1 Optimizing SELECT Statements. This document gathers together links to the relevant documentation, and adds various tips, organized under a number of headings that outline the steps to take when attempting to optimize your database usage. Summary Mastering MySQL Explain is a valuable skill for optimizing your database queries. While Amazon RDS accepts the OPTIMIZE TABLE command Aug 2, 2018 · To optimize the above query, we can just add an index to the 'customer_id' field using the below syntax: mysql> Create index customer_id ON customers (customer_Id); Query OK, 0 rows affected (0. What you should do is measure before, do an optimization and then measure after. Behind the scenes, it uses the CHECK TABLE, REPAIR TABLE, ANALYZE TABLE, and OPTIMIZE TABLE statements. As you work on database performance, you start by Feb 27, 2024 · MySQL OPTIMIZE TABLE. I'm running mysql 5. OPTIMIZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name [, tbl_name] OPTIMIZE TABLE reorganizes the physical storage of table data and associated index data, to reduce storage space and improve I/O efficiency when accessing the table. It might have some meaning for INPLACE algorithm of alter in newer MySQL versions, but it would be better do the normal alter instead in the first place. 18 introduces EXPLAIN ANALYZE , which runs a statement and produces EXPLAIN output along with timing and additional, iterator-based, information about how the optimizer's expectations matched the actual execution. To coalesce fragmented rows and eliminate wasted space that results from deleting or updating rows, run myisamchk in recovery mode: $> myisamchk -r tbl_name. spEmployee. 12 Optimizing the MySQL Server. If a query is stored and then an identical query is received in the future, it will return results much faster. Dec 29, 2023 · First, provision a MySQL DB System in Oracle Cloud Infrastructure (OCI). Find Tables for Optimization. Dec 9, 2010 · Why you shouldn’t necessarily optimize tables with MySQL OPTIMIZE. This lets one check how close the optimizer's estimates about the query plan are The mysqlcheck is a command-line utility provided by MySQL to check, repair, analyze, and optimize tables in MySQL server. Also, as each replica must receive a full copy of the source's binary log, the network load on the source may also increase and create a bottleneck. Feb 1, 2010 · 10. Check Tables for Optimization. SELECT * vs. 18 we can use EXPLAIN ANALYZE to get EXPLAIN output along with timing and additional, iterator-based, information about how the optimiser’s expectations matched the actual execution. Chapter 10 Optimization. Before you do optimization, first confirm whether your MySQL database is suffering from fragmentation or not. Queries, in the form of SELECT statements, perform all the lookup operations in the database. This can result in huge improvements by reducing the amount of data written to and read from disk. The message that says "Table does not support optimize, doing recreate + analyze instead" is purely informational. By default, an OPTIMIZE TABLE will defragment a table. 26. "Table does not support optimize, doing recreate + analyze" -- Just a warning; ignore the harsh tone of it. 4 supports an additional INTO option with EXPLAIN. Jun 20, 2009 · OPTIMIZE TABLE does a table repair and a key analysis, and also sorts the index tree so that key lookups are faster. Sep 4, 2023 · Always analyze the Explain output to identify potential bottlenecks and areas for improvement. This will analyze the table and make changes to improve performance. 3. Any space reduction for table data also 9. MySQL Workbench includes various tools for both DBAs and Developers related to viewing and improving performance. The core logic of a database application is performed through SQL statements, whether issued directly through an interpreter or submitted behind the scenes through an API. This process can be a lot faster, especially for large indexes which would get inserts in very random order ANALYZE TABLE without any HISTOGRAM clause performs a key distribution analysis and stores the distribution for the named table or tables. Description. #4 and #5: Indexes and partitions. In MySQL 8. 8. Example of a stored procedure: CREATE PROCEDURE dbo. (This is a long discussion that I have tackled in other Questions. The EXPLAIN output will be annotated with statistics from statement execution. 1. It lists the tables in the output in the order that MySQL would read them while processing the statement. 1 Optimizing Data Size. As the number of replicas connecting to a source increases, the load, although minimal, also increases, as each replica uses a client connection to the source. 