How to optimize and reduce excessive database queries

1. How do you optimize a database?
2. Why is my SQL Query taking so long?
3. How do I optimize a query in MySQL?
4. How do I optimize SQL queries in WordPress?
5. How do you optimize a query?
6. Which database is fastest?
7. How can I speed up a slow SQL query?
8. Is view faster than query mysql?
9. How do I check SQL performance issues?
10. Do Joins slow down query?
11. How do I optimize a SQL query count?
12. What is query optimization with example?

How do you optimize a database?

1. Proper indexing. Index is basically a data structure that helps speed up the data retrieval process overall. ...
2. Retrieve the relevant data only. ...
3. Getting rid of correlated subqueries. ...
4. Using or avoiding temporary tables according to requirement. ...
5. Avoid coding loops. ...
6. Execution plans.

Why is my SQL Query taking so long?

There are a number of things that may cause a query to take longer time to execute: ... Table lock - The table is locked, by global lock or explicit table lock when the query is trying to access it. Deadlock - A query is waiting to access the same rows that are locked by another query.

How do I optimize a query in MySQL?

Optimize MySQL COUNT (*) query

1. SELECT COUNT(*) from table1 WHERE field1 IN ('val1','val2') OR field2 IN ('val3','val4'); ...
2. ALTER TABLE table1 ADD INDEX `field1_field2_idx` (`field1`,`field2`); ...
3. ALTER TABLE table1 ADD INDEX `field2_idx` (`field2`);

How do I optimize SQL queries in WordPress?

WordPress can be prone to slower queries on the wp_posts table, if you have a large amount of data, and many different custom post types. If you are finding querying for your post type slow, then consider moving away from the custom post type storage model and to a custom table.

How do you optimize a query?

It's vital you optimize your queries for minimum impact on database performance.

1. Define business requirements first. ...
2. SELECT fields instead of using SELECT * ...
3. Avoid SELECT DISTINCT. ...
4. Create joins with INNER JOIN (not WHERE) ...
5. Use WHERE instead of HAVING to define filters. ...
6. Use wildcards at the end of a phrase only.

Which database is fastest?

Cameron Purdy, a former Oracle executive and a Java evangelist explains what made NoSQL type database fast compared to relational SQL based databases. According to Purdy, for ad hoc queries, joins, updates, relational databases tend to be faster than “NoSQL type databases” for most use cases.

How can I speed up a slow SQL query?

Below are 23 rules to make your SQL faster and more efficient

1. Batch data deletion and updates. ...
2. Use automatic partitioning SQL server features. ...
3. Convert scalar functions into table-valued functions. ...
4. Instead of UPDATE, use CASE. ...
5. Reduce nested views to reduce lags. ...
6. Data pre-staging. ...
7. Use temp tables. ...
8. Avoid using re-use code.

Is view faster than query mysql?

No, a view is simply a stored text query. You can apply WHERE and ORDER against it, the execution plan will be calculated with those clauses taken into consideration.

How do I check SQL performance issues?

Start by checking your wait stats

1. Ensure your TempDB database is configured optimally. ...
2. Make sure you're running index maintenance frequently. ...
3. Implement indexes that provide a benefit to your queries. ...
4. Check your most expensive queries and stored procedures. ...
5. Monitor your performance counters.

Do Joins slow down query?

Joins: If your query joins two tables in a way that substantially increases the row count of the result set, your query is likely to be slow. ... Aggregations: Combining multiple rows to produce a result requires more computation than simply retrieving those rows.

How do I optimize a SQL query count?

select t.name as type, count(p. product_id) as n from file_item p inner join family f on f.id = p. family_id inner join type t on f.
...
There are 3 indexes on *file_item* table:

1. product_family_idx (product_id, family_id)
2. family_idx (family_id)
3. product_idx (product_id) Explain output :

What is query optimization with example?

Query optimization is a feature of many relational database management systems and other databases such as graph databases. The query optimizer attempts to determine the most efficient way to execute a given query by considering the possible query plans. ... A query is a request for information from a database.