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Tag: indexing

Email address lookup in SQL Server

We have a large subscriber database and have a lookup based on email address of type nvarchar(100). It sometimes times out probably because of a large scan of it. I want to improve this, but weary of some of the options. Would an index on it be ok, I can handle the additional storage if needed, or a computed column

What could be the possible drawbacks of using force index clause in mysql query? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 1 year ago. Improve this question Sample Example – SELECT * FROM table_name FORCE INDEX (index_list) WHERE condition; Without using force index, mysql’s query optimiser decides

What is an on-disk structure?

An index is an on-disk structure. I couldn’t find anything understandable. For example, I found this Is it like a file system? Answer It just means that the index is physically stored on disk, as opposed to “only exists in-memory”. Your link is not related at all.

MySQL GROUP BY slows down query x1000 times

I’m struggling with setting up proper, effective index for my Django application which uses MySQL database. The problem is about article table which for now has a little more than 1 million rows and querying isn’t as fast as we want. Article table structure looks more or less like below: After many tries I came that below index gives best