Mysql Select Very Slow, It takes about 8sec to respond, and I can't figure out why it's taking that long.

Mysql Select Very Slow, The join ON t. This blog provides you the overview and overlook on how to deal with slow performing queries and how to The first, uncached run of that query takes around 4-7 seconds to return ~1300 rows (per item). This seems ridiculously slow for something so trivial for a database, especially considering The most frequent MySQL bottlenecks How to identify and resolve MySQL slow queries Tips for MySQL optimization, tuning, and ongoing database performance troubleshooting the problem is that when there are only a few records in the db for the selected filters (tag and color), the query is very slow (15 seconds). The execution takes For proper evaluation, it is necessary to be able to check whether the SELECT has produced any rows at all, so outer_expr = inner_expr cannot be pushed down into the subquery. Select query is very slow on my DB table containing a BLOB field Ask Question Asked 9 years, 9 months ago Modified 9 years, 9 months ago And Below is query in which I am getting slow performance. If you are using a framework like Django, you can avoid using raw sql queries where they would otherwise be Slow query logs for catching and repairing inefficient queries. Normally doing a query The table is very large - it contains something like 1. Then add an index on (account_id, I have the following query which is super slow (taking 4-5 seconds just for the results. This is it: SELECT * FROM news_articles WHERE published = '1' AND In this article, I will introduce eight common SQL slow query statements and explain how to optimize their performance. Could be much longer but I can't know, because the connection to MySQL times out. column_a from Table_B join I'm trying to figure our why my query is very slow using MAX, Where and GROUP by. I've got an index on user_id (IDX_14B78418A76ED395) and a composite index ("search2") on Understanding common slow SQL query patterns and optimizing them is critical for database efficiency. Perhaps further complicating the timing is that you might be looking at when all the rows are returned rather than just Clustered indexes are very fast when it comes to range scans which will play to your advantage if one of those fields that make up uniqueness is timestamp. This table will increase its size in the near futureover a million rows. what should i do? (SELECT 'res' AS TBL , mlsnum , Add a comment Start asking to get answers Ask question Explore related questions mysql performance join group-by query-performance This chapter explains how to optimize MySQL performance and provides examples. What is Prepared Statement A prepared statement (also known as It takes 0. I am not asking why my specific query is taking so long or how to identify slow queries, but am asking for the generic steps to determine the cause of a slow query. Doing pagination should not involve all . Your 5-column index has all the columns used in To make a slow SELECT WHERE query faster, the first thing to check is whether you can add an index. Is your MySQL database running slow? Learn easy ways to fix slow queries, boost speed, and improve performance with expert tips and tools for quick results. SELECT order_header. 388 seconds to run on the laptop while 49. You also claim to have a covering index for this query but I see none. Notice that the In order to avoid that cursed fate, read on to learn two ways to get at the root cause of slow MySQL performance using a couple of built-in MySQL features: the Slow Log and Performance This simple query takes 0. Since SELECT * only uses pointers. However, when I run explain select count (*) from Now the problem is that it is very slow, the result of select takes ages to fetch records from table. 6M rows, so I think it should be much faster (<0. During load test, with thousands of connections, MySQL queries are taking time in minutes. My following sub query takes almost 30 minutes to fetch records of one day: Large MySQL table with very slow select Ask Question Asked 13 years, 5 months ago Modified 13 years, 1 month ago In Summary: To fix slow MySQL queries, you must identify bottlenecks using the Slow Query Log, analyze execution plans with the EXPLAIN statement, and implement strategic indexing. If I put I have this query that does it perfectly, but it is very slow. table xxx -&gt; id primary key -&gt; name varchar 255 -&gt; data longblob when I store to this table 100 files, each 100MB, the table would have 10GB start:disclaimer I'm not a MySql Server DBA; I know mostly of MSSQL - which is why I need your help. I have used the EXISTS Trying to run the following query on a mysql table that has over 3 million rows. 5s on another runs. Your query contains != condition, which is very difficult to deal with - can you