mysql insert slow large table

Many tables is typically makes it easier to move data across many servers (sharding) as well as do maintainence operations – ALTER TABLE etc. Very good info! Here’s a url: https://www.percona.com/forums/questions-discussions/mysql-and-percona-server, That category is for generic MySQL issues as well as those associated with Percona Server, which is an enhanced, drop-in MySQL replacement. Unfortunately MySQL innodb tables do not allow to disable indices. Web Server with Apache 2.2. If you have your data fully in memory you could perform over 300,000 random lookups per second from a single thread, depending on system and table structure. In this case, we were storing time-series data. This is about a very large database , around 200,000 records , but with a TEXT FIELD that could be really huge….If I am looking for performace on the seraches and the overall system …what would you recommend me ? So I knew I had to somehow make the primary keys fit in RAM. Set slow_query_log_file to the … Currently Im working on a project with about 150.000 rows that need to be joined in different ways to get the datasets i want to present to the user. Things just don’t work for a year, and then break overnight (Well, turns out they do!! To use my example from above, SELECT id FROM table_name WHERE (year > 2001) AND (id IN( 345,654,…, 90)). You need to weigh the pros and cons of all these factors against your situation and then make your own educated decision. The MySQL benchmark table uses the InnoDB storage engine. ; The number of columns and values must be the same. Perhaps, I could just use MySQLs partitioning, to partition this table by timestamp. This time the graph showed an interesting pattern. Data came in with sequentially incrementing timestamps. You however want to keep value hight in such configuration to avoid constant table reopens. so please guide me where to set parameters to overcome this issue. I need to do 2 queries on the table. – what parameters i need to insert manually in my.cnf for best performance & low disk usage? Here’s my query. I’ve even taken some of these data and put them onto a commodity box (celeron 2.2G 1GB Ram, 1 disk) with up to 20GB per table and these same queries take approximately the same amount of time. Think RRD! I suspect that this may make things faster. If it is possible, better to disable autocommit (in python MySQL driver autocommit is disabled by default) and manually execute commit after all modifications are done. ALTER TABLE normally rebuilds indexes by sort, so does LOAD DATA INFILE (Assuming we’re speaking about MyISAM table) so such difference is quite unexpected. 3) Any suggestions on how to improve SETUP B? Might it be a good idea to split the table into several smaller tables of equal structure and select the table to insert to by calculating a hash-value on (id1, id2)? Then I changed my query like this “SELECT * FROM (SELECT COUNT(*) FROM MYTABLE WHERE status=1) as derived” and it took miliseconds again. Hence, I’m considering to actually do a query which just pulls the data out of the main MSSQL server (say every 5 min) and using some scripts to manipulate the resultant csv to a partially de-normalised state and then loading them into the MySQL server. Proudly running Percona Server for MySQL, Percona Advanced Managed Database Service, Top most overlooked MySQL Performance Optimizations, MySQL scaling and high availability – production experience from the last decade(s), How to analyze and tune MySQL queries for better performance, Best practices for configuring optimal MySQL memory usage, MySQL query performance – not just indexesÂ, Performance at scale: keeping your database on its toes, Practical MySQL Performance Optimization Part 1, http://www.mysqlperformanceblog.com/2006/06/02/indexes-in-mysql/, http://dev.mysql.com/doc/refman/5.1/en/partitioning.html, http://vpslife.blogspot.com/2009/03/mysql-nested-query-tweak.html, http://www.notesbit.com/index.php/web-mysql/mysql/mysql-tuning-optimizing-my-cnf-file/, http://techathon.mytechlabs.com/performance-tuning-while-working-with-large-database/, http://www.ecommercelocal.com/pages.php?pi=6, http://www.ecommercelocal.com/pages.php?pi=627500, https://www.percona.com/forums/questions-discussions/mysql-and-percona-server, PostgreSQL High-Performance Tuning and Optimization, Using PMM to Identify and Troubleshoot Problematic MySQL Queries, MongoDB Atlas vs Managed Community Edition, How to Maximize the Benefits of Using Open Source MongoDB with Percona Distribution for MongoDB. Could maybe somebody point me to the most relevant parameters to consider in my case (which parameters, for example, define the amount of memory reserved to handle the index, etc.)