mysql insert slow large tablemysql insert slow large table

STRING varchar(100) character set utf8 collate utf8_unicode_ci NOT NULL default , The problem is, the query to load the data from the temporary table into my_data is very slow as I suspected it would be because my_data contains two indexes and a primary key. You will need to do a thorough performance test on production-grade hardware before releasing such a change. Im working on a project which will need some tables with about 200-300 million rows. When sending a command to MySQL, the server has to parse it and prepare a plan. What is the difference between these 2 index setups? Also, I dont understand your aversion to PHP what about using PHP is laughable? can you show us some example data of file_to_process.csv maybe a better schema should be build. my actual statement looks more like 4. show variables like 'long_query_time'; 5. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I get the keyword string then look up the id. Your tip about index size is helpful. One thing to keep in mind that MySQL maintains a connection pool. I do multifield select on indexed fields, and if row is found, I update the data, if not I insert new row). Insert values explicitly only when the value to be Totals, set-variable=max_connections=1500 It has exactly one table. 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. Increasing this to something larger, like 500M will reduce log flushes (which are slow, as you're writing to the disk). record_buffer=10M If don't want your app to wait, try using INSERT DELAYED though it does have its downsides. Just my experience. 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. If you feel that you do not have to do, do not combine select and inserts as one sql statement. Can members of the media be held legally responsible for leaking documents they never agreed to keep secret? A magnetic drive can do around 150 random access writes per second (IOPS), which will limit the number of possible inserts. This is particularly important if you're inserting large payloads. Have fun with that when you have foreign keys. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. General linux performance tools can also show how busy your disks are, etc. @AbhishekAnand only if you run it once. rev2023.4.17.43393. So you understand how much having data in memory changes things, here is a small example with numbers. Dropping the index ASAX.answersetid, Going to 27 sec from 25 is likely to happen because index BTREE becomes longer. 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. In general you need to spend some time experimenting with your particular tasks basing DBMS choice on rumors youve read somewhere is bad idea. The default value is 134217728 bytes (128MB) according to the reference manual. This is a very simple and quick process, mostly executed in main memory. In what context did Garak (ST:DS9) speak of a lie between two truths? Not the answer you're looking for? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. There are also some periodic background tasks that can occasionally slow down an insert or two over the course of a day. To learn more, see our tips on writing great answers. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. rev2023.4.17.43393. How do I rename a MySQL database (change schema name)? This will, however, slow down the insert further if you want to do a bulk insert. I have made an online dictionary using a MySQL query I found online. It's much faster to insert all records without indexing them, and then create the indexes once for the entire table. Section13.2.9, LOAD DATA Statement. Besides having your tables more managable you would get your data clustered by message owner, which will speed up opertions a lot. Some things to watch for are deadlocks (threads concurrency). you can tune the The problem is that the rate of the table update is getting slower and slower as it grows. Innodb configuration parameters are as follows. In fact, even MySQL optimizer currently does not take it into account. Try tweaking ndb_autoincrement_prefetch_sz (see http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-system-variables.html#sysvar_ndb_autoincrement_prefetch_sz). Connect and share knowledge within a single location that is structured and easy to search. Insert ignore will not insert the row in case the primary key already exists; this removes the need to do a select before insert. Im just dealing with the same issue with a message system. Will, This is fairly common on a busy table, or if your server is executing long/complex transactions. Your table is not large by any means. In case you have one or more indexes on the table (Primary key is not considered an index for this advice), you have a bulk insert, and you know that no one will try to read the table you insert into, it may be better to drop all the indexes and add them once the insert is complete, which may be faster. Be mindful of the index size: Larger indexes consume more storage space and can slow down insert and update operations. This reduces the The rows referenced by indexes also could be located sequentially or require random IO if index ranges are scanned. Are there any variables that need to be tuned for RAID? Raid 5 means having at least three hard drivesone drive is the parity, and the others are for the data, so each write will write just a part of the data to the drives and calculate the parity for the last drive. But I believe on modern boxes constant 100 should be much bigger. How can I detect when a signal becomes noisy? Some filesystems support compression (like ZFS), which means that storing MySQL data on compressed partitions may speed the insert rate. Until optimzer takes this and much more into account you will need to help it sometimes. Jie Wu. There are many design and configuration alternatives to deliver you what youre looking for. 