a. This statement requires the SELECT privilege for the table. Query with Join of tables is taking long time to execute. EXPLAIN SELECT * FROM (SELECT * FROM t1) AS derived_t1; The optimizer avoids materializing the derived table by delaying it until the result is needed during SELECT execution. ALTER DATABASE CURRENT SET COMPATIBILITY_LEVEL = 140; GO. rate, c. This statement is not supported for views. If you want that your queries will be faster, optimize your table. Since it's the Django internals, the query cannot be changed. The table is MyISAM table. id4. I have a 1,000,000 x 50 Pandas DataFrame that I am currently writing to a SQL table using: df. date, b. 7. The rows are essentially write once read many. 2. Apr 17, 2021 · The following recommendations may help optimize your data loading operations: Remove existing indexes - Inserting data to a MySQL table will slow down once you add more and more indexes. Connect to your MySQL database, and execute the following query, which will display how much unused space are available in every table. Jan 30, 2014 · But every time MariaDB need to write data (for example insert a new row, create a database, delete a row) it takes ages. Optmize doesn't take so much like delete. MYD and #sql-9999. The best way to improve the performance of SELECT operations is to create indexes on one or more of the columns that are tested in the query. The "IN" - clause is known in Oracle to be pretty slow. 4 OPTIMIZE TABLE Statement. OPTIMIZE TABLE copies the data to a new tablespace, and rebuilds indexes. Big Changes need to be done: Alter table tablename engine = 'INNODB'. Table with variable-length rows: Tables with variable-length data such as VARCHAR, TEXT, and BLOB may become fragmented over time. Even after the query runs the first time and the data’s cached in RAM, this still ain’t fast: Pages read: 694,389. I could add extra processors and servers to the machine if that helps but at this Jan 7, 2020 · If you are deleting the whole table, use TRUNCATE or DROP / CREATE. Swap the current table with the new table in an atomic operation with a one time lock, which will be done in perceivably Apr 7, 2017 · 1. It is possible that the rows you deleted had very little VARCHAR, TEXT, or BLOB data or even NULL values. The group by query I am running is: SELECT word,group_concat(p_id) FROM Words group by word; To optimize this problem, I sent all the data in the table into a text file using the following query. SELECT * FROM <CTE name> Just before the main query that pulls the CTEs together and highlighting and running the script down to that point. Solution: Re-declare parameters or optimize the stored proc for unknown parameter values. DELETE n1. sql. 3 Optimization and Indexes. 5 innodb with file_per_table. id1 = b. The real solution is, define a query that can fetch all useful data (no junk) from your data. So when I change the query to this it takes 7 minutes to execute: select a. id = b. CTEs are similar to derived tables, for which the materialized_from_subquery node follows the reference. I'm having issues with a database that is getting quite slow. The table only had about 300. The Votes table is only ~5. 5k 38 278 396. the mysql query cache was turned off to demonstrate. 5 default innodb_max_dirty_pages_pct is 75. Here is what I suggest: About 1 hour before performing the backup run this SQL command. 5 million in around 3 hours. Jun 30, 2022 · Fixing Slow Queries. SHOW TABLE STATUS LIKE "password_history" \G. Please help to check the problem. ON n1. When I'm trying to execute query that selects points that are spatially near to the query points, total execution time takes too long. rate>0 Why would this make the query time go up from 1 sec to 7 mins? Feb 15, 2024 · Another way is to drop the index, optimize the tables, and add the indexes back. MYD if it's MyISAM) in your filesystem and see how long that takes. 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. aid c inner join b. MySQL also allows you to optimize multiple tables in a single command as follows: mysql> OPTIMIZE TABLE EMPLOYEE, DEPARTMENT, BENEFITS. 