1 Optimizing Queries with EXPLAIN. In the process, MySQL determines what indexes to use for the query, what join algorithms, sorts lists of constants in in lists, and much more. EXPLAIN ANALYZE. Mar 9, 2023 · The EXPLAIN statement is a powerful tool that developers can use to analyze and optimize MySQL queries. In this article, we examined the various columns in the EXPLAIN statement output. This is because MySQL has detected that the underlying table has changed and it needs to close and reopen it using FLUSH. This statement requires SELECT and INSERT privileges for the table. Optimizing for the wrong value causes fragmentation with secondary indexes. Jun 24, 2021 · Analyze which value benefits from compacting the most. If you select all records from small tables and send it to app then you do not need to actualize statistics. Jul 4, 2014 · 1. analyze should be redone whenever the overall distribution of the indexed data changes significantly. You need to analyze which table is consuming more space in your database. If you see note : The storage engine for the table doesn't support repair it means that you are doing REPAIR on an InnoDB. 2 Optimizing SQL Statements. We can use EXPLAIN ANALYZE on SELECT and TABLE statements, as well as with multi-table UPDATE and DELETE statements. Smaller tables normally require less main memory while their contents are being actively processed during query execution. This guide explores how to efficiently analyze a table in MySQL, an essential task for database engineers to ensure smooth data retrieval and storage processes. Jun 24, 2015 · InnoDB does not support optimize, so does an "empty" alter table instead. EXPLAIN works with SELECT , DELETE , INSERT , REPLACE, and UPDATE statements. 15. This selection is critical to enable HeatWave features. mysql : optimize table, analyze table, check table and repair table commands This article describes some common table maintenance operations in MySQL. Mar 29, 2011 · MySQL has an OPTIMIZE TABLE command which can be used to reclaim unused space in a MySQL install. AS. OPTIMIZE TABLE works for InnoDB, MyISAM, and ARCHIVE tables. Oct 1, 2018 · For Aurora with MySQL compatibility and RDS MySQL, you see the load subdivided by MySQL Performance Schema wait events. When EXPLAIN is used with an explainable statement, MySQL displays information from the optimizer about the statement execution plan. Example: Jun 4, 2015 · The message you are getting is basically MySQL server repeating what the InnoDB storage engine told MySQL server: Table does not support optimize is the InnoDB storage engine saying "I (the InnoDB storage engine) don't do an OPTIMIZE operation like my friend (the MyISAM storage engine) does. For each iterator, the following information is provided: Estimated execution cost. It's a read-only action, it just reads a random The ANALYZE statement is similar to the EXPLAIN statement. When execution finishes, EXPLAIN ANALYZE will print the plan and the measurements 15. 9 Controlling the Query Optimizer. If you just did an alter changing structure of the table, then optimize is meaningless. Start by connecting to your MySQL database: use Sep 29, 2016 · Mysql optimize to avoid table scan. ANALYZE TABLE t DROP HISTOGRAM ON c2; The first statement updates the histograms for columns c1, c2, and c3, replacing any existing histograms for those columns. As mentioned above, views do not reside in your DB but are rebuild every time. mysqlcheck uses the SQL statements CHECK TABLE , REPAIR TABLE , ANALYZE TABLE, and OPTIMIZE TABLE in a convenient way for the user. Apr 25, 2016 · This tutorial explains how to optimize MySQL to defrag tables and reclaim unused space. 3. Is it not possible to optimize without recreate in this Mar 23, 2010 · When you run OPTIMIZE TABLE against InnoDB tables it outputs the Table does not support optimize, doing recreate + analyze instead message. This chapter explains how to optimize MySQL performance and provides examples. They 15. Step 3: Use the OPTIMIZE function that is provided by MySQL and use it on the table that we need to optimize. MySQL. The table rebuild triggered by OPTIMIZE. Using these parameters, an approximate formula for estimating ANALYZE TABLE complexity would be: The value of innodb_stats_persistent_sample_pages * number of indexed columns in a table * the number of partitions Aug 6, 2014 · The MySQL approximation of PostgreSQL's vacuum is OPTIMIZE TABLE tablename ( MySQL docs ). OPTIMIZE TABLE does a table repair and a key analysis, and . With the tool, you can improve performance, stay up-to-date on releases and bug fixes, manage and avoid any problems or downtime, and optimize how things work. By consuming each engine type’s native wait event instrumentation for wait events, Performance Insights is can keep a similar look and feel across engine types while remaining faithful to each engine’s native performance Apr 4, 2020 · For InnoDB, the actions performed by ANALYZE TABLE are also performed by merely viewing the table status, if the option I show above is ON. Optimized MySQL configurations can decrease server CPU utilization by up to 50%, resulting in lower operational costs. In the SQL Editor view, locate and click on the create schema button: An arrow pointing to the button you click to create a new schema in MySQL Workbench. optimize table doc. Jul 26, 2021 · It will plan the query, instrument it and execute it while counting rows and measuring time spent at various points in the execution plan. This process can help improve performance by reorganizing how data is stored and accessed. oci mysql db-system create --display-name myHeatWaveDB . 