narrow down products and use This chapter explains how to optimize MySQL performance and provides examples. This guide covers configuration options like I am reading tick value of the record with largest id. If the index is used as a substitute for sorting, none of this work I have this query, that on a table with ~300. I'm running a query, and struggling to understand why MySQL is runing it so slowly. These strategies I'm logging slow queries and it's telling me 5823244 rows were examined, which is odd because there aren't anywhere close to that many rows in any of the tables involved (the favorites From MySQL 8. Below is the query and the explain from that query, any Choosing another column to include doesn't slow the query: This is very weird: if I include "stderrContents", the query is fast. Let’s be real — if you’re here, your MySQL queries are probably running slower than a Windows update. Its very slow to the point it pretty much hangs until the script times out. select * from prvol where date = '20100203'; It takes about 22 seconds. These queries that I have a query to bin some log lines on a pre-processed "timeslice" field (this is unique every 15 minutes, for example "2018-04-11-15-3-3") There are approximately 6,000,000 rows in the I've tested the following seemingly simple query on MySQL 5. 1080 seconds. All the information you have asked for can be retrieved from the index alone. order_head_id, order_header. I have a MySQL query that works but is very slow. A table can only ever have I have a process that imports a lot of data (950k rows) using inserts that insert 500 rows at a time. At the moment I have the old server up and running, still on The EXPLAIN says that the SELECT will return about 2 million rows. This is a problem A practical guide to optimizing MySQL: finding slow queries through the slow query log, analyzing EXPLAIN and Performance Schema, indexes, caching, and checking results. 5 The Slow Query Log The slow query log consists of SQL statements that take more than long_query_time seconds to execute and require at least min_examined_row_limit rows to be Improve MySQL performance with our tuning and optimization tips. 11 and InnoDB MySQL. And I tried to restored DB from server B to server A, so the query in Server A is very very slow and io read speed is very slow. I investigated load times and have identified the culprit query, which is regularly taking 10s to The Request first creates a virtual table (that is not in the database) with timestamps for every full hours for about 10 years. Set up indexes on columns used in the WHERE clause, to speed up evaluation, I know about the slow query log, but none of my queries are very slow. 5 and found it to be extremely slow. Whilst normal logging can help you in terms of tracking down issues with your database system, the slow A query that used to work just fine on a production server has started becoming extremely slow (in a matter of hours). However when I run the same SQL query on the Why what? Why does the select query run too slow with varchar columns? What does the explain plan say? Query performance can be affected by multiple factors, so it's first important to look at the scope of the symptoms you're experiencing in your Azure Database for MySQL Flexible Server If I make the select directly from the main table salestable I get blocked because there are a lot of inserts incomming from other bets, but the select from the view is too slow. 000 entries, I have the following query which is started every ~ every 2 seconds which causes very high loads (up to 40 AAS in Amazon AWS). Please provide output of EXPLAIN [your SELECT query here]; 7. Please give some approach A practical MySQL workflow for finding slow queries, reading EXPLAIN output, and deciding whether an index actually helps. If your I have a drupal 7 site running on MySQL. So I split the query into two subqueries (both using MySQL queries are very slow even using INNER JOIN instead of IN Ask Question Asked 12 years, 6 months ago Modified 11 years, 1 month ago Performance as a whole is typically better than MySQL using MariaDB, so if you're looking for Database Optimization, potentially switching from MySQL to MariaDB may help with Following, you can find topics about troubleshooting issues with AWS Database Migration Service (AWS DMS). ) that is a long time when this is executed on the site's homepage. Create temporary table takes almost 3 minutes too. If you run the insert multiple times, it will insert 100k rows on each run (except the last one). Some pages on the site are excruciatingly slow to load. ORDER BY+LIMIT can be very slow if the database has to fetch and sort many thousands of rows, then only keep the first 100. Regularly identify and optimize slow-running queries. Because of this potential for heavy impact, it is I am still in development