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MongoDB - Update objects in a document's array (nested updating)
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For question #1, let's break it into two parts. First, increment any document that has "items.item_name" equal to "my_item_two". For this you'll have to use the positional "$" operator. Something like:
db.bar.update( {user_id : 123456...
How to shrink/purge ibdata1 file in MySQL
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That ibdata1 isn't shrinking is a particularly annoying feature of MySQL. The ibdata1 file can't actually be shrunk unless you delete all databases, remove the files and reload a dump.
But you can configure MySQL so that each table, in...
Why use symbols as hash keys in Ruby?
...hed keys" against each other.
Long answer:
https://web.archive.org/web/20180709094450/http://www.reactive.io/tips/2009/01/11/the-difference-between-ruby-symbols-and-strings
http://www.randomhacks.net.s3-website-us-east-1.amazonaws.com/2007/01/20/13-ways-of-looking-at-a-ruby-symbol/
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How do I find a specific table in my EDMX model quickly?
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179
Click in an open area of the designer:
Go to the Properties tab:
In the dropdown box at...
How to name variables on the fly?
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118
Use assign:
assign(paste("orca", i, sep = ""), list_name[[i]])
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What is the difference between .text, .value, and .value2?
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241
.Text gives you a string representing what is displayed on the screen for the cell. Using .Text ...
ElasticSearch: Unassigned Shards, how to fix?
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118
By default, Elasticsearch will re-assign shards to nodes dynamically. However, if you've disab...
How do you truncate all tables in a database using TSQL?
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17 Answers
17
Active
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How does the HyperLogLog algorithm work?
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156
The main trick behind this algorithm is that if you, observing a stream of random integers, se...
Convert UNIX epoch to Date object
...as integers representing the number of seconds since the UNIX epoch (e.g. 1352068320 ), but Date objects seem more appropriate for plotting. How can I do the conversion?
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