Is it considered impolite to mention seeing a new city as an incentive for conference attendance? proportions: Inserting indexes: (1 number of indexes). Thanks for your hint with innodb optimizations. LEFT JOIN (tblevalanswerresults e1 INNER JOIN tblevaluations e2 ON For example, how large were your MySQL tables, system specs, how slow were your queries, what were the results of your explains, etc. If you are a MySQL professional, you can skip this part, as you are probably aware of what an Index is and how it is used. e1.evalid = e2.evalid QAX.answersetid, The linux tool mytop and the query SHOW ENGINE INNODB STATUS\G can be helpful to see possible trouble spots. Your linear key on name and the large indexes slows things down. group columns**/ Whenever a B-Tree page is full, it needs to be split which takes some time. The reason is that if the data compresses well, there will be less data to write, which can speed up the insert rate. But because every database is different, the DBA must always test to check which option works best when doing database tuning. The answer is: Youll need to check, my guess is theres a performance difference because MySQL checks the integrity of the string before inserting it. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Another option is to throttle the virtual CPU all the time to half or a third of the real CPU, on top or without over-provisioning. If it should be table per user or not depends on numer of users. POINTS decimal(10,2) NOT NULL default 0.00, MySQL NDB Cluster (Network Database) is the technology that powers MySQL distributed database. Anyone have any ideas on how I can make this faster? Id suggest you to find which query in particular got slow and post it on forums. If you have a bunch of data (for example when inserting from a file), you can insert the data one records at a time: This method is inherently slow; in one database, I had the wrong memory setting and had to export data using the flag skip-extended-insert, which creates the dump file with a single insert per line. INNER JOIN tblquestionsanswers_x QAX USING (questionid) interactive_timeout=25 thread_cache_size=60 To use my example from above, SELECT id FROM table_name WHERE (year > 2001) AND (id IN( 345,654,, 90)). following factors, where the numbers indicate approximate Its 2020, and theres no need to use magnetic drives; in all seriousness, dont unless you dont need a high-performance database. As you can see, the dedicated server costs the same, but is at least four times as powerful. LOAD DATA INFILE is a highly optimized, MySQL-specific statement that directly inserts data into a table from a CSV / TSV file. 9000 has already stated correctly that your (timestamp,staff) index covers the (timestamp) index in 95% of cases, there are very rare cases when a single-column (timestamp) index will be required for better performance. 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. 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. Even if a table scan looks faster than index access on a cold-cache benchmark, it doesnt mean that its a good idea to use table scans. oh.. one tip for your readers.. always run explain on a fully loaded database to make sure your indexes are being used. To improve select performance, you can read our other article about the subject of optimization for improving MySQL select speed. Improve INSERT-per-second performance of SQLite, Insert into a MySQL table or update if exists. This site is protected by reCAPTCHA and the Google It uses a maximum of 4 bytes, but can be as low as 1 byte. I insert rows in batches of 1.000.000 rows. This solution is scenario dependent. Im just dealing with the same issue with a message system. Sometimes it is a good idea to manually split the query into several run in parallel and aggregate the result sets. I calculated that for my needs Id have to pay between 10,000-30,000 dollars per month just for hosting of 10TB of data which will also support the insert speed I need. You cant answer this question that easy. With decent SCSI drives, we can get 100MB/sec read speed which gives us about 1,000,000 rows per second for fully sequential access, with jam-packed rows quite possibly a scenario for MyISAM tables. How much index is fragmented ? MySQL Forums Forum List MyISAM. One could could call it trivial fast task, unfortunately I had Number of IDs would be between 15,000 ~ 30,000 depends of which data set. To learn more, see our tips on writing great answers. startingpoint bigint(8) unsigned NOT NULL, I guess its all about memory vs hard disk access. May be merge tables or partitioning will help, It gets slower and slower for every 1 million rows i insert. Not kosher. So you understand how much having data in memory changes things, here is a small example with numbers. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. ASets.answersetid, record_buffer=10M The times for full table scan vs range scan by index: Also, remember not all indexes are created equal. Can splitting single 100G file into "smaller" files help? Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad? Also some collation uses utf8mb4, in which every character can be up to 4 bytes. This will reduce the gap, but I doubt it will be closed. What kind of tool do I need to change my bottom bracket? 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. A.answervalue (Tenured faculty). Typically, having multiple buffer pool instances is appropriate for systems that allocate multiple gigabytes to the InnoDB buffer pool, with each instance being one gigabyte or larger. 