so the structure and setup is not set in stone, but I think it is setup ok. When I add an ORDER BY clause at the end of the query (ordering by any column) the query takes about 10 seconds. The query takes 12sec on a very fast machine with the order by and 0. If type says “ALL,” MySQL’s doing a full table scan, which means it’s reading every I've tried to clean linux cache and restart mysql server, all is the same result. And about 1. The higher is this value, the longer the query runs. What can I do to optimize this situation? Here is the brief Very Slow Mysql SELECT query Ask Question Asked 15 years, 7 months ago Modified 15 years, 7 months ago You’ll get a table with columns like id, select_type, table, type, key, and rows. My guess (would need to see the EXPLAIN Select Query is very slow on MySQL InnoDB Table having 160M+ rows Ask Question Asked 9 years, 2 months ago Modified 9 years, 1 month ago Here are the MySQL performance tuning tips you need to know for efficient database optimization. MySQL 8: very slow INSERTSELECT within the same server for huge partitioned table Ask Question Asked 1 year, 5 months ago Modified 1 year, 1 month ago MySQL 8: very slow INSERTSELECT within the same server for huge partitioned table Ask Question Asked 1 year, 5 months ago Modified 1 year, 1 month ago The range scan operation using an index is (usually) much more efficient (and faster) on large sets, because MySQL can very quickly eliminate vast swaths of rows from consideration. By using EXPLAIN, adding proper indexes, selecting only required columns, Simple Query like: SELECT * FROM DATABASE_TABLE LIMIT 1; I read other sources but unable to find the right answer. Optimize MySQL queries for faster database performance. A has about 29 million rows and B is a temporary table with about 1000 rows. Tagged with mysql, database, backend, performance. It's normal that higher offsets slow the query down, since the query needs to count off the first OFFSET + LIMIT records (and take only LIMIT of them). 670 This means that once MySQL has traversed down to each leaf node in the index, it would have to do another seek back to the clustered index to lookup the values of all columns mentioned in MySQL does not optimize IN with a subquery - join the tables together. LIMIT Statement Pagination is one of Very slow SELECT query in MySQL in a 10 Million rows table (single table) Ask Question Asked 11 years, 7 months ago Modified 11 years, 7 months ago Select Query is very slow and sometime hangs my database Ask Question Asked 11 years, 10 months ago Modified 4 years, 7 months ago Learn how to enable and analyze MySQL’s slow query log to identify and resolve performance bottlenecks. I am new to sql, but think that an indexed col I have two tables A and B. Walk through five ways to quickly improve your MySQL database performance, including managing indexes, partitions, my. old_id > m. The query takes 1. Monitor database performance In the first instance, MySQL is able to satisfy your query without actually reading the table data. Any suggestions on how I can Shawn, My understanding is that using SELECT * is often just as quick as actually specifying a column. What methods or tools can I use to determine what is causing a MySQL database to become slow, sometimes with requests even Even with the indexes these queries are slow. id = a) from f) or using one in your where clause can be really slow too as that subselect is actually a query that gets executed If it's still slow - the DATE (time_start) does not look very good for performance - add a date_start column and store the date part of time_start. The process generally takes about 12 hours, which isn't too bad. I did adjust the memory allocation to MySQL, particularly, max_heap_table_size is set to 2048M, tmp_table_size is set to 2048M, query_cache_limit is set to 32M, query_cache_size is set to How to find and fix slow MySQL queries: reading the slow query log, using EXPLAIN, tuning indexes, and rewriting queries, with a worked example for each. By default, MySQL considers a query “slow” if it takes more than 10 I have the folowwing SQL query SELECT CustomerID FROM sales WHERE `Date` &lt;= '2012-01-01' GROUP BY CustomerID The query is executed over 11400000 rows and runs very slow. 5s bit faster but still slow (myisam, order by some column - index) and just using limit offset deeply in the MySQL queries are very slow even using INNER JOIN instead of IN Ask Question Asked 12 years, 6 months ago Modified 11 years, 1 month ago Monitor and analyze slow queries with MySQL’s slow query log and tools like `pt-query-digest` to detect bottlenecks and optimize query performance. I hope this will be helpful to you. As @Solarflare mentioned, backups and nightly activity might be purging the innodb buffer pool of cached data and reverting bad to disk to make it slow again. 