4 MyISAM Table Optimization. When execution finishes, EXPLAIN ANALYZE will print the plan and the measurements instead of the query result. An exclusive table lock is only taken briefly during the prepare phase and the commit phase of the operation. ANALYZE statement will invoke the optimizer, execute the statement, and then produce EXPLAIN output instead of the result set. EXPLAIN returns a row of information for each table used in the SELECT statement. 4 Maintenance of Partitions. Use this command before executing a query to analyze its execution plan, identify potential bottlenecks, and change the query accordingly. Yes. Django’s database layer provides various ways to help developers get the most out of their databases. Feb 12, 2024 · Optimization Steps. Feb 21, 2024 · You can execute this command through any MySQL client. #1: Managing the my. Instead, the OPTIMIZE TABLE statement performs the following actions: First, create a new empty table. ANALYZE TABLE analyzes and stores the key distribution for a table ( index statistics ). Tuning these statements is a top priority, whether to achieve sub-second response times for dynamic web pages, or to chop hours off the time to generate huge overnight reports. Identify Tables for Optimization. Choose the MySQL Database Service with HeatWave during setup. Feb 27, 2013 · The ANALYZE TABLE runs perfect but after it the rest of the threads that are running a query against that table need to wait. From the documentation: OPTIMIZE TABLE is mapped to ALTER TABLE, which rebuilds the table to update index statistics and free unused space in the clustered index. OPTIMIZE TABLE does a table repair and a key analysis, and also sorts 10. The guidelines cover SQL operations that read and Nov 21, 2023 · Table does not support optimize, doing recreate + analyze instead Code language: SQL (Structured Query Language) (sql) It means that the OPTIMIZE TABLE does not optimize the InnoDB tables in the same way it optimizes the MyISAM tables. These software constructs result in CPU and I/O operations at the hardware level, which you must minimize and make as efficient as possible. InnoDB is the storage engine that MySQL customers typically use in production databases where reliability and concurrency are important. Apr 20, 2024 · Tip 8: Query the Cache. You can optimize a table in the same way by using the OPTIMIZE TABLE SQL statement. A thing not mentioned so far but making a huge difference is adequate indexing of the views' source tables. For MyISAM tables, ANALYZE TABLE for key distribution analysis is equivalent to using myisamchk --analyze . SELECT column_list Below is our SELECT * sample: Jul 9, 2024 · The MySQL EXPLAIN ANALYZE command provides information about the query execution plan, including specifics about the optimizer’s decisions, access methods, and estimated costs. I am addressing the implied question -- "Should I OPTIMIZE?". MySQL 5. Premature optimization is the root of all evil. 13. The second statement updates the histograms for c1 and c3, leaving the c2 histogram unaffected. 7. We would like to show you a description here but the site won’t allow us. Optimize and repair all tables in all MySQL databases. This section discusses optimization techniques for the database server, primarily dealing with system configuration rather than tuning SQL statements. Sometimes, the primary index is not useful or problematic. Caching can improve performance by allowing data to be stored for faster access, and the MySQL query cache is no exception. SELECT empl_name, empl_salary from EMPLOYEE; END. 5 Optimizing for InnoDB Tables. 1. 1 OPTIMIZE TABLE syntax I’ve been researching how to optimize only fragmented tables in MySQL and reviewed this post on optimizing tables. Jun 14, 2022 · In this post, we showcased how to use EXPLAIN and EXPLAIN ANALYZE to analyze Athena SQL queries for data sources on AWS S3 and Athena federated SQL query for data source like DynamoDB and Amazon RDS for MySQL. For MyISAM tables, this statement is equivalent to using myisamchk --analyze. 