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Can I use distinct with GROUP BY?
Well, GROUP BY and DISTINCT have their own use. GROUP BY cannot replace DISTINCT in some situations and DISTINCT cannot take place of GROUP BY. It is as per your choice and situation how you are optimizing both of them and choosing where to use GROUP BY and DISTINCT.
What is the difference between GROUP BY and distinct?
Distinct is used to find unique/distinct records where as a group by is used to group a selected set of rows into summary rows by one or more columns or an expression. Group By operator is meant for aggregating/grouping rows where as distinct is just used to get distinct values.
How to speed up a SELECT DISTINCT query?
A lot will depend on the details of the query and the tables involved– your saying you “know the problem is with the DISTINCT” really limits the scope of available answers. Oftentimes, you can make such queries run faster by working around the distinct by using a group by instead:
How to SELECT DISTINCT values without using distinct keyword?
Distinct Values – Learn how to select distinct values in a table with and Without using SQL DISTINCT keyword with example queries. Below is the DUP_VALUES_TBL Table creation and data insertion queries. Set operators like Union, Minus, Intersect Performs sorting operation by default in ascending order.
How to select distinct from multiple table in SQL?
select distinct (col1, col2) from table Multi select in general can be executed safely as follows: select distinct * from (select col1, col2 from table) as x As this can work on most of the DBMS and this is expected to be faster than group by solution as you are avoiding the grouping functionality.
How many rows does a distinct query need?
The table in question has 2.5 million rows of data. The DISTINCT is needed for purposes not listed here (because I don’t want back a modified query, but rather just general information about making distinct queries run faster at the DBMS level, if possible).