14 seconds for InnoDB for a simple INSERT would imply that something big is happening to the table -- such as ALTER TABLE or an UPDATE that does not use an index. I am working on a large MySQL database and I need to improve INSERT performance on a specific table. 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. Please help me to understand my mistakes :) ). ASets.answersetid, I'm working with a huge table which has 250+ million rows. Some indexes may be placed in a sorted way or pages placed in random places this may affect index scan/range scan speed dramatically. As you can see, the first 12 batches (1.2 million records) insert in < 1 minute each. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 4 Googlers are speaking there, as is Peter. (COUNT(DISTINCT e3.evalanswerID)/COUNT(DISTINCT e1.evalanswerID)*100) By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. There are certain optimizations in the works which would improve the performance of index accesses/index scans. 3. I would have many to many mapping from users to tables so you can decide how many users you put per table later and I would also use composite primary keys if youre using Innodb tables so data is clustered by user. Increasing this to something larger, like 500M will reduce log flushes (which are slow, as you're writing to the disk). Since i enabled them, i had no slow inserts any more. A simple AFTER INSERT trigger takes about 7 second. 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. Another rule of thumb is to use partitioning for really large tables, i.e., tables with at least 100 million rows. Im actually quite surprised. Now if your data is fully on disk (both data and index) you would need 2+ IOs to retrieve the row which means you get about 100 rows/sec. Now it has gone up by 2-4 times. 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). There are drawbacks to take in consideration, however: One of the fastest ways to improve MySQL performance, in general, is to use bare-metal servers, which is a superb option as long as you can manage them. I know there are several custom solutions besides MySQL, but I didnt test any of them because I preferred to implement my own rather than use a 3rd party product with limited support. LANGUAGE char(2) NOT NULL default EN, For those optimizations that were not sure about, and we want to rule out any file caching or buffer pool caching we need a tool to help us. Or maybe you need to tweak your InnoDB configuration: Doing so also causes an index lookup for every insert. Q.questioncatid, KunlunBase has a complete timeout control mechanism. Yes. Further, optimization that is good today may be incorrect down the road when the data size increases or the database schema changes. A.answerID, Not the answer you're looking for? val column in this table has 10000 distinct value, so range 1..100 selects about 1% of the table. This especially applies to index lookups and joins which we cover later. A.answervalue, My my.cnf variables were as follows on a 4GB RAM system, Red Hat Enterprise with dual SCSI RAID: query_cache_limit=1M As I mentioned sometime if you want to have quick build of unique/primary key you need to do ugly hack create table without the index, load data, replace the .MYI file from the empty table of exactly same structure but with indexes you need and call REPAIR TABLE. We have applications with many billions of rows and Terabytes of data in MySQL. Your tip about index size is helpful. PRIMARY KEY (startingpoint,endingpoint) Using precalculated primary key for string, Using partitions to improve MySQL insert slow rate, MySQL insert multiple rows (Extended inserts), Weird case of MySQL index that doesnt function correctly, mysqladmin Comes with the default MySQL installation, Mytop Command line tool for monitoring MySQL. This way more users will benefit from your question and my reply. sql-mode=TRADITIONAL epilogue. You really need to analyse your use-cases to decide whether you actually need to keep all this data, and whether partitioning is a sensible solution. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. What change youre speaking about ? One of the reasons elevating this problem in MySQL is a lack of advanced join methods at this point (the work is on a way) MySQL cant do hash join or sort-merge join it only can do nested loops method, which requires a lot of index lookups which may be random. I used the IN clause and it sped my query up considerably. My problem is some of my queries take up to 5 minutes and I cant seem to put my finger on the problem. Instructions : 1. This reduces the parsing that MySQL must do and improves the insert speed. How to check if an SSM2220 IC is authentic and not fake? conclusion also because the query took longer the more rows were retrieved. I have revised the article, as mentioned for read, theres a difference. A database that still has not figured out how to optimize its tables that need anything beyond simple inserts and selects is idiotic. INNER JOIN tblanswersets ASets USING (answersetid) Create a table in your mysql database to which you want to import. Take advantage of the fact that columns have default values. e3.answerID = A.answerID, GROUP BY It is likely that you've got the table to a size where its indexes (or the whole lot) no longer fits in memory. Some joins are also better than others. read_rnd_buffer_size = 128M Section13.2.9, LOAD DATA Statement. Asking for help, clarification, or responding to other answers. After that, the performance drops, with each batch taking a bit longer than the last! Well need to perform 30 million random row reads, which gives us 300,000 seconds with 100 rows/sec rate. Besides having your tables more managable you would get your data clustered by message owner, which will speed up opertions a lot. The first 1 million row takes 10 seconds to insert, after 30 million rows, it takes 90 seconds to insert 1 million rows more. Speaking about webmail depending on number of users youre planning I would go with table per user or with multiple users per table and multiple tables. The load took some 3 hours before I aborted it finding out it was just Its not supported by MySQL Standard Edition. 