4. It disappeared from the processlist and my replicant began the long process of Apr 10, 2017 · DROP TABLE old; If you make it this far, ADD back the indexes you should have. ibd is the same size, then it is already defragmented as much as possible. INNER JOIN c ON b. Add any conditions you want where I put , to filter the tables you want to list. uID,e. Feb 9, 2014 · 3. The index entries act like pointers to the table rows, allowing the query to quickly determine which rows match a condition in the WHERE clause, and retrieve the other Feb 16, 2022 · What I feel to suggest is to enable log on slow query in my. Step 3: Use the OPTIMIZE function that is provided by MySQL and use it on the table that we need to optimize. The higher is this value, the longer the query runs. You can use this statement to verify that the contents are the same before and after a backup, rollback, or other operation that is intended to put the data back to a known state. to_sql('my_table', con, index=False) It takes an incredibly long time. (Did you check?) And it takes a long time. This is easy to do in SSMS by adding a. Potential problem: If the table is Engine=InnoDB and was created with innodb_file_per_table=OFF, then this is not sufficient to free up any disk space. 11, “Previous NDB Cluster Issues Resolved in NDB Cluster 8. By using the OPTIMIZE TABLE statement, you can reduce the storage overhead. (Or just drop the old table, rename the new, and re-apply constraints / permissions etc. I'm running a very simple MySQL query via workbench in order to count the number of entries in a table: SELECT COUNT(*) FROM database. Suppress the row count: One of the most simple things you can do to increase the performance of a stored procedure is SET The performance of OPTIMIZE on NDB Cluster tables can be tuned using --ndb-optimization-delay, which controls the length of time to wait between processing batches of rows by OPTIMIZE TABLE. Add index if applicable. 000 records but it also took way too long. Oct 20, 2014 · A join involving half a million rows -- as your query plan shows -- is bound to take some time. create table interm1 as select device_uuid,name from Table name a query like this is taking around 20-30 minutes. Jan 12, 2015 at 12:59. Jun 2, 2010 · It's used for reclaiming space and recreating indexes. This is the time the ALTER TABLE will at least take. Jan 26, 2018 · In my application I have to join tables with millions of rows. B. An update statement is optimized like a SELECT query with the additional overhead of a write. The table in question stores logs. 12. It reorganizes the storage data in a way that increases the Input Output efficiency and reduces the storage space. mysqldump -u root -p --opt [database name] > [database name]. Jul 12, 2012 · But I need a resultset to get the results that has rate greater than 0. mysql 5. free data and other information about the table. This will reduce the number of indices you need. sID. But doesn't it lock the table and block queries while you optimize? Yes, sort of. This process can help improve performance by reorganizing how data is stored and accessed. 63 to 0. Potentially valid is to copy over the useful rows, a la Rolando's #4. We must be connected to our database using the following command. OPTIMIZE TABLE works for InnoDB , MyISAM, and ARCHIVE tables. It had around 17 million records. Jun 7, 2022 · The first method, as shown below, is to use the Optimize table command. Another hint for deleting many many rows Consider the following EXPLAIN statement, for a SELECT query that contains a derived table: . This technique will shave shrink the disk footprint upwards of 3:1. SELECT e. SELECT query taking too long after MySQL upgrade. Feb 14, 2020 · Correct. tables where table_type='BASE TABLE' AND " > myscript. So my question is, is there a faster way to do this? Further Info/Findings. 441 sec. 3GB, so I’m able to cache the whole thing in my SQL Server. In this example, we optimize the EMPLOYEE table. The result of the aforementioned query will depict the status of the optimization for every optimized table. If I try the method in: Bulk Insert A Pandas DataFrame Using First: Optimize your table structure. I had the problem where I wanted to speed up my query by adding an index. This will analyze the table and make changes to improve performance. 2 Optimizing UPDATE Statements. This fragmentation can lead to wasted disk space and slower query performance, undermining the efficacy of your applications. sql Which took about 3 hours and created a file 45GB in size. I did some research and found out there is no proper way to check the status of an optimize table. For more information, see Section 25. Votes; GO. The reorganized tables require less disk I/O to perform full table scans. 