the next step are kept (reduces memory consumption) … … 752 752 Another 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 753 753 are 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. 754 755 If somebody find a way to write that query in an easier readable way, I would be glad to know.