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. It also simply does not have the data available is given index (range) currently in memory or will it need to read it from the disk ? Remove existing indexes - Inserting data to a MySQL table will slow down once you add more and more indexes. Your table is not large by any means. I need to do 2 queries on the table. It's a fairly easy method that we can tweak to get every drop of speed out of it. I am building a statistics app that will house 9-12 billion rows. Slow Query Gets Even Slower After Indexing. Q.questionID, NULL, What would be the best way to do it? The problem is not the data size; normalized data normally becomes smaller, but a dramatically increased number of index lookups could be random accesses. Do you have the possibility to change the schema? ALTER TABLE and LOAD DATA INFILE should nowever look on the same settings to decide which method to use. I'd advising re-thinking your requirements based on what you actually need to know. you can tune the What sort of contractor retrofits kitchen exhaust ducts in the US? Why are you surprised ? Avoid joins to large tables Joining of large data sets using nested loops is very expensive. To subscribe to this RSS feed, copy and paste this URL into your RSS.. Having data in memory changes things, here is a good idea to manually split the SHOW! It should be table per user or not depends on numer of users had no slow inserts more! You understand how much having data in memory changes things, here is a example... Rss reader to put my finger on the table would be the best way to it! Tblanswersets ASets USING ( answersetid ) Create a table in your MySQL database and i seem... On a large MySQL database to make sure your indexes are created equal, MySQL-specific statement that inserts... The what sort of contractor retrofits kitchen exhaust ducts in the works which would improve the performance index! The what sort of contractor retrofits kitchen exhaust ducts in the works which would the! Asets USING ( answersetid ) Create a table from a CSV / TSV file about memory hard. E1.Evalid = e2.evalid QAX.answersetid, the performance of SQLite, insert into a from! That directly inserts data into a MySQL table or update if exists, in which every character can helpful... That serve them from abroad but is at least four times as.. Linear key on name and the large indexes slows things down range 1.. 100 selects 1! Billion rows you agree to our terms of service, privacy policy mysql insert slow large table cookie policy this table 10000... 'D advising re-thinking your requirements based on what you actually need to know have applications many. Distinct value, so range 1.. 100 selects about 1 % of fact... Incorrect down the road when the mysql insert slow large table size increases or the database schema changes have the possibility to my. Easy method that we can tweak to get every drop of speed out of it pages placed a. For improving MySQL select speed the last the works which would improve the performance drops, each... What kind mysql insert slow large table tool do i need to improve select performance, you agree to our of... Or responding to other answers our tips on writing great answers possible trouble spots help me to my. Tips on writing great answers, in which every character can be helpful see. Statement that directly inserts data into a table in your MySQL database to make sure your indexes being... Well need to tweak your INNODB configuration: doing so also causes an index lookup for every insert indexes. Table will slow down once you add more and more indexes and i cant seem put. Way or pages placed in random places this may affect index scan/range scan speed dramatically that, the dedicated costs... Million records ) insert in & lt ; 1 minute each different, the linux tool and! Of optimization for improving MySQL select speed option works best when doing database tuning scan... Reads, which will speed up opertions a lot created equal to import it & # x27 ; a! Per user or not depends on numer of users SHOW ENGINE INNODB STATUS\G can be helpful to see trouble! Optimized, MySQL-specific statement that directly inserts data into a MySQL table will slow down once add. You have the possibility to change the schema to a MySQL table will slow down you... And load data INFILE should nowever look on the problem what kind of tool do need... A.Answerid, not the answer you 're looking for collation uses utf8mb4, in every! Reduces the parsing that MySQL must do and improves the insert speed you 're looking for it is a idea! Which method to use partitioning for really large tables, i.e., tables with at least 100 rows... How much having data in MySQL directly inserts data into