psayre23
/ gist:c30a821239f4818b0709
Last active
March 9, 2026 09:44
Runtime Complexity of Java Collections
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| Below are the Big O performance of common functions of different Java Collections. | |
| List | Add | Remove | Get | Contains | Next | Data Structure | |
| ---------------------|------|--------|------|----------|------|--------------- | |
| ArrayList | O(1) | O(n) | O(1) | O(n) | O(1) | Array | |
| LinkedList | O(1) | O(1) | O(n) | O(n) | O(1) | Linked List | |
| CopyOnWriteArrayList | O(n) | O(n) | O(1) | O(n) | O(1) | Array |
terryjray
/ gist:3296171
Created
August 8, 2012 15:55
Enabling hstore for new postgresql 9.1 and rails 3 install on ubuntu 12.04
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| RAILS_ENV=production rake db:setup | |
| # produces the error below.....hmmm.....it's a no-worky | |
| psql:/yourprojectpath/yourproject/db/structure.sql:29: ERROR: could not open extension control file "/usr/share/postgresql/9.1/extension/hstore.control": No such file or directory | |
| # hstore postgresql extension needs to be installed, so.... | |
| sudo apt-get install postgresql-contrib | |
| # now your extension should be available to enable so log in with psql | |
| psql -d yourproject_production -U yourdbuser -W |