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Is the primary key automatically indexed in MySQL?
...are frequently used in where clauses, and in any kind of sorting, such as "order by".
You might be working on a more complex database, so it's good to remember a few simple rules.
Indexes slow down inserts and updates, so you want to use them carefully on columns that are FREQUENTLY updated.
Index...
What does “program to interfaces, not implementations” mean?
...wered Apr 23 '10 at 10:31
this. __curious_geekthis. __curious_geek
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Are static class instances unique to a request or a server in ASP.NET?
...ferent requests may or may not be handled by the same worker process.
In order to share data with a specific user and across requests, use HttpContext.Current.Session.
In order to share data within a specific request, use HttpContext.Current.Items.
In order to share data across the entire applicat...
psql - save results of command to a file
... (your query) to 'file path' csv header;
Example
\copy (select name,date_order from purchase_order) to '/home/ankit/Desktop/result.csv' cvs header;
Hope this help you.
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Converting a Java Keystore into PEM Format
...d certificates 139848775526048:error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt:evp_enc.c:539: 139848775526048:error:23077074:PKCS12 routines:PKCS12_pbe_crypt:pkcs12 cipherfinal error:p12_decr.c:104: 139848775526048:error:2306A075:PKCS12 routines:PKCS12_item_decrypt_d2i:pkcs1...
Create a tar.xz in one command
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Given the ordering is important with the dash, it's probably best to assume the ordering is always important, and put the f last, even without the dash.
– mwfearnley
Aug 24 '16 at 14:53
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Add a column to existing table and uniquely number them on MS SQL Server
...be of type IDENTITY (auto-increment), or you want to be specific about the order in which your rows are numbered, you can add a column of type INT NULL and then populate it like this. In my example, the new column is called MyNewColumn and the existing primary key column for the table is called MyP...
Why do you have to call .items() when iterating over a dictionary in Python?
...te over the same items. Implementation-wise they are different operations (__contains__ vs. __iter__). But that little inconsistency would be somewhat confusing and, well, inconsistent.
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What is the difference between dict.items() and dict.iteritems() in Python2?
...= dct.items() and then modify dct by adding/deleting keys or dct[k] = other_v, items will stay the same.
– djs
May 5 '12 at 3:07
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HashSet vs. List performance
... Even if you say your List<T> wouldn't have duplicates and iteration order doesn't matter making it comparable to a HashSet<T>, its still a poor choice to use List<T> because its relatively less fault tolerant.
That said, I will inspect some other aspects of performance,
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