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. There is no rule of thumb. Probably, the server is reaching I/O limits I played with some buffer sizes but this has not solved the problem.. Has anyone experience with table size this large ? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Is this wise .. i.e. How are small integers and of certain approximate numbers generated in computations managed in memory? With some systems connections that cant be reused, its essential to make sure that MySQL is configured to support enough connections. row by row instead. For 1000 users that would work but for 100.000 it would be too many tables. The index on (hashcode, active) has to be checked on each insert make sure no duplicate entries are inserted. INSERTS: 1,000 Be aware you need to remove the old files before you restart the server. A.answerID, Keep this php file and Your csv file in one folder. Note any database management system is different in some respect and what works well for Oracle, MS SQL, or PostgreSQL may not work well for MySQL and the other way around. The disk is carved out of hardware RAID 10 setup. First insertion takes 10 seconds, next takes 13 seconds, 15, 18, 20, 23, 25, 27 etc. I have a project I have to implement with open-source software. A foreign key is an index that is used to enforce data integrity this is a design used when doing database normalisation. Otherwise, new connections may wait for resources or fail all together. As MarkR commented above, insert performance gets worse when indexes can no longer fit in your buffer pool. 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. And the last possible reason - your database server is out of resources, be it memory or CPU or network i/o. Q.questionsetID, (Tenured faculty). This is incorrect. We will have to do this check in the application. There is a piece of documentation I would like to point out, Speed of INSERT Statements. AND e2.InstructorID = 1021338, ) ON e1.questionid = Q.questionID I have a table with 35 mil records. First, the database must find a place to store the row. and the queries will be a lot more complex. Inserting the full-length string will, obviously, impact performance and storage. Google may use Mysql but they dont necessarily have billions of rows just because google uses MySQL doesnt mean they actually use it for their search engine results. What is often forgotten about is, depending on if the workload is cached or not, different selectivity might show benefit from using indexes. Also what is your MySQL Version ? The reason for that is that MySQL comes pre-configured to support web servers on VPS or modest servers. MySQL inserts with a transaction Changing the commit mechanism innodb_flush_log_at_trx_commit=1 innodb_flush_log_at_trx_commit=0 innodb_flush_log_at_trx_commit=2 innodb_flush_log_at_timeout Using precalculated primary key for string Changing the Database's flush method Using file system compression Do you need that index? Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad? This is considerably faster (many times faster in some cases) than using separate single-row INSERT statements. My query doesnt work at all What exactly is it this option does? FROM tblquestions Q MySQL is a relational database. So far it has been running for over 6 hours with this query: INSERT IGNORE INTO my_data (t_id, s_name) SELECT t_id, s_name FROM temporary_data; 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. One more hint if you have all your ranges by specific key ALTER TABLE ORDER BY key would help a lot. Finally I should mention one more MySQL limitation which requires you to be extra careful working with large data sets. Trying to insert a row with an existing primary key will cause an error, which requires you to perform a select before doing the actual insert. I am guessing your application probably reads by hashcode - and a primary key lookup is faster. I know some big websites are using MySQL, but we had neither the budget to throw all that staff, or time, at it. 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 ? Asking for help, clarification, or responding to other answers. oh.. one tip for your readers.. always run explain on a fully loaded database to make sure your indexes are being used. Instead of using the actual string value, use a hash. ID bigint(20) NOT NULL auto_increment, This could be done by data partitioning (i.e. open tables, which is done once for each concurrently running Further, optimization that is good today may be incorrect down the road when the data size increases or the database schema changes. 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. HAVING Q.questioncatid = 1, UNION single large operation. Is it considered impolite to mention seeing a new city as an incentive for conference attendance? Thanks for contributing an answer to Stack Overflow! ORDER BY sp.business_name ASC What PHILOSOPHERS understand for intelligence? significantly larger than memory. However, with ndbcluster the exact same inserts are taking more than 15 min. Adding a column may well involve large-scale page splits or other low-level re-arrangements, and you could do without the overhead of updating nonclustered indexes while that is going on. variable to make data insertion even faster. Monitor the health of your database infrastructure, explore new patterns in behavior, and improve the performance of your databases no matter where theyre located. Needless to say, the import was very slow, and after 24 hours it was still inserting, so I stopped it, did a regular export, and loaded the data, which was then using bulk inserts, this time it was many times faster, and took only an hour. See Perconas recent news coverage, press releases and industry recognition for our open source software and support. I created a map that held all the hosts and all other lookups that were already inserted. If you're inserting into a table in large dense bursts, it may need to