How to Optimize Database Queries

Optimizing database queries is essential to raising your website or application’s performance.

Indexing

One of the best methods for optimizing query performance is indexing. The database engine can find and retrieve particular rows considerably more quickly thanks to indexes. The columns indexed should be used in ORDER BY clauses, JOIN conditions, and WHERE clauses.

Efficient Queries

Write your SQL queries with care. Use aliases for tables to make queries easier to comprehend, just select the columns you need, and avoid SELECT *, which retrieves all columns.

SELECT DISTINCT

Utilizing SELECT DISTINCT may use a lot of resources. If at all possible, look for different approaches that don’t include DISTINCT to get the intended effects.

Joins

Be aware of how you employ JOIN operations. Steer clear of pointless joins and employ the join type that best suits your demands (LEFT JOIN, INNER JOIN, etc.). Make that the connected columns are correctly indexed as well.

Number of Rows Returned

Use the LIMIT clause to restrict the number of rows returned by a query. This is especially helpful for searches that do not require retrieving every entry that matches.

SELECT * FROM your_table LIMIT 10;

GROUP BY and ORDER BY

Be cautious when utilizing GROUP BY and ORDER BY clauses, as they might be resource-intensive. Make sure the relevant columns are appropriately indexed.

Subqueries

Subqueries may be ineffective if they are used for every row, in particular. To get the same result without utilizing subqueries, try rewriting queries using JOINs or other techniques.

Optimize WHERE Clause

Write your WHERE clauses with as much specificity as you can. Utilize the proper operators; functions on indexed columns should be avoided as they may interfere with the use of indexes.

Analyze Query Performance

Utilize database profiling tools for performance analysis and monitoring of queries. Determine which queries are sluggish and improve them using the information the profiling tools have to offer.

Database Caching

Implementing a caching system for queries that are used frequently can greatly enhance performance. Database caching solutions or application-level caching could be used for this.

Statistics

Maintain current database statistics. The query optimizer can make improved decisions about query execution with the use of updated statistics.

Database Sharding

To disperse data across several databases or servers for large-scale applications, take database sharding into consideration. By doing so, the load may be distributed and performance can be raised overall.

Database Design

Make sure the normalization of your database is correct. This can decrease duplication and increase query efficiency.

Before introducing any changes into a production environment, see how they affect a development or staging environment. The ideal technique may differ based on the individual database system you’re using (e.g., MySQL, PostgreSQL, SQL Server).

Client Reviews

Declan Clifford – Founder Launch Local – USA.

Came through for us on database work and completed it quickly.

Scott Malin CEO at Malin Method – USA.

Ted is one of those rare contractors that is a real expert in his field and delivers incredible results. Instead of just lazily installing a caching plugin, he took the time to really understand our websites (which were complicated – WP multi-sites with back end member software). This was crucial, because the cookie cutter approach would not have worked. Theodoros worked through the optimization process carefully until we had blazing fast websites with great scores. I am grateful we found him and HIGHLY recommend him to anyone looking to optimize their websites.

Steven Daniels CEO at Black Lotus Audio – USA.

Great work, will absolutely use Ted to speed up all my future websites! Very good communicator and delivered stellar results. Even went back a few times to fix little issues that I found such as certain pages or elements needing to be excluded, etc. Ted took my site from ~50 to nearly 100 on all pages as measured by Pagespeed insights. All around I had a great experience and highly recommend Ted to anyone with a WordPress site that they want sped up! The usability of my website increased and so did my revenue. Another huge plus was his communication was very professional and he even fixed a few extra issues that we ran into along with way like a pro. If you want your site sped up, Ted is your guy.

Kasper Van Ling CEO at Welten Tanzer – Indonesia.

Ted is a great catch. He does the job professionally and solves every problem thrown at him. Very much recommended. I will hire him again in the future if I need him.

Nikko Karki CEO at Indoyachts – USA.

Ted is one of the absolute best developers we have had the pleasure of working with. We came to Ted with a problem that we had tried solving with other developers, but had hit a wall. It was clear during the interview process that Ted knew his subject matter on a much deeper level than all the other applicants. The tasks were completed well beyond our expectations, with a lot of free technical advice and help that is worth much more than what we had agreed on for this project. The hours were billed in the fairest way and it really made this an easy and positive experience. Suffice to say, we will be in touch again soon with more projects to work on together. Thank you so much for your positive contribution to our website.