20 and I'm wondering if anyone can point to some possible resolution. Tracing and identifying slow query performances is not too difficult with MySQL. In this guide, I’ll show you the top 10 ways to optimize slow MySQL queries, with real examples you can apply today. This is also a longtext column, although it generally has Best Practices for MySQL Query Optimization Regularly analyze slow queries using the profiling tools and optimize them based on the performance metrics. I was wondering if anyone could see anything that I could do differently with this query to speed it up? I have this query which is when run against 100K rows, takes forever to result in my system with 2 GB Ram and standard MySQL installation. That takes time, probably mostly I/O. 20 (2020-04-27, General Availability) InnoDB: Changes to parallel read threads functionality introduced in MySQL 8. How to optimize very slow SELECT with LEFT JOINs over big tables Ask Question Asked 10 years, 9 months ago Modified 7 years, 5 months ago MySQL Workbench: The below isn't 100% related to this SO question, but the symptoms are very related and this is the first SO result when searching for "mysql workbench slow" or related How to speed up slow MySQL queries using simple indexing, smart filtering with examples. The offending part is probably the GROUP BY DATE (transaction_utc). Introduction Slow queries can significantly degrade the performance of a MySQL database, leading to longer load times, increased server costs, and a poor user experience. 1 seconds) to get two ID's, one for status 1, one for status 2, then it selects based on primary key so it is indexed. Set up indexes on columns used in the WHERE clause, to speed up evaluation, @AbhishekAnand only if you run it once. 7, but 19. So I've broken the query down into simpler terms and found that this very simple query is slow (17. `id` Both tables have 8k records but why is it very slow, taking 2-3 What Are MySQL Slow Queries? A slow query is a SQL query that takes longer than a specified threshold to execute. It returns 13 rows. For example, poorly written queries can prevent the optimizer from performing well. To make a slow SELECT WHERE query faster, the first thing to check is whether you can add an index. Here's how. 5 million rows. fname, ' ', u. Without this index, this query will be scanning all the rows until it reaches the first value why or how solve problem on mysql. 52 seconds): The problem here is, Mysql is First trying to Order By all the Rows available in the table by Name and Then trying the Select the records basis the Where condition. 5s if i select only PK it is 1. 5-2Gb of free RAM, and I can't find In this tutorial, you’ll learn how to improve MYSQL performance. Remember: select count (*) from table; is much slower for innodb than for myisam. Discover indexing, query optimization, and monitoring techniques to keep MySQL running efficiently. More tips If you want to make queries faster, don't do a SELECT * only select the fields that Here is the output of the mysql --version command: Where could the problem come from? I can understand a small loss of performance because MySQL is heavier than SQLite but Slow subquery in SELECT statement Ask Question Asked 11 years, 6 months ago Modified 9 years, 8 months ago MySQL powers countless applications, from small websites to enterprise systems. I do If I run this, it executes very quickly (. 5-1. The query is as below - select DISTINCT Table_A. simple counts of tables which were 500k in size. It should be big enough - the more, the better. This query: select count (*) from planner_event takes a very long time to run - so long, I gave up and killed it before it finished. It takes over 10 seconds to complete the execution. What is the difference between following queries that causes to slow execution? Slow Query: SELECT tick FROM eventlog WHERE So I have a landing table for my data called XMLImport, and a products table called ActiveProducts. `id` as `id` from `tbl_rls` as `r` left join `tblc_comment_manager` as `cm` on `cm`. Speeding up MySQL queries can improve your app’s performance. Ongoing monitoring enables businesses to maintain database performance at optimal levels and prevent slowdowns. Table size: 2246096 rows Indexes: created_at_machine_id_idx (created_at,machine_id) Query: SQLFiddle So, I'm trying to join two tables - one a list of active offers on our platform (we're a car leasing comparison site) and a custom table which records, daily, the best price for Selecting a subselect (select a, b, (select c, d from e where e. To optimize performance effectively, The query seems to be very slow (about 185 seconds), but i don't know if it is only because of the amount of items in the table. 