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Type:
Question
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Resolution: Done
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: JavaScript
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None
I want to replace the collection field based on a map table, like
| old_src | new_src |
|---|---|
| 1 | 448 |
| 5 | 449 |
| ... | ... |
So I write a very simple JavaScript.
db_name = 'mydb' collection_name = 'mycoll' src_map = [ [1,448], [5,449], [6,450], [8,451], [9,452], [10,453], [11,454], [12,455], [14,456], [15,457], [16,458], [17,459], [18,460], [20,461], [22,462], [23,463], [24,464], [25,465], [26,466], [27,467], [29,468] ] db = db.getSiblingDB(db_name) for (x in src_map) { old2new_map = src_map[x]; print("Changing src: " + String(old2new_map[0]) + " --> " + String(old2new_map[1]) + " ... "); db[collection_name].update({"src":old2new_map[0]},{$set:{"src":old2new_map[1]}},{multi:true}); print("Done.") }
I use update function within a for loop to do this. But it's so slow. This collection contains more than 1000000 objects, and each update will execute more than 10 mins(even if src field has a index).
How to optimize this script? Is there any way to update the whole may in a single function? Or use multi thread way to let the update function parallelly?