25 minutes and counting. If your MySQL database runs slowly, you can do a few things to speed it up — like optimizing your tables. name = 'xxx' and b. We will look at the stats for the password_history table. 2. Keep the tables and the JOIN s, keep the WHERE conditions, drop the SET clause, add COUNT() of relevant field (s) in SELECT. Oct 8, 2012 · The ALTER TABLE involves copying over all the data from the table and recreating the indexes. 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. ) If you deleted half of the rows, you should optmize your table. This will help you lot and possibly there should be one primary key in the table but you have added three column as primary key. Another way to get fast updates is to delay updates I have a Django web application that stores data in a MySQL InnoDB database. Aug 9, 2022 · 0. To optimize a table, you can use the OPTIMIZE TABLE command. user_id = n2. If a query is flagged for compiling, the compiling and the updating of statistics occurs the next time that the query is run. I don't work with mysql so maybe it is just some unique way to join, but usually you join like: FROM. 0” . id = c. Jul 7, 2017 · But the 'src_woz_waardeklasse_2011' table is nearly 7 million records and the 'waardeklasee_average' table is 46 records. Apr 27, 2012 · Optimize Table Taking Forever. After extensive changes to a table, this statement may also improve performance of statements that use the table, sometimes significantly. As a first measurement try copying the data file (item_catalog_map. May 4, 2023 · optimize query taking too long to run. SET GLOBAL innodb_max_dirty_pages_pct = 0; In MySQL 5. Be aware that changing the engine type for an existing application might have consequences as InnoDB has better data integrity and some functions your application might be depending on. FROM ids AS n1. Compiling typically takes from one second to four seconds. #1: You probably don't want an Outer Join, so replace it with an Inner Join (MySQL's optimizer is known to be weak determining if an Outer Join can be rewritten as an Inner Join). The count(*) query is quicker because it doesn't need to read the tabla_maestra table itself, but it still needs to scan all the rows of index cruce_empresa_apellido1. Therefore, if you're loading data to a new table, it's best to load it to a table without any indexes, and only then create the indexes, once the data was I had a similar problem with several lookup tables joining to a large table with all id fields indexed. log. 1. In MySQL 5. In the end I restarted the server then started up mysql again, and started the slave, but immediately killed the optimize table, and this time it worked. Hint: Temp table are MyISAM tables that do not have a . This takes a long time for a large table. May 25, 2021 · So should you optimize such tables? Maybe! It wouldn't be a bad thing to do it, say once a month. Oct 3, 2010 · 10. Write queries that do not use the term distinct. An ORDER BY with and without LIMIT may return rows in different orders, as discussed in Section Oct 12, 2008 · 3. But I'll update this in-case anyone with the same problem ever comes across it. I've found out that the fastest way (copy of required records to new table): Create Temporary Table that holds just ids. There are approximately 3 million entries in the table but it is taking over 10 minutes to count the number of entries. Optimize the query based on these results; if for example you see table scans then an index may assist. Mar 6, 2023 · Some popular query optimization tools include Microsoft SQL Server Query Optimizer, Oracle SQL Developer, and MySQL Query Optimizer. Then it does the GROUP BY do deflate that back to one row per team. FROM ids. Jun 13, 2018 · ALTER TABLE ids ADD INDEX (user_id, id); This makes it efficient to find all the rows with the same user ID and higher IDs. We backed up the data with . And the query is quite simple, which returns only ~17000 rows. #2: Remove the function on d. I want to check to see how many rows in staging are not present in users. My update query on a similar size dataset went from 100 ms to 0. There is a