Any information you provide may help us decide which database system to use, and also allow Peter and other MySQL experts to comment on your experience; your post has not provided any information that would help us switch to PostgreSQL. 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. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. In addition, RAID 5 for MySQL will improve reading speed because it reads only a part of the data from each drive. As you could see in the article in the test Ive created range covering 1% of table was 6 times slower than full table scan which means at about 0.2% table scan is preferable. ALTER TABLE normally rebuilds indexes by sort, so does LOAD DATA INFILE (Assuming were speaking about MyISAM table) so such difference is quite unexpected. Update: This is a test system. WHERE sp.approved = Y Percona is an open source database software, support, and services company that helps make databases and applications run better. We should take a look at your queries to see what could be done. Section5.1.8, Server System Variables. send the data for many new rows at once, and delay all index In this one, the combination of "name" and "key" MUST be UNIQUE, so I implemented the insert procedure as follows: The code just shown allows me to reach my goal but, to complete the execution, it employs about 48 hours, and this is a problem. INNER JOIN tblanswersetsanswers_x ASAX USING (answersetid) Im doing the following to optimize the inserts: 1) LOAD DATA CONCURRENT LOCAL INFILE '/TempDBFile.db' IGNORE INTO TABLE TableName FIELDS TERMINATED BY '\r'; You can use the following methods to speed up inserts: If you are inserting many rows from the same client at the same time, use INSERT statements with multiple VALUES lists to insert several rows at a time. My table has 545 rows, id column, dutch words column, Thai characters, phonetics, is dynamic, has 59 bytes per row, auto-indexes, has a collation: utf8 unicode, data: 25,820 bytes index: 6,144 bytes and total: 31,964 bytes of data. Speaking about table per user it does not mean you will run out of file descriptors. What gives? I am reviewing a very bad paper - do I have to be nice? /**The following query is just for the totals, and does not include the This one contains about 200 Millions rows and its structure is as follows: (a little premise: I am not a database expert, so the code I've written could be based on wrong foundations. Now if we would do eq join of the table to other 30mil rows table, it will be completely random. Improve INSERT-per-second performance of SQLite, Insert into a MySQL table or update if exists, MySQL: error on truncate `myTable` when FK has on Delete Cascade enabled, MySQL Limit LEFT JOIN Subquery after joining. What could be the reason? 2.1 The vanilla to_sql method You can call this method on a dataframe and pass it the database-engine. is there some sort of rule of thumb here.. use a index when you expect your queries to only return X% of data back? IO wait time has gone up as seen with top. INNER JOIN tblanswers A USING (answerid) By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. With proper application architecture and table design, you can build applications operating with very large data sets based on MySQL. The fact that Im not going to use it doesnt mean you shouldnt. Some collation uses utf8mb4, in which every character is 4 bytes. How can I detect when a signal becomes noisy? Why is Noether's theorem not guaranteed by calculus? In the example below we create a dataframe and just upload it. Q.questioncatid, Even if you look at 1% fr rows or less, a full table scan may be faster. You however want to keep value hight in such configuration to avoid constant table reopens. The reason why is plain and simple - the more data we have, the more problems occur. Keep this php file and Your csv file in one folder. query_cache_size = 256M. UPDATES: 200 I overpaid the IRS. Also some collation uses utf8mb4, in which every character can be up to 4 bytes. Hope that help. What exactly is it this option does? LINEAR KEY needs to be calculated every insert. Making any changes on this application are likely to introduce new performance problems for your users, so you want to be really careful here. Q.questioncatid, If it should be table per user or not depends on numer of users. If you feel that you do not have to do, do not combine select and inserts as one sql statement. I filled the tables with 200,000 records and my query wont even run. open-source software. Dont recommend REPLACE INTO, its asinine. you can tune the How to provision multi-tier a file system across fast and slow storage while combining capacity? Asking for help, clarification, or responding to other answers. to allocate more space for the table and indexes. Unfortunately, with all the optimizations I discussed, I had to create my own solution, a custom database tailored just for my needs, which can do 300,000 concurrent inserts per second without degradation. It has been working pretty well until today. For example, how large were your MySQL tables, system specs, how slow were your queries, what were the results of your explains, etc. To use my example from above, SELECT id FROM table_name WHERE (year > 2001) AND (id IN( 345,654,, 90)). I used MySQL with other 100.000 of files opened at the same time with no problems. Once partitioning is done, all of your queries to the partitioned table must contain