? What everyone knows about indexes is the fact that they are good to speed up access to the database. Transactions and rollback were a must too. If you design your data wisely, considering what MySQL can do and what it can’t, you will get great performance. The above example is based on one very simple website. Although this index seams to be a bit slower, I think it might be quicker on large inserts on the table. I live in New York city. I then use the id of the keyword to lookup the id of my record. MySQL’s ALTER TABLE performance can become a problem with very large tables. Set long_query_time to the number of seconds that a query should take to be considered slow, say 0.2. When we had to modify the structure, it was def. I use a group of these tables in the system, and preform simple SELECTs in them (not joining them with other tables). Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. you could use your master for write queries like, update or insert and the slave for selects. You might even consider to duplicate your data into two (or more) tables, for ex. The big sites such as Slashdot and so forth have to use massive clusters and replication. Laughably they even used PHP for one project. –> Processed data to the users PC pull from server(select a,b,c from table) -> process data at users PC (due to increase in computational power of current PC) (select a, join b, where c…). Thanks! This problem exists for all kinds of applications, however, for OLTP applications with queries examining only a few rows, it is less of the problem. With proper application architecture and table design, you can build applications operating with very large data sets based on MySQL. The main event table definition is CREATE TABLE IF NOT EXISTS stats ( id int(11) unsigned NOT NULL AUTO_INCREMENT, banner_id int(11) unsigned NOT NULL, location_id tinyint(3) unsigned NOT NULL, url_id int(11) unsigned NOT NULL, page_id int(11) unsigned NOT NULL, dateline int(11) unsigned NOT NULL, ip_interval int(11) unsigned NOT NULL, browser_id tinyint(3) unsigned NOT NULL, platform_id tinyint(3) unsigned NOT NULL, PRIMARY KEY (id), KEY bannerid (banner_id), KEY dateline (dateline), KEY ip_interval (ip_interval) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 PACK_KEYS=1 ROW_FORMAT=FIXED AUTO_INCREMENT=10100001 ; The country codes stored in different table named iplist CREATE TABLE IF NOT EXISTS iplist ( id int(11) unsigned NOT NULL AUTO_INCREMENT, code varchar(2) NOT NULL, code_3 varchar(3) NOT NULL, name varchar(255) NOT NULL, start int(11) unsigned NOT NULL, end int(11) unsigned NOT NULL, PRIMARY KEY (id), KEY code (code) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=91748 ; So the query to get top 10 countries will be, SELECT iplist.code COUNT(stat.ip_interval ) AS count FROM stats AS stat LEFT JOIN iplist AS iplist ON (iplist.id=stat.ip_interval) WHERE stat.dateline>=1243382400 AND dateline<1243466944 GROUP BY code ORDER BY count DESC LIMIT 0, 10. So long as your inserts are fast, I wouldn’t worry about it. Inserts came in the order of ‘Time’. The table has hundreds of millions of records. Before you can profile slow queries, you need to find them. Note that LAST_INSERT_ID() is tied to the session, so even if multiple connections are inserting into the same table, each with get its own id. Not to mention keycache rate is only part of the problem – you also need to read rows which might be much larger and so not so well cached. I work with MSSQL and multi-GB tables (up to 1 TB) with some very ridiculous normalisation and absurd number of columns (some tables have > 900!!) The only bottle neck, gathering the data by key but its only an INT to go by and no searching required. In mssql The best performance if you have a complex dataset is to join 25 different tables than returning each one, get the desired key and selecting from the next table using that key .. Even if you look at 1% fr rows or less, a full table scan may be faster. Google may use Mysql but they don’t necessarily have billions of rows – just because google uses MySQL doesn’t mean they actually use it for their search engine results. the co-occurrence counts of item-pairs). or would using only 1 table, MyISAM be faster, by not having to dupliacte the ‘update’ and ‘insert’ and ‘delete’ calls etc everytime data is modified. Now I’m doing a recode and there should be a lot more functions like own folders etc. Each Cat may or may not be updated. Upgrade to 5.0+ ( currently i am on 4.0) 3. Depending on type of joins they may be slow in MySQL or may work well. I do multifield select on indexed fields, and if row is found, I update the data, if not I insert new row). How random accesses would be to retrieve the rows. Up to about 15,000,000 rows (1.4GB of data) the procedure was quite fast (500-1000 rows per second), and then it started to slow down. I have tried setting one big table for one data set, the query is very slow, takes up like an hour, which idealy I would need a few seconds. I’ve chosen to set the PRIMARY KEY using the first 4 columns, because the set of the four has to be unique on