4 OPTIMIZE TABLE Statement. It will plan the query, instrument it and execute it while counting rows and measuring time spent at various points in the execution plan. Dec 7, 2023 · 5 Examples of MySQL Analyze Query Execution Plan (with Tips) The lessons about EXPLAIN earlier provide the foundation for MySQL analyze query execution plans. Dec 16, 2011 · "Optimize" is usually useless; don't bother. mysqlcheck must be used when the mysqld server is running, which means that you do not have to stop the server to perform table maintenance. 5. There are multiple ways to show tables and analyze them for optimization. It provides valuable information on how the MySQL engine accesses the table data, and can help you identify issues with slow query performance. " MySQL Workbench: Performance. cnf file. As you work on database performance, you start by Tables consume some space that isn't actively in use, but Amazon RDS allocates that space to the tables anyway. 19. Only one table name is permitted with this syntax. #2 and #3: Check up on MySQL storage engines and schema design. Aug 24, 2022 · Queries contribute to the performance of a MySQL database. Table maintenance of partitioned tables can be accomplished using the statements CHECK TABLE , OPTIMIZE TABLE , ANALYZE TABLE, and REPAIR TABLE, which are supported for Mar 20, 2024 · Here are the benefits of MySQL performance tuning: Cost Optimization: Identifying the performance-driving factor allows you to avoid over-provisioning and reduce costs by right-sizing servers. TABLES, will trigger the same refresh of table statistics that ANALYZE TABLE does. Simply using a partition_options clause with ALTER TABLE on a partitioned table repartitions the Analyzing a table in MySQL involves examining and processing its structure to optimize its performance. Table Dec 24, 2020 · 2. Then do the same thing the day after, if the Apr 4, 2012 · The ‘EXPLAIN’ statement in MySQL is a powerful tool that provides information about how MySQL executes queries. Jun 30, 2022 · Fixing Slow Queries. TABLEAS SELECT , INSERT. 0. If you are joining these small tables you probably would like to analyze them. If you’re running Innodb Plugin on Percona Server with XtraDB you get the benefit of a great new feature – ability to build indexes by sort instead of via insertion. 6. To know it, run the below command. 7 Improving Replication Performance. Depending on your job role (developer, DBA, or a combination of both), you might optimize at the level of individual SQL statements, entire applications It allows you to analyze and improve slow-running queries. Database access optimization. # Command to create MySQL DB System with HeatWave. You should definitely run it periodically just like vacuum in Dec 29, 2022 · In this article, we’ll walk through five ways to quickly improve your MySQL database performance. 1 Mar 9, 2019 · Doing optimize table on an InnoDB table is usually not necessary to do frequently, but only after you do a lot of insert/update/delete against the table in a way that could result in fragmentation. Any extra information relevant to the query. May 25, 2021 · Bill is addressing your stated question -- "When should I OPTIMIZE?". x. Sep 20, 2022 · 2. However, for a "big delete" there may be a way to avoid the fragmentation. The first step is to identify whether you have fragmentation on your MySQL database. This doesn't require building a copy of the table. Always place it at the beginning of the query. TABLE can be used with partitioned tables for repartitioning, to add, drop, discard, import, merge, and split partitions, and to perform partitioning maintenance. MySQL does optimize queries before running them. 10. The focus is very much on the InnoDB storage engine, but the documentation links provide more information, including how the functionality related to the MyISAM storage engine. OPTIMIZE TABLE uses online DDL for regular and partitioned InnoDB tables, which reduces downtime for concurrent DML operations. You can use OPTIMIZE. It basically performs a query against the information_schema database for any table with data_free > 0 and builds a SQL statement to OPTIMIZE only those tables. The guidelines cover SQL operations that read and Jul 1, 2024 · SHOW TABLE STATUS LIKE “<table_name>” \G. Let’s get started! MySQL and your applications. 18 there is a new feature called Explain Analyze when for many years we mostly had only the traditional Explain. Hence, connect to the MySQL DB instance, and run the below query. The precompilation makes execution faster, as the procedure once compiled remains in the cache unless it is altered. ANALYZE TABLE, by itself (without the "optimize" part) is fast and usually useless. Just because this quote can never be told to often. This statement works with MyISAM, Aria and InnoDB tables. The third statement removes the histogram for c2 , leaving those for c1 and c3 unaffected. EXPLAIN ANALYZE is a useful tool for query performance study since it performs the query and offers runtime information, unlike EXPLAIN, which only presents the Mar 