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Immutable vs Mutable types
I'm confused on what an immutable type is. I know the float object is considered to be immutable, with this type of example from my book:
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How important is the order of columns in indexes?
I've heard that you should put columns that will be the most selective at the beginning of the index declaration. Example:
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What is the difference between precision and scale?
What is the difference between precision and scale in Oracle? In tutorials they usually leave scale empty and set precision to 6 when creating a primary key.
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How to HTML encode/escape a string? Is there a built-in?
...cape the chars ' < ' and ' & ' as HTML entities. The less fuss the better.
8 Answers
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Passing multiple error classes to ruby's rescue clause in a DRY fashion
I have some code that needs to rescue multiple types of exceptions in ruby:
3 Answers
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Why do you need to invoke an anonymous function on the same line?
I was reading some posts about closures and saw this everywhere, but there is no clear explanation how it works - everytime I was just told to use it...:
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Calculate a Running Total in SQL Server
Imagine the following table (called TestTable ):
15 Answers
15
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Can Powershell Run Commands in Parallel?
I have a powershell script to do some batch processing on a bunch of images and I'd like to do some parallel processing. Powershell seems to have some background processing options such as start-job, wait-job, etc, but the only good resource I found for doing parallel work was writing the text of a...
Detect URLs in text with JavaScript
... a valid URL. There
are some punctuation rules for
splitting it up. Absent any
punctuation, you still have a valid
URL.
Check the RFC carefully and see if you
can construct an "invalid" URL. The
rules are very flexible.
For example ::::: is a valid URL.
The path is ":::...
PostgreSQL Crosstab Query
Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
6 Answers
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