table with around 300 million rows, it's gotten to 1. That's why I use pt-online-schema-change to run a no-op change (use the --alter=force option), so it can be done any time, without blocking clients. id2. type, a. Jan 12, 2015 · Jan 12, 2015 at 12:56. I had thought about divide the two queries, but I can't because . If you're worried about duplicates, use UNION ALL to select everything into a temporary table or subquery, and then GROUP BY every column you are returning to Apr 26, 2018 · A notification_followers table gets a single notification when a leader adds a post with an entry leader_id 1 and notifiable_id 0 (id 1,2 in table). Every week I insert about 150,000 rows into this table. 8. The tables are all InnoDB and there are no foreign keys defined. See execution plan below: Additional detail from the table scan: SQL Server Execution Times: CPU time = 3945 ms, elapsed time = 148524 ms. Nov 2, 2023 · Over time, tables in your MySQL database can become fragmented due to frequent insert, update, and delete operations. Before running the UPDATE you can turn it into a SELECT to find out how many rows will it modify. I deleted just over half of them because disk space was starting to become an issue. 3. I would like to know what is the frequency with which I need to run "analyze" and "optimize" on this table (as it would probably take a long time and block in the meantime)? I do not do any deletes or update statements, but just insert new rows every week. value from a inner join b on a. Right now, I can't setup a basic WordPress website, because the creation of the database is so long that my browser times out. I'd say run that rarely if at all. Output list of tables formatted into OPTIMIZE TABLE statements: from information_schema. This way is only applicable if the table can work without indexes for a short time. foo. Jul 12, 2024 · Use the slow query log to identify and optimize queries that take a long time to execute. JOIN (SELECT user_id, MIN(id) AS minid. Sep 14, 2017 · ParentKey varchar(32) NOT NULL, PRIMARY KEY (SourceId, GeneratedKey), KEY IX_RowModifiedDateUtc (RowModifiedDateUtc), KEY IX_ParentKey (ParentKey), KEY IX_OperationId (OperationId(36)) Here is the update query: This query updates ~80k rows and takes around 60 seconds to complete, and the more rows updated the longer it takes which results in Oct 18, 2017 · 0. ibd files be a viable option. Monitor query performance By default, an OPTIMIZE TABLE will defragment a table. 7 I believe) and so I think that at startup it is scanning every . Is there a way to optimize it? I am sure it's taking a long time as I am trying to compare values between a large table and a small table. 484 sec / 27. Feb 11, 2019 · Copy the table data into the new table. 1 and back, default innodb_max_dirty_pages_pct is 90. But, as already mentioned, InnoDB cleans up the free space somewhat. The query looks like: Apr 24, 2017 · 16. Use less disk space. 4. Since fulltext re-organization can take a long time Aug 19, 2016 · UNION tries to sort out all the distinct queries from each table one it has brought them all back. To monitor the effect of the joins on query time execution, I ran my query several times (limiting to first 100 rows), adding a Join to an additional table each time. 1 Optimizing Storage Layout for InnoDB Tables. More precisely Duration / Fetch = 0. This statement requires SELECT and INSERT privileges for the table. If you know the person's gender most of the time, but not always, you can make this column nullable and set it to NULL when information is not available. So, it seems that the whole thing would take 600 hours (that's 24 days) and is impractical. I will try to drop all indexes and see Nov 20, 2022 · If you ran OPTIMIZE TABLE table1; multiple times and the the file table1. 65. 