Ching Foo Lieu CEO at How to Finance Money – Malaysia.

Ted is a Rockstar when it comes to Page Speed optimization. My website speed spiked in leaps and bounds after experiencing Ted’s magical touch – mind-blowing to say the least. I’ve engaged different so-called ‘experts’ in the past but all they did was band-aid solutions. Ted is refreshingly different. Initially I was skeptical, until I saw the speed metrics literally fly. He also went above and beyond to fix/optimize other related areas which I overlooked or didn’t even know. A knowledgeable technical professional like Ted deserves the rate he asks for, so while you may be able to get ‘cheaper’ rates from others, end of the day, ask yourself whether you are looking for result or cheapest freelancer. Money well spent – I vouch for him.

FAQ related to DB Projects

Can I keep editing and working the content while the Database cleanup is running?

NO. You will need to pause all content edits and any changes to the frontend till the end of this project.

Is the work done on the live website?

The database cleanup work is done on the live (production) website and in the respective database on the server. If it is an e-shop it is nearly impossible to copy the work and a staging website won't keep any new orders coming in during the work. Plus, there may be lack of available disk space to create a test clone (staging).

How to assess the success of the project?

The database response time or database query time will be measured for the most important pages before starting the work and upon delivering the work using accredited monitoring tools that report those metrics, so both parties can compare the progress made upon delivery.

What if I have server errors?

If your server produces 502 errors or has database connection issues I can't give any guarantee that they will be fixed. 502 errors are server errors, and database connection errors originate from faulty MySQL setup on the server, which is a host’s responsibility and liability, as to the reasons they are generated they could be due to unclear factors besides a large database or script installation.
I will optimize the server and clean up the database the same way I do for large e-shops and the delivered database will show whether those errors are reduced or gone. The final payment will not depend on the existence of 502 errors neither database connection errors, as the contract has a limited scope (database cleanup) and the work might, or might not, fix those errors and there will be no guarantee given for those. Feel free to find a dedicated developer as well a server specialist who can fix those errors BEFORE starting the contract.

How safe is the database cleanup?

The database cleanup work has been proven very safe in the 100% of previous database works. Backups will be taken (website and database provided there is enough server disk space), besides any server backups that are automatically running daily or on any other period. I cannot be responsible for any failures attributed to the host to restore backups kept in the host control panel backup tool or elsewhere on the server. It happens sometimes that backups cannot be pulled from the host either because they don’t offer that functionality (e.g. Siteground) or they don't allow their clients to restore from local backups. Host backups are not always reliable (they break or stop due to short intervals set by the host to run scripts) so the backup restore function fails. Bottom line, I will not be deemed responsible for any failures attributed to the host to restore backups kept in the host control panel backup tool or elsewhere on the server.

What is your database method?

I will follow the proven successful method below:

Scope: make the database scalable, lean, and fit to respond faster to queries. The positive effects can be seen immediately, the site renders the pages more quickly, and the speed score is higher.

Areas to optimize:

- The primary technique to improve scalability is to fix performance so that it does not degrade as your site grows.

- Fix slow queries as the site gets bigger

- Fixes the issue of too many queries. This problem most often comes from badly coded search or filtering plugins.

- Fixes the issue of having too much RAM and CPU consumption in PHP.

- Remove the clutter from the database that plugins leave behind when removed.

- Creates indexes and helps the database respond faster to queries.

- Rationalize the autoload table as instructed here: https://wpengine.com/support/database-optimization-best-practices/#Autoloaded_Data

- Removes Woocommerce clutter.

- Reduces those multiple (unnecessary) calls to the database that website themes and plugins do.

Will you provide a list with the actions taken?

No timelog of any actions taken in the database will be shared as there is no way to revert the work done in the database due to the nature of MySQL Databases. A generic list of actions taken in similar projects will be shared and you can read it in the answer above. And as a backup will be shared prior to starting the work that enables you to restore the database if you feel the cleanup is not needed anymore. In this last case an hourly compensation will be due.

Is there a Refund?

No refund will be given for working hours spent to clean up your database. If you wish to cancel the project you won’t be entitled to a refund and you are free to restore the backup shared from me prior to starting the work. That said, the working hours in the event of canceling the project following your wish, will need to be compensated at an hourly rate of $67 per hour.

Specifically, you are responsible to take the initiative to contact me and agree together on how the hourly compensation is to be paid.

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