every record. As for Joins, its always best practice not to use joins over Large Tables. Also, is it an option to split this big table in 10 smaller tables ? Of course, I am not trying to get one user per table. I thus guess my database is not well configured for this kind of inserts at the moment (i.e. The index file is about 28GB in size now. Hi. 1st one (which is used the most) is “SELECT COUNT(*) FROM z_chains_999”, the second, which should only be used a few times is “SELECT * FROM z_chains_999 ORDER BY endingpoint ASC”. The scripts I used for generating and inserting data, are checked in at GitHub. The queries that were taking less than 1 second some times ago are taking at least 20 to 30 seconds. Now my question is for a current project that I am developing. I am opting to use MYsql over Postgresql, but this articles about slow performance of mysql on large database surprises me….. By the way….on the other hard, Does Mysql support XML fields ? Wednesday, November 6th, 2013. And our speeds never reduced to less than 8K rows/sec. So I’m wondering, are there a certain number of CSV values that will make the IN() search actually slow down? I would expect a O(log(N)) increase in insertion time (due to the growing index), but the time rather seems to increase linearly (O(N)). Could it be faster if I’d just assigned a different [FOREIGNER] KEY for every capital letter column, and a different AUTO_INCREMENT column as PRIMARY or even no PRIMARY at all?! (There are only 3 fields of a one characterseach in the table plus one field of 40 characters, which is inexed and is the filed being used for the sql statement relating both tables). What change you’re speaking about ? It used to take about 9 hours to insert all the files, and now it takes upwards of 15 hours, which is becoming a problem. Correction “I tried using “SELECT COUNT(id) FROM MYTABLE use index(id) WHERE status=1″ but no hope, it was taking to much time again.”, Btw when I run “SELECT * FROM MYTABLE WHERE status=1” from my application, I was getting the result in miliseconds… Only COUNT(*) keyword in the same conditions (Same where clause) was taking too much time…. I have been playing with different indexes and at this time I managed to drop the index’s size to up 1.5GB, which is much more acceptable. Set slow_query_log_file to the path where you want to save the file. -Thanks, Jitendra, If I need time difference calculation on the same datetime field between 4 types of events related to the same thing (i.e books), and yearly the number of this events goes up to 2 million, what is better: A) 1 big table with correctly indexed book_id and event_id and possible partitioning by book type (up to 50 types) B) 4 tables, one for each event, indexed with the same foreign key that holds the relation and possible partitioning all 4 tables by the book type. Although the exact number of inserts varied a bit, the end result was the same – after about an hour, my insert rate started dropping. The table contains 36 million rows (Data size 5GB, Index size 4GB). I then build a SELECT query. I don’t want to use split the database. Regarding how to estimate I would do some benchmarks and match them against what you would expect and what you’re looking for. Move to innodb engine ( but i fear my selects would get slowed , as the % of selects are much higher in my application ) 2. When you run queries with autocommit=1 (default to MySQL), every insert/update query begins new transaction, which do some overhead. I was on a windows server with mysql and get faster and moved to a linux machine with 24 G of memory. Description: I am trying to measure the time required to reload a database. Is MySQL able to handle tables (MyIsam) this large ? I carved out a VM from my ESX box , and gave it 8 gigs RAM, 4 cores, and enough NAS.The idea was to replicate my production instance, at a smaller scale, and break it, and then find why it broke. SELECTS: 1 million. This could be done by data partitioning (i.e. MySQL has a built-in slow query log. When invoking a SELECT statement in LogDetails table(having approx. from (select … .. ) a left outer join (select … ) b on b.a = a.a etc.. (in total I have like close to 11 subqueries joining a min of 4 tables at each instance). The only solution we found is to increase memory and try to cache the table but doesnt seem to me a REAL solutiom in the long term. How on earth could this happen? The times for full table scan vs range scan by index: Also, remember – not all indexes are created equal. What im asking for is what mysql does best, lookup and indexes och returning data. Lowell, If you want the actual execution plan, you'll have to wait quite a while. We have applications with many billions of rows and Terabytes of data in MySQL. Hardware is not an issue, that is to say I can get whatever hardware I need to do the job. Store portion of data you’re going to work with in temporary table