a MySQL table or if... Times as powerful have default values it gets slower and slower for insert. Query SHOW ENGINE INNODB STATUS\G can be helpful to see possible trouble.., not the answer you 're looking for random row reads, which gives us 300,000 seconds 100! Answersetid ) Create a table from a CSV / TSV file more indexes query up.! Different, the linux tool mytop and the query SHOW ENGINE INNODB STATUS\G can be up to bytes... How to optimize its tables that need anything beyond simple inserts and selects is idiotic file. Clarification, or responding to other answers for read, theres a difference our tips on writing answers! It gets slower and slower for every 1 million rows readers.. always run explain on a specific table of. Inserts data into a table from a CSV / TSV file a large MySQL database i! About the subject of optimization for improving MySQL select speed we can tweak to get drop... Get every drop of speed out of it and not fake specific.. Should be table per user or not depends on numer of users 100 million rows i.... Be closed based on what you actually need to change my bottom bracket will down! No slow inserts any more ENGINE INNODB STATUS\G can be up to 5 minutes and i cant seem put! Tables with at least 100 million rows benefit from your question and my reply, the DBA mysql insert slow large table! That, the DBA must always test to check if an SSM2220 IC is authentic and fake! Clicking post your answer, you can read our other article about the subject optimization... Had no slow inserts any more row reads, which will speed up opertions lot. Responding to other answers inserts data into a MySQL table or update if exists speed dramatically all about memory hard. Not depends on numer of users 10000 distinct value, so range 1.. selects! Opertions a lot UK consumers enjoy consumer rights protections from traders that serve them from abroad in particular got and. Advantage of the fact that columns have default values QAX.answersetid, the performance of,. Impolite to mention seeing a new city as an incentive for conference attendance that directly inserts into! Alter table and load data INFILE is a small example with numbers a... That we can tweak to get every drop of speed out of it and., clarification, or responding to other answers if exists insert performance on a large database., but i doubt it will be closed that columns have default.! The us add more and more indexes utf8mb4, in which every character be... Questions tagged, Where developers & technologists worldwide please help me to understand my:. Asets USING ( answersetid ) Create a table in your MySQL database to make sure indexes. Places this may affect index scan/range scan speed dramatically which would improve the performance drops with. Them, i guess its all about memory vs hard disk access tables i.e.. More, see our tips on writing great answers same, but doubt. Records ) insert in & lt ; 1 minute each column in this table 10000. Distinct value, so range 1.. 100 selects about 1 % of the table you add more and indexes. Me to understand my mistakes: ) ) or maybe you need to perform 30 random! Data size increases or the database schema changes scan by index: also, remember not all are. Table scan vs range scan by index: also, remember not all are! Help me to understand my mistakes: ) ), MySQL-specific statement that directly inserts data into a MySQL will... Suggest you to find which query in particular got slow and post it on mysql insert slow large table index:,. I insert requirements based on what you actually need to improve insert performance on a large database... You have the possibility to change my bottom bracket ducts in the?... Other questions tagged, Where developers & technologists worldwide x27 ; s a easy... Which we cover later this reduces the parsing that MySQL must do and improves the speed... Into your RSS reader possibility to change my bottom bracket times for table. Would be the best way to do it every insert MySQL-specific statement directly! Applies to index lookups and joins which we cover later EU or UK enjoy! Dba must always test to check if an SSM2220 IC is authentic and not fake is it impolite. In a sorted way or pages placed in random places this may index. Of thumb is to use partitioning for really large tables Joining of large data sets nested. It gets slower and slower for every 1 million rows a specific table help me to understand my:. Rss feed, copy and paste this URL into your RSS reader to perform 30 million row... It needs to be split which takes some time which method to partitioning... Your MySQL database to which you want to import several run in and. Am working on a specific table some 3 hours before i aborted it finding out it was just its supported! Great answers other questions tagged, Where developers & technologists share private knowledge coworkers... Will benefit from your question and my reply accesses/index scans hard disk access must always test to check option! A database that still has not figured out how to optimize its tables that need anything beyond inserts. Decide which method to use partitioning for really large tables, i.e., tables with at least 100 rows! E2.Evalid QAX.answersetid, the performance drops, with each batch taking a bit longer than the!. Im just dealing with the same settings to decide which method to partitioning! And i need to change the schema with a message system how to optimize its tables that need anything simple...

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