29, 2023 · If you multiply the rows column by this percentage, you will see the number of rows MySQL estimates it will join with the previous tables in the query plan. If innodb_file_per_table is turned on (it's turned on by default), then you can reclaim that space using OPTIMIZE TABLE. May 6, 2017 · I have a question about optimize table of mysql,I have read many documents about this function,all of the document says:it can defragment an InnoDB table and reorganizes the physical storage of table data and associated index data, to reduce storage space,but no one can tell me the principle of optimize table and slove my questions,I have May 23, 2017 · OPTIMIZE TABLE works fine on InnoDB tables. The exact changes made to each table depend on the storage engine used by that table. We will use them here in our examples. As a dry run I ran the same command (optimize table) on a smaller table in the same DB and mysql insists on a recreate+analyze instead. Note that I'm using barracuda format and file-per-table. To recap, by using EXPLAIN, you get the list of things expected to happen. MySQL 8. 8. During the analysis, InnoDB will allow reads/writes, and MyISAM/Aria reads/inserts. You can use this as an example to optimize queries which would also result in cost savings. This is intended to be a temporary setting, and should be reset to 0 once the fulltext index has been re-organized. It is primarily used to optimize queries for better performance. 7. ` This allows MySQL to quickly locate orders for a specific user and sort them by date. Table maintenance of partitioned tables can be accomplished using the statements CHECK TABLE , OPTIMIZE TABLE , ANALYZE TABLE, and REPAIR TABLE, which are supported for partitioned tables. I agree that when you do a big DELETE, OPTIMIZE may be desirable. . I ran this query and it identified 148 tables for optimization. The information in this section is appropriate for DBAs who want to ensure performance and scalability across the servers they manage; for developers Jun 2, 2010 · It's used for reclaiming space and recreating indexes. MySQL EXPLAIN vs. The EXPLAIN statement provides information about how MySQL executes statements: EXPLAIN works with SELECT , DELETE , INSERT , REPLACE, and UPDATE statements. I'd say run that rarely if at all. 2. That is, viewing the table status, or querying INFORMATION_SCHEMA. TABLE tbl_name [, tbl_name] OPTIMIZE TABLE reorganizes the physical storage of table data and associated index data, to reduce storage space and improve I/O efficiency when accessing the table. Since fulltext re-organization can take a long time MySQL 8. #4. 0. This section explains how to optimize database operations for InnoDB tables. BEGIN. In order to use it to update fulltext index statistics, the innodb_optimize_fulltext_only system variable must be set to 1. Analyze + Optimize on InnoDB Tables. Optimization involves configuring, tuning, and measuring performance, at several levels. Note that 'optimize table' for innodb just maps to an 'ALTER TABLE foo engine = innodb' statement. Enter the name for your schema and click the “Apply” button. TABLE to reclaim the unused space and to defragment the data file. Design your tables to minimize their space on the disk. The tuning guidelines in this section help to speed up all kinds of MySQL applications. Therefore the table will be locked until all queries that are using that table finish. When you prefix Oct 28, 2019 · In MySQL 8. To optimize a table, you can use the OPTIMIZE TABLE command. And, yes, it takes a long time because it copies the table(s) over, plus rebuilding the INDEXes from scratch. SHOW TABLE STATUS LIKE "password_history" \G. By default, the MySQL client installation includes the mysqlcheck. The Performance Dashboard and reports allow DBAs to easily view overall server performance, and various reports provide views of IO hotspots, SQL statements, Network, Data Engine, and more. Add an Index: Ensure there are indexes on ` user_id ` and ` order_date . You can safely ignore that message. 6 and I am trying to optimize a large table without mysql recreating it. TABLE is completed in place. The above example is a simple procedure named spEmployee. For example: OPTIMIZETABLE your_table_name; Simply replace your_table_name with the actual name of the table you want to optimize. 