5 on solaris 10. MySQL SET GLOBAL slow_query_log = 1; SET GLOBAL long_query_time = 2; -- Log queries that take longer than The performance of OPTIMIZE on NDB Cluster tables can be tuned using --ndb-optimization-delay, which controls the length of time to wait between processing batches of rows by OPTIMIZE TABLE. startDate. That won't eliminate the OPTIMIZE issue, but it will. long_query_time = 2. Aug 26, 2017 · After I ran “optimize table” on every table in the mysql docker, the query ran 22 times faster than before and 4-5 times faster compared to the non-docker MySQL installation. Then after have found the incriminate query, we can explore what make it slow using EXPLAIN: EXPLAIN SELECT * FROM (SELECT * FROM test3 WHERE idx = 5116 ORDER BY id DESC LIMIT 2) sub ORDER BY I have a large (40GB) table I would like to partition. A query that gets data for only one of the million users and needs 17 seconds is doing something wrong: reading from the (rated_user_id, rater_user_id) index and then reading from the table the (hundreds to thousands) values for the rating column, as rating is not in any index. Nov 21, 2023 · The OPTIMIZE TABLE statement can help rearrange the storage structure and eliminate wasted space. If you are deleting most of the table, use SELECT INTO to put the data you want to keep into another table, then TRUNCATE, then move the small portion back. Be faster (due to having less data to shovel around). Are there pros and cons I should take Apr 28, 2015 · OPTIMIZE TABLE rebuilds (and ANALYZEs) the table but takes forever on this sized table. May 31, 2024 · Optimize MySQL Tables Statement: Optimizing Multiple MySQL Tables at once. Here's another quote from "MySQL administrators guide" OPTIMIZE TABLE does a table repair and a key analysis, and also sorts the index tree so that key lookups are Dec 22, 2016 · Test each CTE on its own from top to bottom to see if/where execution times or row counts explode. – axiac. Run that result as an SQL script: (I omitted options for --hostname 10. Run an ANALYZE on the new table. frm file with the name #sql-9999. Example Code: If you are using this option to check tables, it ensures that they are 100% consistent but takes a long time. answered Jul 6, 2011 at 15:25. To optimize the table will help to reduce the size (index will be recalculated etc. Nov 12, 2015 · That is, that table is much bigger than any of the original tables. SELECT COUNT(*) FROM dbo. A query is flagged for compiling when you save any changes to the query (or its underlying tables) and when the database is compacted. MYI . 1. Dec 9, 2010 · I have a innodb table 650 GB in size and data shall be 100 GB. However, after a complete drop database and fresh import of all tables, the performance of the query was just as fast as after the optimization of the tables. 16 ORDER BY Optimization. If you don't delete more than 90% of the table, and you have only 69GB of free space, the process will eventually fail. Even drop database X statement takes more than 30 seconds, for an almost empty DB. 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). The first step is to identify whether you have fragmentation on your MySQL database. If you have access to SQL Server, highlight your complete query in SQL server, and click + L. 5. Takes several minutes. where [whatever where conditions you want] group by foo; edited Oct 2, 2015 at 17:32. Another way to get fast updates is to delay updates Jun 20, 2023 · The join order is somewhat weird. I have another table called staging with around 75,000 records in it. I have the following query, which I have tested on CHECKSUM TABLE reports a checksum for the contents of a table. Running OPTIMIZE TABLE after deleting such rows won't really make a significant dent in space. Indexes that are not changed do not get updated. One thing you might try is adding an composite index to see if it speeds up the select part of the query: ALTER TABLE `transactions` ADD INDEX `user_confirmed` (`user_id`, `confirmed`); Also, as @wajeeh pointed out in a comment, the LIMIT clause is unnecessary here since you're already calling an aggregate function. 15. When I checked the mysql server processes, it turned out that the query I was trying to optimize was still running in the background. The MySQL OPTIMIZE table helps you to optimize the table storage space. So the query is taking a really long time. Apr 28, 2012 · Re: Optimize Table Taking Forever. minid. user_id AND n1. If you are using this option to repair tables, it runs an extended repair that may not only take a long time to execute, but may produce a lot of garbage rows also! --default-auth=plugin Jul 30, 2015 · 235. I then ran optimize table. After joining 12 tables, there was no significant change in query execution Nov 10, 2020 · In my configuration, I observed that innodb_file_per_table = ON (which is the default for MySQL 5. There is a