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How is a CRC32 checksum calculated?
...for computing a CRC: an algebraic approach, a bit-oriented approach, and a table-driven approach. In Reversing CRC - Theory and Practice*, each of these three algorithms/approaches is explained in theory accompanied in the APPENDIX by an implementation for the CRC32 in the C programming language.
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Is a Python dictionary an example of a hash table?
...looking up "values" of any type. Is this implemented internally as a hash table? If not, what is it?
4 Answers
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Does Foreign Key improve query performance?
Suppose I have 2 tables, Products and ProductCategories. Both tables have relationship on CategoryId. And this is the query.
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How to add JTable in JPanel with null layout?
I want to add JTable into JPanel whose layout is null . JPanel contains other components. I have to add JTable at proper position.
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Best database field type for a URL
I need to store a url in a MySQL table. What's the best practice for defining a field that will hold a URL with an undetermined length?
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Does a foreign key automatically create an index?
I've been told that if I foreign key two tables, that SQL Server will create something akin to an index in the child table. I have a hard time believing this to be true, but can't find much out there related specifically to this.
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Laravel Eloquent Sum of relation's column
... is no price column. It looks like eloquent is not looking at that Product table at all....
– theAdmiral
Feb 10 '14 at 15:22
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PHP function to make slug (URL string)
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sanitize is a strange, forgettable function name to generate a slug.
– rybo111
Jul 3 '15 at 13:52
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SQL server query to get the list of columns in a table along with Data types, NOT NULL, and PRIMARY
... to write a query on SQL server to get the list of columns in a particular table, its associated data types (with length) and if they are not null. And I have managed to do this much.
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select * vs select column
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It always pulls a tuple (except in cases where the table has been vertically segmented - broken up into columns pieces), so, to answer the question you asked, it doesn't matter from a performance perspective. However, for many other reasons, (below) you should always select ...