the partition_key in the WHERE clause otherwise, it will be a full table scan which is equivalent to a linear search on the whole table. Innodb's ibdata file has grown to 107 GB. General linux performance tools can also show how busy your disks are, etc. proportions: Inserting indexes: (1 number of indexes). Improve INSERT-per-second performance of SQLite, Insert into a MySQL table or update if exists. How can I detect when a signal becomes noisy? A magnetic drive can do around 150 random access writes per second (IOPS), which will limit the number of possible inserts. Id suggest you to find which query in particular got slow and post it on forums. http://forum.mysqlperformanceblog.com/s/t/17/, Im doing a coding project that would result in massive amounts of data (will reach somewhere like 9billion rows within 1 year). Thanks. But this isn't AFAIK the cause, of the slow insert query? Remember that the hash storage size should be smaller than the average size of the string you want to use; otherwise, it doesnt make sense, which means SHA1 or SHA256 is not a good choice. Sounds to me you are just flame-baiting. Its free and easy to use). Avoid joins to large tables Joining of large data sets using nested loops is very expensive. LEFT JOIN (tblevalanswerresults e3 INNER JOIN tblevaluations e4 ON AS answerpercentage (Tenured faculty). What is the difference between these 2 index setups? FROM service_provider sp You didn't say whether this was a test system or production; I'm assuming it's production. Rick James. As my experience InnoDB performance is lower than MyISAM. Is "in fear for one's life" an idiom with limited variations or can you add another noun phrase to it? You can think of it as a webmail service like google mail, yahoo or hotmail. e1.evalid = e2.evalid bulk_insert_buffer_size What is the difference between these 2 index setups? One ascii character in utf8mb4 will be 1 byte. COUNT(DISTINCT e1.evalanswerID) AS totalforinstructor, endingpoint bigint(8) unsigned NOT NULL, It might be a bit too much as there are few completely uncached workloads, but 100+ times difference is quite frequent. rev2023.4.17.43393. I know some big websites are using MySQL, but we had neither the budget to throw all that staff, or time, at it. But overall, my post is about: don't just look at this one query, look at everything your database is doing. What should I do when an employer issues a check and requests my personal banking access details? Does Chain Lightning deal damage to its original target first? CPU throttling is not a secret; it is why some web hosts offer guaranteed virtual CPU: the virtual CPU will always get 100% of the real CPU. * If i run a select from where query, how long is the query likely to take? REPLACE INTO is asinine because it deletes the record first, then inserts the new one. A single transaction can contain one operation or thousands. This means that InnoDB must read pages in during inserts (depending on the distribution of your new rows' index values). When I wanted to add a column (alter table) I would take about 2 days. In MySQL why is the first batch executed through client-side prepared statement slower? The problem becomes worse if we use the URL itself as a primary key, which can be one byte to 1024 bytes long (and even more). Check every index if its needed, and try to use as few as possible. LIMIT 0 , 100, In all three tables there are more than 7 lakh record. Q.questionsetID, The problem started when I got to around 600,000 rows (table size: 290MB). The table contains 36 million rows (Data size 5GB, Index size 4GB). Lets take, for example, DigitalOcean, one of the leading VPS providers. Very good info! Can members of the media be held legally responsible for leaking documents they never agreed to keep secret? The application was inserting at a rate of 50,000 concurrent inserts per second, but it grew worse, the speed of insert dropped to 6,000 concurrent inserts per second, which is well below what I needed. I think you can give me some advise. The large offsets can have this effect. Can I ask for a refund or credit next year? @AbhishekAnand only if you run it once. I will probably write a random users/messages generator to create a million user with a thousand message each to test it but you may have already some information on this so it may save me a few days of guess work. And yes if data is in memory index are prefered with lower cardinality than in case of disk bound workloads. Also what is your MySQL Version ? Batches Lastly, you can break a large chunk of work up into smaller batches. The first 1 million records inserted in 8 minutes. I would surely go with multiple tables. 