Comments on: Copying Amazon SimpleDB Domains http://avdi.org/devblog/2009/10/28/copying-amazon-simpledb-domains/ "...the three great virtues of a programmer: laziness, impatience, and hubris." -- Larry Wall Wed, 03 Mar 2010 21:56:22 -0800 http://wordpress.org/?v=2.8.5 hourly 1 By: avdi http://avdi.org/devblog/2009/10/28/copying-amazon-simpledb-domains/comment-page-1/#comment-783 avdi Mon, 30 Nov 2009 19:06:48 +0000 http://avdi.org/devblog/?p=285#comment-783 You're quite right, in some more recent scripts I've taken the next token into account. You're quite right, in some more recent scripts I've taken the next token into account.

]]> By: Stephen http://avdi.org/devblog/2009/10/28/copying-amazon-simpledb-domains/comment-page-1/#comment-782 Stephen Mon, 30 Nov 2009 17:08:38 +0000 http://avdi.org/devblog/?p=285#comment-782 Cool! The calculation of the count on line 13 isn't 100% correct though, as it won't work right on very large domains. This is because 'select count(*)' operations will return before they are complete if the operation is going to take longer than 5 seconds. I find this usually happens when the domain has >75k items.<br><br>Perhaps there's a more elegant way to solve this, but in my code, I do as follows to calculate the count of a domain:<br><br>next_token = nil<br>count = 0<br>begin <br> response = sdb.select("select count(*) from `#{domain_name}`", next_token)<br> count += response[:items][0]['Domain']['Count'][0].to_i<br> next_token = response[:next_token]<br>end while next_token Cool! The calculation of the count on line 13 isn't 100% correct though, as it won't work right on very large domains. This is because 'select count(*)' operations will return before they are complete if the operation is going to take longer than 5 seconds. I find this usually happens when the domain has >75k items.

Perhaps there's a more elegant way to solve this, but in my code, I do as follows to calculate the count of a domain:

next_token = nil
count = 0
begin
response = sdb.select(”select count(*) from `#{domain_name}`”, next_token)
count += response[:items]0['Domain']['Count']0.to_i
next_token = response[:next_token]
end while next_token

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