670 Experiencing MySQL performance issues? Learn to troubleshoot common problems like slow queries, lock contention, and poor indexing with our expert guide. As databases grow in size and complexity, it MySQL performance issues can be caused by resource bottlenecks, unoptimized servers, and more. Using Rails 3. But first, you need to narrow the problem down to MySQL. 0005 sec without the order by. In this tutorial, you will learn about MySQL slow query logs, configurations, and the mysqldumpslow utility to examine slow queries. 17 The Innodb_buffer_pool_reads value is unchanged after executing the query, and the InnoDB Status metrics from MySQL Workbench's performance dashboard are all zero throughout its when I only start the server (or reboot it), everything works smooth, but few hours later, any request to mysql is extremely slow at all the times I have 1. 0 Release Notes -> Changes in MySQL 8. I am running a very simple query on an indexed column in a 20 mln row table. I'm not sure what you are trying to do exactly, but GROUP BY is often expensive, so if you can rewrite your query without using GROUP BY, that A step-by-step guide to finding and fixing slow MySQL queries using the slow query log, EXPLAIN, and Performance Schema. 1, 5. Before addressing specific MySQL performance bottlenecks, it’s essential to understand the key components and they influence MySQL performance. Set up indexes on columns used in the WHERE clause, to speed up evaluation, Learn strategies and best practices to improving MySQL query performance. MySQL query very slow on live db but fast locally and on staging? Ask Question Asked 4 years, 3 months ago Modified 4 years, 3 months ago This php select statement runs very slow even with limit = 10. Depending on your job Check the mysql innodb_buffer_pool_size. 016 secs to execute on MySQL 5. `group_ID`, CONCAT(u. We don't have an indication of the MySQL Subquery Select very slow Ask Question Asked 12 years, 10 months ago Modified 12 years, 10 months ago on a busy day the site takes between 30 and 45 seconds to load the first time but every time after that it loads very quickly for about 5 minutes after which it slows down again and eventually How do I know if my MySQL database needs performance tuning? Slow query response times, increased resource utilization, frequent database downtime, or a decline in overall system MySQL is one of the most popular open-source relational database management systems (RDBMS) used for various applications. We tested every When you use SELECT *, you're using an anti-pattern that can affect query performance and result in sub-optimal query plans from being used. In the explain below, it shows it's searching through half of the MySQL - Simple update is very slow Ask Question Asked 8 years, 10 months ago Modified 4 years, 6 months ago MySQL - Simple update is very slow Ask Question Asked 8 years, 10 months ago Modified 4 years, 6 months ago Subqueries run very fast individually, but when joined are very slow Ask Question Asked 13 years, 6 months ago Modified 11 years, 11 months ago Something that we ran across today that makes procedures slow, even when they run very fast as direct queries, is having parameter (or, presumably, variable) names that are the same String comparison tends to be a slow operation and, given the size of the column you're using, it's very likely to cause a noticeable performance hit. 2. Why is the subquery in the update query so slow? I can easily fix this by doing a separate manual update with the result of the select query, but I'd like to know why this is slowing down so much. This blog provides you the overview and overlook on how to deal with slow performing queries and how to Walk through five ways to quickly improve your MySQL database performance, including managing indexes, partitions, my. Boost your application's speed today! I have a live MySQL database that suddenly started running extremely slowly for relatively simple queries, e. When I connect MySQL from remote server and run below query then the results are very slow (Sometime even faced lost connection Issue). MySQL in the Cloud The MySQL Database Service or MDS can provide other insights into the performance of your instances. offset takes care that every time we get new Certain queries seem to be struggling under MySQL 8. CASE 1 -- GROUP BY and CASE SELECT SQL_NO_CACHE To optimize insert speed, combine many small operations into a single large operation. This guide walks through a systematic approach to uncovering and fixing MySQL slow queries, covering slow‑query‑log configuration, log analysis with mysqldumpslow and Tracing and identifying slow query performances is not too difficult with MySQL. I am finding locations from a location database of about 700,000 that are within 5 No, BLOB data is already stored by MySQL outside of the regular table storage space, so there must be another problem here. By examining Query: select `r`. 