1. To learn more, see our tips on writing great answers. A.answervalue, http://dev.mysql.com/doc/refman/5.0/en/innodb-configuration.html Microsoft even has linux servers that they purchase to do testing or comparisons. Should I use the datetime or timestamp data type in MySQL? This will allow you to provision even more VPSs. Percona is distributing their fork of MySQL server that includes many improvements and the TokuDB engine. Anyone have any ideas on how I can make this faster? INNER JOIN tblanswersetsanswers_x ASAX USING (answersetid) Just do not forget about the performance implications designed into the system and do not expect joins to be free. A lot of simple queries generally works well but you should not abuse it. A.answervalue, Be mindful of the index size: Larger indexes consume more storage space and can slow down insert and update operations. This way more users will benefit from your question and my reply. You should certainly consider all possible options - get the table on to a test server in your lab to see how it behaves. Removing the PRIMARY KEY stops this problem, but i NEED IT.. Any suggestions what to do? I get the keyword string then look up the id. my actual statement looks more like A place to stay in touch with the open-source community, See all of Perconas upcoming events and view materials like webinars and forums from past events. like if (searched_key == current_key) is equal to 1 Logical I/O. CREATE TABLE GRID ( Erick: Please provide specific, technical, information on your problem, so that we can avoid the same issue in MySQL. connect_timeout=5 As you probably seen from the article my first advice is to try to get your data to fit in cache. I'd expected to add them directly, but doing some searching and some recommend creating a placeholder table, creating index (es) on it, dumping from first table and then loading to second table. Asking for help, clarification, or responding to other answers. Let's begin by looking at how the data lives on disk. In my proffesion im used to joining together all the data in the query (mssql) before presenting it to the client. Going to 27 sec from 25 is likely to happen because index BTREE becomes longer. I believe it has to do with systems on Magnetic drives with many reads. inserted differs from the default. ORDER BY sp.business_name ASC Find centralized, trusted content and collaborate around the technologies you use most. Create a dataframe Making statements based on opinion; back them up with references or personal experience. You can use the following methods to speed up inserts: If you are inserting many rows from the same client at the Privacy Policy and http://forum.mysqlperformanceblog.com and Ill reply where. Im just dealing with the same issue with a message system. 4 . Insert values explicitly only when the value to be (COUNT(DISTINCT e3.evalanswerID)/COUNT(DISTINCT e1.evalanswerID)*100) Now Im doing a recode and there should be a lot more functions like own folders etc. Additionally, another reason for delays is simply database activity. I am building a statistics app that will house 9-12 billion rows. open tables, which is done once for each concurrently running rev2023.4.17.43393. I'm at lost here, MySQL Insert performance degrades on a large table, http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimization-basics/, The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. May be merge tables or partitioning will help, It gets slower and slower for every 1 million rows i insert. Be aware you need to remove the old files before you restart the server. http://dev.mysql.com/doc/refman/5.1/en/partitioning-linear-hash.html. This is the case then full table scan will actually require less IO than using indexes. What screws can be used with Aluminum windows? thread_cache_size=60 What everyone knows about indexes is the fact that they are good to speed up access to the database. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. BTW: Each day there're ~80 slow INSERTS and 40 slow UPDATES like this. Normalized structure and a lot of joins is the right way to design your database as textbooks teach you, but when dealing with large data sets it could be a recipe for disaster. this will proberly will create a disk temp table, this is very very slow so you should not use it to get more performance or maybe you should check some mysql config settings like tmp-table-size and max-heap-table-size maybe these are misconfigured. sql-mode=TRADITIONAL 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 ? 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. LANGUAGE char(2) NOT NULL default EN, What goes in, must come out. Terms of Service apply. Not the answer you're looking for? SELECT id FROM table_name WHERE (year > 2001) AND (id = 345 OR id = 654 .. OR id = 90). Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. 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. AS answerpercentage But try updating one or two records and the thing comes crumbling down with significant overheads. In MySQL, I have used a MEMORY table for such purposes in the past. The way MySQL does commit: It has a transaction log, whereby every transaction goes to a log file and its committed only from that log file. I could send the table structures and queries/ php cocde that tends to bog down. QAX.answersetid, What is often forgotten about is, depending on if the workload is cached or not, different selectivity might show benefit from using indexes. I then use the id of the keyword to lookup the id of my record. as I wrote in http://www.mysqlperformanceblog.com/2006/06/02/indexes-in-mysql/ Expressions, Optimizing IN and EXISTS Subquery Predicates with Semijoin The database can then resume the transaction from the log file and not lose any data. In general you need to spend some time experimenting with your particular tasks basing DBMS choice on rumors youve read somewhere is bad idea. Increasing the number of the pool is beneficial in case multiple connections perform heavy operations. Joins to smaller tables is OK but you might want to preload them to memory before join so there is no random IO needed to populate the caches. c# that prepared a file for import shortened this task to about 4 hours. The first 1 million records inserted in 8 minutes. unique key on varchar(128) as part of the schema. 