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Is there any performance gain using a CTE over a derived table?
Started by D Scott on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
The server was fairly well loaded, the variation in times on runs was pretty significant, and I can't believe the execution plan was that different, but it still seemed ... .
I've used CTEs a lot and it does actually appear to run faster in some scenarios .
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I am running this query on mysql
SELECT ID FROM (SELECT ID, msisdn FROM (SELECT * FROM TT2));
and it is giving this error:
Every derived table must have its own alias.
what is wrong ?
Started by silverkid on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
I used the ....
As myalias) as anotheralias;
But why would you write this query in the first place?
Every derived table a table alias for every subquery/inline view:
SELECT y.ID FROM (SELECT x.ID, x.msisdn FROM (SELECT outwards.
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I have a derived table. Its based on one underlying physical database tables. The SQL transforms columns into rows. Anyway, there were some more columns added to the physical table so i adjusted the SQL to reflect these changes.
Here's the key. "Somehow...
Started by twebber on
, 12 posts
by 4 people.
Answer Snippets (Read the full thread at forumtopics):
Try naming....
I guess this is the better option.
I will have to delete my old defunct derived table first.
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Hello,
I have a class that derives from ActiveRecord::Base. This class has a subclass that is differentiated in the database by a type id column. How do I make sure that all the inherited active record functions in the derived classes append the type_...
Started by Mattew on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
That's why what Radar said about your column being.
Are doing is called Single Table Inheritance (STI).
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Let's say I need to query the associates of a corporation. I have a table, "transactions", which contains data on every transaction made.
CREATE TABLE `transactions` ( `transactionID` int(11) unsigned NOT NULL, `orderID` int(11) unsigned NOT NULL, `customerID...
Started by FRKT on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
At some point in there, as your query joins the transaction table to the transaction table.
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Sometimes we can write a query with both derived table and temporary table. my question is that which one is better? why?
Started by masoud ramezani on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Derived....
Derived table is better as temporary tables become more complex when its is used more and more
A derived table is the result of using another SELECT statement in the FROM clause of a SELECT statement.
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I have an abstract base class for audit properties. For brevity say it has one property
Public MustInherit Class AbstractAuditableEntity ... Public Property CreatedTime() As DateTimeOffset ... End Class
And then my auditable domain objects inherit from...
Started by cpedros on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
It works great if you database table map more or less 1:1 to your domain.
Of the limitations of Linq-to-SQL.
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I'm not sure of the terminology here, so let me give an example. I have this query:
SELECT * FROM Events Id Name StartPeriodId EndPeriodId 1 MyEvent 34 32
In here, the PeriodIds specify how long the event lasts for, think of it as weeks of the year specified...
Started by colinramsay on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Using these two date it joins with the periods table on values inside.
Specified on the event.
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UPDATE: I found a solution. See my Answer below.
My Question How can I optimize this query to minimize my downtime? I need to update over 50 schemas with the number of tickets ranging from 100,000 to 2 million. Is it advisable to attempt to set all fields...
Started by hobodave on
, 7 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
This derived behemoth would be up to a 2, then filtering out what....
I was taking my well-indexed it attempts to join the shifts and shift_positions table.
Because of the huge derived table, and the subsequent JOINs onto this.
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What's the difference between a derived object and a base object in c++,
especially, when there is a virtual function in the class.
Does the derived object maintain additional tables to hold the pointers
to functions?
Started by MainID on
, 12 posts
by 12 people.
Answer Snippets (Read the full thread at stackoverflow):
derived - is the object the....
The respective objects' representation in memory?
Both the base class and the derived class will have a tableDerived is Base, but Base is not a Derived
base- is the object you are deriving from.
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