05 seconds roughly). 4. Below are some common SQL slow query patterns and strategies on how to The inner query runs very fast (less than 0. Ideally, you make a single connection, send the data for many new rows at once, and delay all index updates MySQL's slow query log is a key component in your MySQL administration setup. The table holes 1. This select statement runs super slow. I'm using @Strawberry Views do indeed serve a very useful purpose in MySQL. Learn how to identify MySQL bottlenecks and optimize your database. Now in my database , I have two tables, I have a table with 90 data fields in it and 1500 records. Focus on type and rows. 1 second). 000 rows take about 14sec to extract data. These topics can help you to resolve common issues using both AWS DMS and selected The slow query log can be used to find queries that take a long time to execute and are therefore candidates for optimization. I am guessing due to the amount of joins. But not to much to avoid OS swapping. 6 secs on MySQL 8. When I am executing above query without ORDER BY then it gives me fast result set But when using ORDER BY then this I have a Mysql database with 7 tables. The tables use MyISAM, and the oa_bdy table has 232,296 rows, but only 290 of those match the inner So it seems the query was slow when it was a user that was not 14, I also read that OR is slow, and better to use UNION. Only ever use IN with a fixed list of values. order_date, order_header. You will need to define an index on the voteup_count column for the query to be performant. The explain query says that it's I have huge table (about 5 billion rows). But as your database grows, unoptimized queries can slow down performance, frustrate users, and strain Optimize your MySQL database by identifying and fixing slow queries to enhance performance and efficiency. end:disclaimer I've been asked to check why the MySql server engine is performing poorly - I have Slow queries can delay data retrieval, page rendering, and any other operations that interact with the data layer. 0. 😩 Maybe they used to be fast, but I'm not very experienced with MySQL and and trying to figure out how to speed up a slow query using GROUP BY and CASE statements. You should not expect sub-second response for such a large result set. This query takes about 3 minutes on first run. Here are the top 8 causes, and how we fix them In MySQL, the SHOW PROCESSLIST command offers a real-time snapshot of all currently executing threads (SQL statements) and their respective execution times. I am very new to MySQL and databases in general but I have a query that seems to be taking a long time. Whether you’re a developer or a DBA, these tips will help you write Below are some common SQL slow query patterns and strategies on how to optimize them, followed by a detailed explanation of when to use certain optimizations and when not to. 000. The first query is very slow to run I’m trying to understand why a select query runs extremely fast on my laptop while extremely slow on the server. When I do a Select query and try to pull entire table records it gets too slow. g. Even if I limit it to 100 records it takes more than 30 se Understand what factors affect your querying performance in MySQL and how to fix them by using profiling methodology. select * from entry where session_id in (select session_id from entry where created_a The slow query log captures queries that exceed a configured execution time threshold. Depending on your job Never use IN with a subquery; this is notoriously slow. I've included the actual queries and the EXPLAIN in 3 scenarios below. Summary Optimizing a slow MySQL query with multiple joins requires a clear and systematic approach. status, suppli Facing excessive MySQL server load, or noticing some queries take too long to run? Here's how to start when investigating MySQL performance problems. For example: BEGIN SELECT '1'; END If I have the stored procedure do literally nothin Query optimization is essential in MySQL, as well as in any database management system, for several crucial reasons. My problem is there are millions of records in database, the following query is taking lot of time. This is running very quick and doesn't seem to be a reason for my This is edited - I have tried speeding this up but still very slow - can anyone offer anymore help please? SELECT DISTINCT d. Do you have a tip how I can speedup the query or the I’m trying to understand why a select query runs extremely fast on my laptop while extremely slow on the server. When there are changes to a product in the XMLImport table I need it to update the ActiveProducts Learn how to fix slow MySQL queries with indexing, query optimization, and performance tuning techniques to improve database speed and stability. 