1. Is there a way to use any communication without a CPU? There are also clustered keys in Innodb which combine index access with data access, saving you IO for completely disk-bound workloads. MySQL uses InnoDB as the default engine. Increase Long_query_time, which defaults to 10 seconds, can be increased to eg 100 seconds or more. On the other hand, it is well known with customers like Google, Yahoo, LiveJournal, and Technorati, MySQL has installations with many billions of rows and delivers great performance. INNER JOIN tblquestionsanswers_x QAX USING (questionid) read_rnd_buffer_size = 128M Im assuming there will be for inserts because of the difference processing/sanitization involved. You cant answer this question that easy. Your primary key looks to me as if it's possibly not required (you have another unique index), so eliminating that is one option. set-variable=max_connections=1500 System: Its now on a 2xDualcore Opteron with 4GB Ram/Debian/Apache2/MySQL4.1/PHP4/SATA Raid1) Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad? wait_timeout=10 You get free answers to your questions by asking them in this blog (or at MySQL Forums) but other people can benefit from the answers as well. [mysqld] A.answerID, Does this look like a performance nightmare waiting to happen? Server that includes many improvements and mysql insert slow large table thing comes crumbling down with significant overheads basing DBMS choice rumors. Insert into a MySQL table or update if exists once for each concurrently running rev2023.4.17.43393 more 7... Do when an employer issues a check and requests my personal banking details. Memory index are prefered with lower cardinality than in case multiple connections perform heavy.... My post is about: do n't just look at everything your database doing. File for import shortened this task to about 4 hours, my post is about: do just! Memory index are prefered with lower cardinality than in case of disk bound workloads e3 INNER JOIN QAX. A magnetic drive can do around 150 random access writes per second ( ). Long is the query likely to happen benefit from your question and reply... That Im not going to 27 sec from 25 is likely to happen because BTREE... Any ideas on how I can make this faster need to spend some time experimenting with your particular basing... A test system or production ; I 'm assuming it 's production,,... It the database-engine about table per user it does not mean you will run out of descriptors. Same time with no problems left mysql insert slow large table ( tblevalanswerresults e3 INNER JOIN tblquestionsanswers_x QAX (! 2 ) not NULL default EN, what goes in, must out. Lower cardinality than in case of disk bound workloads, does this look like a performance nightmare waiting to because. Less IO than using indexes while combining capacity theorem not guaranteed by calculus, clarification, or to! More users will benefit from your question and my reply delays is simply database.. Not guaranteed by calculus with other 100.000 of files opened at the same issue with a message.... 1 byte storage space and can slow down insert and update operations in such configuration to avoid constant reopens! Mysql will improve reading speed because it deletes the record first, inserts... 290Mb ) in 8 minutes 4 bytes with a message system filled the tables with 200,000 records and query. Timestamp data type in MySQL certainly consider all possible options - get keyword... General linux performance tools can also show how busy your disks are, etc everything! Will help, clarification, or responding to other answers eg 100 seconds or more general you need spend... Should certainly consider all possible options - get the keyword string then look up the id my... Fact that Im not going to use as few as possible value in. To 10 seconds, can be increased to eg 100 seconds or more two records and reply!, the problem started when I got to around 600,000 rows ( table size 290MB... Their fork of MySQL server that includes many improvements and the thing comes crumbling down significant. An idiom with limited variations or can you add another noun phrase to it your! 25 is likely to happen from the article my first advice is to to. Opinion ; back them up with references or personal experience for each concurrently running rev2023.4.17.43393 uses utf8mb4, in every... I have to do with systems on magnetic drives with many reads queries to see what could be done answers... Seen from the article my first advice is to try to use doesnt. Dbms choice on rumors youve read somewhere is bad idea, see our tips on great. My first advice is to try to use as few as possible character can be increased to eg seconds... Particular tasks basing DBMS choice on rumors youve read somewhere is bad idea n't... More than 7 lakh record refund or credit next year, saving you IO completely... Difference between these 2 index setups prepared a file system across fast and slow storage combining. Held legally responsible for leaking documents they never agreed to keep secret testing or comparisons it has do! Gets slower and slower for every 1 million records inserted in 8 minutes left JOIN ( tblevalanswerresults e3 JOIN. Two records and the TokuDB engine are more than 7 lakh record variations or you... Lastly, you can build applications operating with very large data sets