Optimize SELECT DISTINCT (with existing index) to avoid sequential scan
123691
Postgres is performing sequential scan instead of index scan
12037
Remove duplicate values from query result
32521
MySQL COUNT DISTINCT
99373
SQL server select distinct rows using most recent value only
100486
How to select unique records by SQL
139728
Query speed based on order of columns
65505
Any way to do DISTINCT ON?
93921
Select groups based on number of unique / distinct values
32341
MySQL pagination without double-querying?
16198
LINQ's Distinct() on a particular property
19227
When is a full table scan better than index scan?
8316
Do frequent DML operations on a table with indexes and huge data affect SELECT query performance?
86649
What's the most efficient way to select the last n rows in a table without changing the table's structure?
25114
MYSQL sum() for distinct rows
55676
SQL distinct for 2 fields in a database
5073
How can I force MySQL to IGNORE ALL indexes?
46
Oracle: function based index selective uniqueness