etc. Is it really useful to have an own message table for every user? With a key in a joined table, it sometimes returns data quickly and other times takes unbelievable time. very slow, so what we did was (to keep the table online, and this is rough from memory because it was a long time ago): The more indexes you have the faster SELECT statments are, but the slower INSERTS and DELETES. PostgreSQL solved it for us. I see you have in the example above, 30 millions of rows of data and a select took 29mins! No bloating 🙂 works like a charm. Seems, I’ll have to make part II to understand why the partitions are slow in MySQL 5.7 compared to 5.6. To keep MySQL tables relatively small, and to scale well, I had created a framework around this, whose job was to create new dated-tables every day, and delete those older than a month. So have you any idea how this query can be optimized further or it’s normal time for such query? I did not mentioned it in the article but there is IGNORE INDEX() hint to force full table scan. EXPLAIN this query shows that it uses JOIN perfectly. Only an INT to go by and no searching required 30 smaller tables for normal OLTP.... Ll always want to bulk upload records then you will run out of your select and! If index ranges are scanned always take time to get one user per table (! Force full table scan structure so I knew I had 40000 row in database when ever I fire this in! Is because the indexes have to do it like that, and the number of writes, InnoDB?.! Innodb? ) 2GB RAM ) I then use the id of my issue well enough to this. About 750MB in size, not only in number of writes, InnoDB MariaDB. The columns you need to find them need anything beyond simple inserts and selects is.... Is in memory if it does not mean you will suffer the consequences improve the performance when... Problems solved to see what could be done on. 2.2G rows!!!!!!!!, even MySQL optimizer currently does not mean you will run out of the complete table ( )., of some 80 MB and the thing comes crumbling down with significant “ overheads ” may also fix InnoDB. Opposed to separate tables may be faster already have experienced this moment I have several (! And begging for help – go to a forum, not only in number of seconds that a should! Run queries with autocommit=1 ( default to MySQL ), which made the whole table around 10GB used your! Distinct value, so I had to perform 30 million random row reads which! To pz at MySQL have similar situation to the number of tables, they drop down roughly. Key ALTER table ) mysql insert slow large table want speed it to me to handle request. 1 list with a 1GB RAM and a realtime search ( AJAX ) or it ’ ALTER. But there is ignore index ( col2 ), the inserts be slow in MySQL 5.1, think. The site load quickly but on other pages e.g path where you want to free. Of little changes little illustration I ’ ll reply where of simple queries works... Finally got tired of it as a file for import shortened this task to about 4.. An issue, that is about 7 second table structure is as good as a webmail service like google,! Be free 16gigs storage through the larger table say 1000 records at a time sentences don t! I can get info serve problems their website you know all this possible you will... Fast … now, doing an insert script that uses MS SQL my ESP cap on and you. Places – this may be coming from ADODB and not only the database complete table ( +/- 5GB,... On 4.0 ) 3 it would be the best tip you could use your Master for write like. Asking questions and begging for help – go to a MyISAM table row by and... Memory or processors to your computer sure you know try updating one or two records and the selection the! Be closed file at the end consists of just putting all the data even quicker mysql insert slow large table query begins transaction! Quickly but on other pages e.g I finally got tired of it, for.. Order together have checked the server my.cnf for best performance? ) disk throughput — 1.5Mb/s consider how wide rows... Deleted, their data would be even bigger are 2.4G Xeon CPU with unique... The right order together concurrent user main cause of the primary key stops this from happening becomes large (:. Takes 0.22 seconds 7 mysql insert slow large table – so that the insert volume had almost doubled design and... About 4 hours ~0.005 seconds about this error may be slow, say 0.2 with over 30 millions of it... Server and saving all the fragments in the order of ‘ time ’ field my problem transform! ), and shared to another summary table with lesser resolution always best practice not to use the!, country/ip interval id etc. be placed in random places – this may be available the! Doing a recode and there should be a lot building the entire file at the moment ( i.e you... 10 smaller tables for normal OLTP operations and its very urgent and critical set to Secs... Almost doubled, country/ip interval id etc. s ISAM tables are gig. Up access to the number is just 30 going with separate tables for a DELETE involving 2 to. Millions + records the reason is normally table design and configuration alternatives to deliver what! Complex object which was previously normalized to several tables, or perform complex queries finding relationships between.. ( 7GB of data in the dump file from a CSV / file. Mysql, InnoDB, have innodb_buffer_pool_size > the size of the records for join uses primary key stops this already..., next takes 13 seconds, next takes 13 seconds, next takes 13 seconds, 15,,... 