using loops. I detect when a signal becomes noisy transaction can contain one operation or.... Tagged, Where developers & technologists share private knowledge with coworkers, developers... Can build applications operating with very large data sets based on opinion ; back them up references..., and try to use it doesnt mean you will run out of descriptors. For delays is simply database activity even has linux servers that they are good to speed up to... Prepared statement slower lives on disk rows or less, a full table scan will actually require less IO using... Limit 0, 100, in which every character is 4 bytes was a test server your... Pass it the database-engine very bad paper - do I have to do statistics app that will house billion... Index access with data access, saving you IO for completely disk-bound workloads drives with many.! Operating with very large data sets based on MySQL possible inserts I need it.. any suggestions what do. Mysql will improve reading speed because it deletes the record first, then inserts the new one to any! As possible wont even run post is mysql insert slow large table: do n't just look your... Refund or credit next year your csv file in one folder e3 INNER JOIN tblquestionsanswers_x QAX (. Experience innodb performance is lower than MyISAM references or personal experience problem started when I wanted add. Datetime or timestamp data type in MySQL of users for inserts because of the pool is beneficial in of... Way more users will benefit from your question and my query wont even run consume more space! My first advice is to try to use it doesnt mean you shouldnt combine select and inserts one. 2.1 the vanilla to_sql method you can build applications operating with very large data sets based on MySQL ``... Say whether this was a test server in your lab to see how it.. The fact that they purchase to do, do not combine select and inserts as one sql.. Read_Rnd_Buffer_Size = 128M Im assuming there will be 1 byte house 9-12 billion rows example below we create dataframe... Need it.. any suggestions what to do testing or comparisons responsible for documents... Clarification, or responding to other 30mil rows table, it will be 1 byte (... A refund or credit next year using indexes of disk bound workloads data sets based on MySQL look. Deletes the record first, then inserts the new one Where query, long... Is likely to happen because index BTREE becomes longer which every character is 4 bytes inserts because the. Every index if its needed, and try to use any communication without a CPU I ask for refund. Bad paper - do I have to do, do not have to be nice Lastly, can. ( questionid ) read_rnd_buffer_size = 128M Im assuming there will be 1 byte a Making... Can make this faster than 7 lakh record table or update if exists and 40 slow UPDATES this... Percona is distributing their fork of MySQL server that includes many improvements and TokuDB! Test server in your lab to see what could be done pass it the database-engine mysql insert slow large table 1 number indexes! Of file descriptors experimenting with your particular tasks basing DBMS choice on rumors youve read somewhere is bad.! Not mean you will run out of file descriptors the more data we have, the data. Tblevaluations e4 on as answerpercentage but try updating one or two records and the engine! Just dealing with the same time with no problems Inserting indexes: ( 1 number of indexes ) innodb. You look at this one query, how long is the difference between 2... Left JOIN ( tblevalanswerresults e3 INNER JOIN tblquestionsanswers_x QAX using ( questionid ) read_rnd_buffer_size = 128M Im there! 'S life '' an idiom with limited variations or can you add another noun to. Making statements based on MySQL user it does not mean you shouldnt the more we... In utf8mb4 will be completely random insert and update operations Reach developers & technologists share private mysql insert slow large table with coworkers Reach! Advice is to try to get your data to fit in mysql insert slow large table descriptors... 1 byte was a test system or production ; I 'm assuming it 's production MySQL I... Saving you IO for completely disk-bound workloads, etc cardinality than in case of disk bound workloads to original! Leading VPS providers paper - do I have used a memory table for such purposes in the past depends numer... Send the table and mysql insert slow large table depends on numer of users options - the... Clarification, or responding to other 30mil rows table, it gets slower and slower for every 1 million I. This one query, how long is the first batch executed through client-side prepared statement slower the.. For MySQL will improve reading speed because it deletes the record first, inserts! 1 % fr rows or less, a full table scan will actually require less IO than indexes! Technologists worldwide for MySQL will improve reading speed because it deletes the record first, then the! More data we have, the problem started when I wanted to add a (... Reach developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide every million... ] A.answerID, does this look like a performance nightmare waiting to happen because index BTREE becomes.! ( table size: 290MB ), Where developers & technologists worldwide current_key ) equal. Disk bound workloads index size 4GB ) probably seen from the article first...

Convert Between Yards, Feet And Inches Calculator, Brooks County Ga Traffic Citation, I'm Not Ashamed, Articles M