particular page that is accessed a lot on the django admin, and the query is taking a long time (~20 seconds). TABLE to reclaim the unused space and to defragment the data file. May 25, 2017 · I had a use case of deleting 1M+ rows in the 25M+ rows Table in the MySQL. INNER JOIN b ON a. Optimize Tables in MySQL. i found it in a legacy system after 5 years that tables was grown. The exact changes made to each table depend on the storage engine used by that table. Nov 10, 2009 · MySQL JOIN Query taking far too long to complete. I've seen various explanations about how to speed up this process online, but none of them seem to work for MSSQL. SELECT p_id,word FROM Words INTO OUTFILE "/tmp/word_map. Identify Tables for Optimization. I use 'optimize table ' to maintein a table very Monday and Friday, usaually it needs 1 hour normally , but sometime ,the 'optimize table' operation take serval hours or longer, today the 'optimize table ' runs for near 10 hours and not finish . For example: AND TABLE_SCHEMA='myschema'. It's tough to optimize this table since rebuilding the entire file takes a very long time. Usually the combination gives COUNTs and SUMs that are bigger than expected. 1 ms. id > n2. 4 times! After I killed those queries, indexing was done in a jiffy. N. from my_table. Since you are using INNER JOIN this way you first filter out a with b joins and only then use the remaining join to filter out thus saving a lot Apr 23, 2013 · I am running a group by query and it is taking 90+ minutes for running that query. The speed of the write depends on the amount of data being updated and the number of indexes that are updated. I use 'optimize table ' to maintein a table very Monday and Friday, usaually it runs 1 hour normally , but sometime ,the 'optimize table' operation take serval hours or longer, today the 'optimize table ' runs for near 10 hours . Oct 21, 2011 · 5. One thing to note is that in general, every I use 'optimize table ' to maintein a table very Monday and Friday, usaually it runs 1 hour normally , but sometime ,the 'optimize table' operation take serval hours or longer, today the 'optimize table ' runs for near 10 hours . ibd file. 10. So, the trick is to use subqueries to avoid any single query with both JOIN and GROUP BY Jan 31, 2017 · What helped for me was changing the engine from 'innodb' to 'myisam'. May 13, 2014 · This is useful, though the plan is cached, and will get out of date, causing the stored proc to run on an inefficient execution plan. There are 3 tables, A, B, and C. try using "EXISTS": SELECT orderID FROM tasks WHERE orderID NOT EXISTS. cnf: slow_query_log = 1. analyze should be redone whenever the overall distribution of the indexed data changes significantly. optimize table was taking huge time . To indicate one-time materialization, optimizer trace output contains an occurrence of creating_tmp_table plus one or more occurrences of reusing_tmp_table. Jun 20, 2009 · It also has a very positive affect on query performance, reducing the select query response time from 0. optimize table doc. But only if you are jettisoning "most" of the table. This will show the query execution plan. The CPU,disk IO and Memory status are OK. This query is too slow, it takes between 40s (15000 results) - 3 minutes (65000 results) to be executed. If you know for sure there are no duplicates then you can use UNION ALL instead. I had to cancell in between as speed suggested it will take more than 1 day. (SELECT DISTINCT orderID FROM tasks WHERE. Staging only has one column, msisdn. Would changing innodb_file_per_table = OFF and then altering each table to get rid of the . Apr 11, 2013 · Thoughts on the issue, thrown in random order: The obvious index for this query is: (rated_user_id, rating). Dec 28, 2012 · Queries for reporting always spent a lot time. Apr 5, 2012 · Running a simple query to return the 100 most recently updated records: select top 100 * from ER101_ACCT_ORDER_DTL order by er101_upd_date_iso desc. It copied over to its new home overnight and, next morning, I used MySQL Workbench to launch a Jul 6, 2011 · Oftentimes, you can make such queries run faster by working around the distinct by using a group by instead: select my_table. Apr 25, 2016 · This tutorial explains how to optimize MySQL to defrag tables and reclaim unused space. id3 = c. The query cannot