Slow MySQL query with multiple sub-queries in where clause...

MySQL(5.7.26) query optimization, why select * is much faster that select id in my leading wildcard ...

Performance issues with recursive SQL Server stored procedure for hierarchical data...

Why removal of column from index improved performance?...

Slow query performance due to partitions...

Using discontinuous indices for pyomo optimization...

Table with 50 million data and adding index takes too much time...

Speed up query looking for gaps in time series in Mariadb...

plan_handle is always different for each query in SQL Server Cache...

Does "limit 1" increase performance for unique-value column queries...

trying to speed up a query - index isn't being used?...

How can I make sorting by a column in a joined table faster?...

How can I optimize this query to get faster result?...

Sargability of RIGHT/LEFT in SQL...

How can I join 2 tables together if columns I join on are of different data type?...

In MySQL, is a leftmost prefix of a composite index just as performant as an non-composite index?...

Slow postgresql query with distinct on subquery...

Why is the index not used in the query execution plan?...

optimize a SQL query flow...

MySQL optimize a SQL for a table without indexes...

optimizing a query that is always scan full table...

Optimize PostgreSQL query to insert users into the database...

Extremely slow distinct query on indexed column...

Optimize MariaDB simple query and what in fact cost is in explain json format statement...

How to index a mongo complex query...

Is there a way to write joining where clauses without AND operator?...

Enhance ordering on 280M rows of a column...

Oracle VERY slow when trying to create a table or a materialized view from 2 existing views...

Why is one of two nearly identical MySQL views so slow?...

Same SQL query WHERE search condition. Slightly different query value. Different performance. Why?...