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How to print the contents of RDD?
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c.take(10)
and Spark newer version will show table nicely.
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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
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Another point is that if table1 .a contains NULL the EXISTS query will not return this row but the NOT IN query will if table2 is empty. NOT IN vs. NOT EXISTS Nullable Columns: SQL Server
– Martin Smith
Jun 19 '...
Search for all occurrences of a string in a mysql database [duplicate]
...how to locate all occurrences of a url in a database. I want to search all tables and all fields. But I have no idea where to start or if it's even possible.
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Difference between one-to-many and many-to-one relationship
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From this page about Database Terminology
Most relations between tables are one-to-many.
Example:
One area can be the habitat of many readers.
One reader can have many subscriptions.
One newspaper can have many subscriptions.
A Many to One relation is the same as o...
How to deal with SQL column names that look like SQL keywords?
...ause I didn't make it.
Am I allowed to do something like SELECT from FROM TableName or is there a special syntax to avoid the SQL Server being confused?
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Saving timestamp in mysql table using php
I have a field in a MySQL table which has a timestamp data type. I am saving data into that table. But when I pass the timestamp ( 1299762201428 ) to the record, it automatically saves the value 0000-00-00 00:00:00 into that table.
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Set NOW() as Default Value for datetime datatype?
I have two columns in table users namely registerDate and lastVisitDate which consist of datetime data type. I would like to do the following.
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Effect of NOLOCK hint in SELECT statements
...2) Yes, a select with NOLOCK will allow other queries against the effected table to complete faster than a normal select.
Why would this be?
NOLOCK typically (depending on your DB engine) means give me your data, and I don't care what state it is in, and don't bother holding it still while you re...
What are the differences between “=” and “
...expression). In fact, ?Syntax in R gives the following operator precedence table, from highest to lowest:
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‘-> ->>’ rightwards assignment
‘<- <<-’ assignment (right to left)
‘=’ assignment (right to left)
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But is this the on...
How to design a database for User Defined Fields?
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If performance is the primary concern, I would go with #6... a table per UDF (really, this is a variant of #2). This answer is specifically tailored to this situation and the description of the data distribution and access patterns described.
Pros:
Because you indicate that some UDFs
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