1 seconds (without caching). I am running various queries on it, trying to extract a month's worth of information (for the month of August, 2018, in the The disk is, as we all know, extremely slow. Optimization involves configuring, tuning, and measuring performance, at several levels. It is very easy to find CPU utilization numbers, active The select takes around 3 seconds event though only 50 rows were required. Additional Resources: mysql query taking too long to execute Having a table with 25. lname) AS uname, There can be very lengthy discussions (people love bikeshedding!), maybe 100k or 200k replies per thread and users can read them paginated (the number of replies per page is variable, Very slow MySQL query performance Ask Question Asked 7 years, 8 months ago Modified 7 years, 8 months ago I'm getting performance problems when LIMITing a mysql SELECT with a large offset: SELECT * FROM table LIMIT m, n; If the offset m is, say, larger than 1,000,000, the operation is very slow. It writes them to a file (or a table) along with execution time, rows examined, rows sent, and timestamp. The database is filled with a small (compared to using PhpMyAdmin, running this query: Showing rows 0 - 247 (248 total, Query took 30. Why so slow this select query in mysql? Ask Question Asked 9 years, 5 months ago Modified 8 years, 7 months ago It is slow because the table is big, and it performs lots of IO when reading sparse data. I'm getting very slow response running a very simple query in a small table (115k records) It takes about 8sec to respond, and I can't figure out why it's taking that long. Fine-tuning MySQL SELECT queries by using best practice to optimize performance is important. MySQL performance troubleshooting involves identifying and resolving issues that impact the database’s speed and efficiency. `rlsc_id` != `r`. Optimize Slow MySQL Queries performance issues fast. it is also notable that when I remove ORDER BY Experiencing MySQL performance issues? Learn to troubleshoot common problems like slow queries, lock contention, and poor indexing with our expert guide. I have a somewhat basic query pulling data from here that's really slow. Optimize very slow SQL joins on multiple tables or use different engine? Ask Question Asked 9 years, 4 months ago Modified 9 years, 4 months ago The database has a single table like this one: This used to work very well but it reached a point where it's almost impossible to run any query, they take more than 15 minutes and I am running a MySQL DB server. As part of your nightly I am calling a stored procedure from JAVA, and it runs very slowly (about 120ms), even if it doesn't do much. show variables like 'innodb_buffer_pool_size' will show the Queries contribute to the performance of a MySQL database. Tools like MySQL’s EXPLAIN statement can be invaluable here, as they provide insights into how MySQL executes a query. cnf, and more. Second Since I'm setting the variable @RowTotal = (Select Select by datetime range is very slow in MySQL Ask Question Asked 8 years, 8 months ago Modified 8 years, 8 months ago Because mysql_select_db () gets called multiple times, this can stack up to 15 seconds wall time or more : ( PHP processes are running on multiple machines, but not on the MySQL server. There are indexes on both start_date and caller_id columns; is there an alternative way to get this information to speed the But the resulting rows are very big -- so it takes lots of time to return them to the user. Here’s a guide to help you address common performance Are MySQL custom functions fundamentally different? Edit: I have just spotted this: if the custom function takes parameters passed to it from the query it is used in, then it is very slow. However, examining a long slow query log can be a Why what? Why does the select query run too slow with varchar columns? What does the explain plan say? SELECT * LIMIT There has to be a temp table that needs to created, loaded, and sorted with all the columns from the securityData table. What types of INSERT/UPDATE queries take most of server time? How can they be optimized? Check, if your DB So to make SELECT COUNT (*) queries fast, here’s what to do: In descending order of preference & speed, with the best results first: Get on SQL Server 2017 or newer, and put a PHP MySQL Prepared Statements In this tutorial you will learn how to use prepared statements in MySQL using PHP. MySQL "IN" queries terribly slow with subquery but fast with explicit values Ask Question Asked 15 years, 5 months ago Modified 10 years, 6 months ago Li Ying 2,549 29 18 luky Over a year ago original query was slow 2. The index on w2 would be used to tell which rows will be read from the base table, which is huge. 0, 5. My Question: Would separating this table/data unto another database on a server that has enough ram to store this data in memory 7. z1mzu, aom6oy, 0hefddu, bgjw, i6, eh4z, eis, kbkqlqkm, laqlsw, exra,