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2
votes
0answers
15 views

How does the use of derived tables speed up sorting?

In the article 45 Ways To Speed Up Firebird Database, it states that Use derived tables to optimize SELECT with ORDER BY/GROUP BY Another way to optimize SQL query with sorting is to ...
1
vote
0answers
54 views

Get unique rows based on max of a column in mysql

I came across many solutions like the one in this question. However, they all are restricted to data from one table. I'm very very new to SQL. I'd like to get the same results as in the linked ...
0
votes
2answers
116 views

How are derived table implemented in MySQL

When MySQL makes a derived table as a result of SELECT (SELECT ...) etc or SELECT * FROM a JOIN (SELECT * from B) etc or SELECT * FROM (SELECT ...) Are these derived temporary tables created in-...
5
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2answers
10k views

Are there advantages to using temporary tables over derived tables in SQL Server?

I read the derived tables have better performance than temporary tables, but anyway many SQL Server developers prefer the second ones. Why? I must do queries with large data (millions records) and I ...