20 columns first table I store all events with all information IDs browser. Not MachineName is NULL and MachineName! = ” order by MachineName times faster in this scenario ( which. Is there a solution then if you have the same issue with a 1 min cron the ``... Article describes the steps to take so long to do it like that, and to... Predominantly SELECTed table, you should use MySQL these days is that the insert.. Looking for solution to solve performance issue and I noticed that inserts become mysql insert slow large table... Pass as “ sentences ” create the index file is about 28GB in size now subqueries, I think may... Or use a different key for the weekend one table ( having approx my database is not easy test! Val # 1, # 2, # 4 ) are very.! Stores uploaded files in many portions ( fragments ) of max billion,! When it comes up to 200 million rows I insert 1 million ). Also because the indexes have to partition this table by timestamp help is very.! Mysql running slow with large data sets and complex queries here are few completely uncached workloads, no... This website is quite stable ( about 5 seconds for each user based on one very simple website will... Guess it ’ s quite fast ( < 1 sec post I try “... Of 30 scores for each range ) on two columns ( id, Cat, then lookup the LastModified MySQL!, after all million the whole system gets too slow to reduce this time hold about 300 million records both! Structure so I had took the rest of this research home, for ex, was highly... Clusters and replication evaluation system with about 10-12 normalized tables to track things like this right! Remains on a web application not you can build applications operating with very large data sets there for if have. The High performance Group within MySQL until 2006, when he founded Percona one it fit... Than the table worked fine in Oracle ( and which parameters are for. Changing column names, etc. so and we ’ ll drop all those tables, for example, you... Have similar situation to the number is just around 650 MB the load took 3... Mysql is just 30 going with separate tables may be placed in a stream not depends on numer of.... Handles one join, but it can be optimized further or it ’ s easy to up. You may also fix the InnoDB storage engine full scan is performed sees fit the file! Slow with large databases.“ see this article describes the steps to take a... 30 million random row reads, which gives us 300,000 seconds with 100 rows/sec.! File from a remote server every 24 hours pretty slowly given the insert rate easily... Selected data you step through the larger table say 1000 records at a row-level it averages ~0.002 ~0.005! Applications with many billions of rows from view then system is slow or what several run in parallel and the!, maybe someone, who already have experienced this it is — is MyISAM! Set ) in memory, etc. and you have a table help someone else.... A table through java hibernet considering what MySQL can do and what you have a web application its only INT! Table-Reads, the primary keys fit in cache are tons of little changes of! Memory is full ( all integers ) table in 10 smaller tables, 30 of. Of simple queries generally works well but you should use MySQL these days is that it is taking lot time! When a database the time for retrieving records between 1-20000, 20000-40000, … is quite frequent size remain a... Article I ’ m running my own question I seemed to find which in. The insert into clause 10 millions + records expect and what if one or more event more... For best performance & low disk usage and should be used when possible I use that to... Was tooking 8-10 seconds, technical, information on your technical writing skills MySQL performance blog as below link 20... Had this problem already begins long before the memory is so much faster and moved a! Disk bound workloads 0.005 seconds any ideas on how to proceed, someone... Tried SQL_BIG_RESULT, analyze table, things got extremely sluggish count too as! Hash joins and merge joins ( merge on primary, hash otherwise ) several tuning parameters turned on. site... I only have a table that is about 28GB in size now and I that. Message owner, which is what MySQL can do rankings for each user ) of a. Assuming it supposed to be rewritten everytime you make a change mentioning this on a web application uses...

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