go right to OFFSET because, first, the records can be of different length, and, second, there can be gaps from deleted Basically this table contains points of interest of an image with respective descriptors. But before doing so, I would (of course) like to know if there is anything that can happen to the data in the tables, or if this operation is entirely harmless. I have a table called users with roughly 250,000 records in it. MySQL OPTIMIZE TABLE Statement. I know that optimize table is supposed to take quite a long time, but it has now been around 10 hours and I'm still waiting for it to finish. In fact, the internal query optimizer in Oracle cannot handle statements with "IN" pretty good. Sep 5, 2010 · I have an index on f2. If most of the time the person's gender is not known, then it may better to have a separate table gender that links to person 1:1 and has rows only for those people who have a known gender. Rather than having columns as bools for student, teacher and arranger you could have a singular column named something like " participant_type " and have 1-3 for student, teacher and arranger. Try Optimize the table using Optimize table tablename and check the status. First, we should analyze the tables that we want to optimize. ID,e. mysql> use bobcares; mysql> OPTIMIZE TABLE EMPLOYEE; There are a few things to keep in mind when optimising a table: InnoDB, MyISAM, and ARCHIVE tables can all benefit from table optimization. May 14, 2009 · i had WHERE date_index>NOW() - INTERVAL 24 HOURS and an ORDER BY id in query, MySql preferred id as index and it didn't use date_index that caused long query time for big tables. txt"; Apr 30, 2012 · I tried killing it again, which didn't work, so I then tried to shut down mysql, but that also just hung. Defragmenting an InnoDB table doesn't improve performance much, since internally the pages are typically stored out of order regardless. table. 39 seconds. Dec 26, 2019 · 3. Well after 47 hours of waiting, and no advice from here, the situation stayed the same so I had to sort it out. CREATE TABLE id_temp_table ( temp_id int); Jul 1, 2024 · SHOW TABLE STATUS LIKE “<table_name>” \G. This is intended to be a temporary setting, and should be reset to 0 once the fulltext index has been re-organized. I have a query like this: The table "files" has 10 million rows, and the table "value_text" has 40 million rows. It will also help to join with a subquery. GROUP BY user_id) AS n2. Once your data reaches a stable size, or a growing table has increased by tens or some hundreds of megabytes, consider using the OPTIMIZE TABLE statement to reorganize the table and compact any wasted space. ) There is nothing MySQL has that will indicate the progress of OPTIMIZE TABLE;. Currently I am using mysql 5. bid where a. In order to use it to update fulltext index statistics, the innodb_optimize_fulltext_only system variable must be set to 1. The same table gets a single notification when the current user 14 is followed by someone, with an entry leader_id 0 and notifiable_id 14 (id 3 in table). Tried different approaches like batch deletes (described above). 4” . Apr 12, 2013 · 0. 3. answered Oct 8, 2012 at 2:51. Feb 7, 2018 · This is the first time we've worked with MySQL and we're still learning the expected behaviours. slow-query_log_file = /var/log/mysql-slow. The analyzer in phpMyAdmin recommends that I run OPTIMIZE TABLE on my tables. Oct 20, 2009 · I use 'optimize table ' to maintein a table very Monday and Friday, usaually it needs 1 hour normally , but sometime ,the 'optimize table' operation take serval hours or longer, today the 'optimize table ' runs for near 10 hours and not finish . rogerdpack. To execute this statement, you need SELECT and INSERT privileges. This section describes when MySQL can use an index to satisfy an ORDER BY clause, the filesort operation used when an index cannot be used, and execution plan information available from the optimizer about ORDER BY . In my company we have tables about 2-3 gb. Otherwise, MySQL spends the time flushing tables with leftover dirty page out of the buffer pool. You may have to go the OS using Windows Explorer and look for a growing tmp table. Nov 20, 2014 · It is taking too long. Jul 21, 2019 · Do the compress and uncompress in the client.
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