What is SQL logical reads?
A logical read occurs every time the Database Engine requests a page from the buffer cache. If the page is not currently in the buffer cache, a physical read first copies the page from disk into the cache. So, a logical read is when the query engine needs to read data.
What is query store in SQL?
The SQL Server Query Store feature provides you with insight on query plan choice and performance. It separates data by time windows so you can see database usage patterns and understand when query plan changes happened on the server. You can configure query store using the ALTER DATABASE SET option.
Where can I find logical reads in SQL Server?
Below are the ways to check logical Reads:
- set statistics io on.
- sys.dm_exec_query_Stats. by executing the below statement we can find detailed info about reads/writes. select * from sys.dm_exec_query_Stats.
- SQL Profiler: by executing the sql profiler on that database we can find out logical reads..
How to find the top CPU consuming queries in query store?
Find the queries with a high number of physical reads in Query Store. If they match the queries with high IO waits, consider introducing an index on the underlying entity, in order to do seeks instead of scans, and thus minimize the IO overhead of the queries. Find the top CPU consuming queries in Query Store.
Which is the most important setting in query store?
This is the most important setting that directly affects the operation mode of Query Store. While Query Store collects queries, execution plans, and statistics, its size in the database grows until this limit is reached.
How does the SQL Server query store work?
The data is sorted by average CPU time, putting the greatest CPU consumers on the top of the list. Additional useful filters are provided, but commented out, for sorting on duration, execution count, logical reads, and average row count. This query will return multiple rows if multiple execution plans exist.
What’s the bad thing about logical reads in SQL?
What’s bad is an inordinate number of logical reads. If you’re returning 3 rows of data, but the query engine had to scan 200 million rows of the table to do it, that’s going to be very slow and you can probably improve that by rewriting the query or adding an index. I would start by looking at how complex the queries in your stored procedure are.