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What's the (hidden) cost of Scala's lazy val?

...n suffer thread safety problem as mentioned in double check locking http://www.javaworld.com/javaworld/jw-05-2001/jw-0525-double.html?page=1 share | improve this answer | fo...
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What are the differences between vector and list data types in R?

... This and similar introductory questions are answered in http://www.burns-stat.com/pages/Tutor/hints_R_begin.html It is meant to be a gentle introduction that gets you up and running with R as quickly as possible. To some extent it succeeds. --- Edit: -- An attempt to explain further...
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ElasticSearch - Return Unique Values

...t body = { "size": 0, // Returning only aggregation results: https://www.elastic.co/guide/en/elasticsearch/reference/current/returning-only-agg-results.html "aggs" : { "langs": { "composite" : { "size": ITEMS_PER_PAGE, "sources" : [ ...
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Asynctask vs Thread in android

... there are lot of good resources over internet which may help you: http://www.vogella.com/articles/AndroidBackgroundProcessing/article.html share | improve this answer | fol...
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How many socket connections can a web server handle?

...0 Here is an up to date comparison of the fastest HTTP libraries - https://www.techempower.com/benchmarks/#section=data-r16&hw=ph&test=plaintext Test date: 2018-06-06 Hardware used: Dell R440 Xeon Gold + 10 GbE The leader has ~7M plaintext reponses per second (responses not connections) The...
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How can I clear the SQL Server query cache?

... Here is some good explaination. check out it. http://www.mssqltips.com/tip.asp?tip=1360 CHECKPOINT; GO DBCC DROPCLEANBUFFERS; GO From the linked article: If all of the performance testing is conducted in SQL Server the best approach may be to issue a CHECKPOINT and th...
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Embed SVG in SVG?

...height="100%" viewBox="-100 -100 200 200" version="1.1" xmlns="http://www.w3.org/2000/svg"> <circle cx="-50" cy="-50" r="30" style="fill:red" /> <image x="10" y="20" width="80" height="80" href="recursion.svg" /> </svg> ...
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nginx missing sites-available directory

...tep 3). Be sure to give it the right permissions/ownership. Likely root or www-data. Move or copy your separate config files (just like you have in /etc/nginx/sites-available) into the directory conf.d. Reload or restart nginx. Eat an ice cream cone. Any .conf files that you put into the conf.d d...
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Golang production web application configuration

...ess logs (and therefore leveraging system log rotation) Rewrites (naked to www, http:// to https://, etc.) nginx makes this very easy, and although you can serve directly from Go thanks to net/http, there's a lot of "re-inventing the wheel" and stuff like global HTTP headers involves some boilerpl...
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Using OpenSSL what does “unable to write 'random state'” mean?

... Yes, if you run from php web server, the user is www-data, and you should add "export" before every openssl: shell_exec('export RANDFILE=".rnd";openssl ecparam -genkey -name secp256k1')) – diyism Jun 21 '13 at 9:04 ...