9. In fact, what runs has no obvious relationship to the SQL statement itself -- it is a directed acyclic graph. Oct 17, 2019 · EXPLAIN ANALYZE is a profiling tool for your queries that will show you where MySQL spends time on your query and why. 1 ALTER TABLE Partition Operations. You can maximize MySQL cache optimization by caching the content. The EXPLAIN keyword is an extremely powerful tool to understand and optimize MySQL queries. I know there are different formats, but those based on the same information just show it in a different format with some extra details. ) Jul 23, 2019 · Analyze table update statistics that is used for optimizer while choosing indexes. ¶. ANALYZE TABLE is much less impact for InnoDB. mysqlcheck just runs a bunch of 'optimize table' SQL statements for you, so functionally they do the same thing. Is there a way to turn off the creation of a temp table during ALTER TABLE? ANALYZE TABLE with the UPDATE HISTOGRAM clause generates histogram statistics for the named table columns and stores them in the data dictionary. Improving database performance in general. Though EXPLAIN and EXPLAIN ANALYZE are sometimes used interchangeably, they have a key difference. After extensive changes to a table, this statement may also improve performance of statements that use the table, sometimes significantly. 1 Optimization Overview. 4. It is actually going to run the query 10. The precise effects of this variable are described later in this section. For example, poorly written queries can prevent the optimizer from performing well. Is there a way (built-in command or common stored procedure) to run this optimization for every ta Oct 5, 2010 · 10. The exact changes made to each table depend on the storage engine used by 10. Jul 24, 2023 · The EXPLAIN output shows how MySQL plans to execute the query, including the chosen indexes and the order of table access. What is EXPLAIN ANALYZE. Arrows showing steps in naming your schema in MySQL Workbench. Thus everything that makes the rebuild easier for the DB increases performance of the view. So if you're inserting the same type of stuff at the same rate over time - no need to run analyze often - do it maybe once a month. InnoDB is the default storage engine in MySQL. To optimize several tables simultaneously, list them separated by commas: OPTIMIZETABLE table_name1, table_name2, table_name3; 8. But Explain Analyze is a different concept. This article provides an in-depth guide to drastically improving MySQL performance to educate database engineers on query optimization. . The server maintains histogram statistics about column values in the column_statistics data dictionary table (see Section 10 The EXPLAIN statement provides information about how MySQL executes statements. We will look at the stats for the password_history table. 4, the default output format used by EXPLAIN (that is, when it has no FORMAT option) is determined by the value of the explain_format system variable. EXPLAIN can be used with SELECT, DELETE, INSERT, REPLACE, and UPDATE queries. If your MySQL database runs slowly, you can do a few things to speed it up — like optimizing your tables. Partitioning-related clauses for ALTER. Jul 26, 2019 at 0:02. Table maintenance of partitioned tables can be accomplished using the statements CHECK TABLE , OPTIMIZE TABLE , ANALYZE TABLE, and REPAIR TABLE, which are supported for A number of table and partition maintenance tasks can be carried out using SQL statements intended for such purposes on partitioned tables in MySQL 5. Oct 19, 2016 · The following command will repair all tables in both blog and blog2 databases: $ mysqlcheck -r --databases blog blog2. 4. From MySQL 8. Limit the amount of data retrieved 26. Connect to your MySQL database, and execute the following query, which will display how much unused space are available in every table. MySQL provides optimizer control through system variables that affect how query plans are evaluated, switchable optimizations, optimizer and index hints, and the optimizer cost model. If we run the explain statement one more time, we will get the below results: Jul 2, 2015 · At the MySQL documentation I read this: To coalesce fragmented rows and eliminate wasted space that results from deleting or updating rows, run myisamchk in recovery mode: shell> myisamchk -r tbl_name. 02 sec) Records: 0 Duplicates: 0 Warnings: 0. free data and other information about the table. MySQL also supports setting the histogram of a single column to a user-defined JSON value. – fifonik. Oct 13, 2022 · MySQL Enterprise Monitor is a monitoring tool that keeps an eye on MySQL real-time instances and hosts, notifies users of potential problems, and tells them how to fix them. A number of table and partition maintenance tasks can be carried out on partitioned tables using SQL statements intended for such purposes. Feb 20, 2024 · Using EXPLAIN ANALYZE. Jun 13, 2020 · Analyze Table (分析表) MySQL 的Optimizer(优化元件)在优化SQL语句时,首先需要收集一些相关信息,其中就包括表的cardinality(散列程度),它 表示某个索引对应的列包含多少个不同的值——如果cardinality大大少于数据的实际散列程度,那么索引就基本失效了。. It performs a similar function in MySQL as PostgreSQL in that, depending on the storage engine used, it reclaims unused space, reorganizes indexes and tables, and defragments data files. Database performance depends on several factors at the database level, such as tables, queries, and configuration settings. il tg gt uw jd ft qx rq oa qo