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How big can a MySQL database get before performance starts to degrade
...data. The most important scalability factor is RAM. If the indexes of your tables fit into memory and your queries are highly optimized, you can serve a reasonable amount of requests with a average machine.
The number of records do matter, depending of how your tables look like. It's a difference ...
Combining “LIKE” and “IN” for SQL Server [duplicate]
...y, the IN statement creates a series of OR statements... so
SELECT * FROM table WHERE column IN (1, 2, 3)
Is effectively
SELECT * FROM table WHERE column = 1 OR column = 2 OR column = 3
And sadly, that is the route you'll have to take with your LIKE statements
SELECT * FROM table
WHERE column...
How to create a printable Twitter-Bootstrap page
...
Bootstrap 3.2 update: (current release)
Current stable Bootstrap version is 3.2.0.
With version 3.2 visible-print deprecated, so you should use like this:
Class Browser Print
-------------------------------------------------
.visible-print-block ...
Why is Dictionary preferred over Hashtable in C#?
In most programming languages, dictionaries are preferred over hashtables.
What are the reasons behind that?
19 Answers
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How to make an image center (vertically & horizontally) inside a bigger div [duplicate]
...
another way is to create a table with valign, of course. This would work regardless of you knowing the div's height or not.
<div>
<table width="100%" height="100%" align="center" valign="center">
<tr><td>
<img sr...
PostgreSQL: How to pass parameters from command line?
...'"
and then refer to the variables in sql as :v1, :v2 etc
select * from table_1 where id = :v1;
Please pay attention on how we pass string/date value using two quotes " '...' "
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SQLite: How do I save the result of a query as a CSV file?
...ex = False)
You can customize the query to only export part of the sqlite table to the CSV file.
You can also run a single command to export all sqlite tables to CSV files:
for table in c.execute("SELECT name FROM sqlite_master WHERE type='table';").fetchall():
t = table[0]
df = pd.read_sql...
SQL Query to concatenate column values from multiple rows in Oracle
...es of the ename column (concatenated with a comma) from the employee_names table in an xml element (with tag E)
extract the text of this
aggregate the xml (concatenate it)
call the resulting column "Result"
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Changing column names of a data frame
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Try setnames() in the data.table package. Use something like setnames(DT,"b","B") or setnames(DT,c("a","E"),c("A","F"))
– dwstu
Aug 11 '14 at 17:23
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Database Structure for Tree Data Structure
... Considering a structure as in number one topic (organizational structured table (not employee structured) with ParentId referenced in the same table), I need to set who is the boss of a certain area. I will assign all the employees of that specific area directly to it. Where would you put the boss ...