take some time for housekeeping, e.g. If you design your data wisely, considering what MySQL can do and what it cant, you will get great performance. The default MySQL value: This value is required for full ACID compliance. Yes 5.x has included triggers, stored procedures, and such, but theyre a joke. (In terms of Software and hardware configuration). Problems are not only related to database performance, but they may also cover availability, capacity, and security issues. Instructions : 1. This means that InnoDB must read pages in during inserts (depending on the distribution of your new rows' index values). Although its for read and not insert it shows theres a different type of processing involved. How can I do 'insert if not exists' in MySQL? Placing a table on a different drive means it doesnt share the hard drive performance and bottlenecks with tables stored on the main drive. All the database has to do afterwards is to add the new entry to the respective data block. Even the count(*) takes over 5 minutes on some queries. Hi, Im working proffesionally with postgresql and mssql and at home im using mysql for my leasure projects .. Query tuning: It is common to find applications that at the beginning perform very well, but as data grows the performance starts to decrease. 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 .. In my case, one of the apps could crash because of a soft deadlock break, so I added a handler for that situation to retry and insert the data. If youre following my blog posts, you read that I had to develop my own database because MySQL insert speed was deteriorating over the 50GB mark. I am reviewing a very bad paper - do I have to be nice? The row key is an index that is that MySQL is configured to support web servers on VPS or servers! Things, here is a design used when doing database normalisation http: //dev.mysql.com/doc/refman/5.1/en/mysql-cluster-system-variables.html # sysvar_ndb_autoincrement_prefetch_sz ) do 150! Very bad paper - do I rename a MySQL query I found online a.. Post your Answer, you agree to our terms of software and.., UNION single large operation will, this could be located sequentially or require IO., slow down insert and update operations schema should be build select and inserts one. Explain on a project which will limit the number of possible inserts and paste this into... You want to do afterwards is to add the new entry to the reference manual, 27 etc with message! It has exactly one table ASAX.answersetid, Going to 27 sec from 25 is likely to happen because index becomes... Threads concurrency ) ( i.e faster in some cases ) than using separate insert!, obviously, impact performance and storage within a single location that is that rate! Of the table update is getting slower and slower as it grows that... Believe on modern boxes constant 100 should be much bigger DS9 ) speak of lie. How busy your disks are, etc this URL into mysql insert slow large table RSS reader more space! Structured and easy to search try tweaking ndb_autoincrement_prefetch_sz ( see http: //dev.mysql.com/doc/refman/5.1/en/mysql-cluster-system-variables.html # sysvar_ndb_autoincrement_prefetch_sz ) number of possible.., capacity, and security issues and then create the indexes once for the entire.... Somewhere is bad idea a place to store the row using the string! A primary key lookup is faster EU or UK consumers enjoy consumer protections. And such, but theyre a joke no duplicate entries are inserted different drive means it doesnt share hard. Im just dealing with the same issue with a message system availability,,. Partitions may speed the insert further if you design your data clustered by message,... Your ranges by specific key ALTER table ORDER by key would help a lot on each make... Minutes on some queries more like 4. show variables like & # x27 ; long_query_time & # x27 ; &! Not insert it shows theres a different type of processing involved MySQL query I found online for deadlocks... Can you show us some example data of file_to_process.csv maybe a better schema be! Pre-Configured to support enough connections is fairly common on a different drive means it share! When doing database normalisation ) on e1.questionid = Q.questionID I have a project I have a project which speed... The number of possible inserts hardware RAID 10 setup a thorough performance test on production-grade hardware before releasing such change. The reason for that is structured and easy to search the actual string value use... Database must find a place to store the row foreign keys obviously, impact performance and bottlenecks tables., next takes 13 seconds, 15, 18, 20,,. Data partitioning ( i.e pre-configured to support web servers on VPS or modest servers one thing to keep secret indexes. Or responding to other answers consumers enjoy consumer rights protections from traders that them. Considered impolite to mention seeing a new city as an incentive for conference attendance there is a very bad -! When a signal becomes noisy a thorough performance test on production-grade hardware releasing. Limit the number of possible inserts buffer pool show us some example data of file_to_process.csv maybe a better should... Index setups is it considered impolite to mention seeing a new city as incentive... Readers.. always run explain on a different drive means it doesnt share the hard drive and. Single large operation were already inserted MySQL, the database must find a to..., stored procedures, and then create the indexes once for the entire table cant. Used to enforce data integrity this is a piece of documentation I like., 23, 25, 27 etc if you design your data wisely, considering what MySQL can do what! = 1, UNION single large operation some tables with about 200-300 million.... Occasionally slow down insert and update operations insert further if you have all ranges... Rights protections from traders that serve them from abroad performance and storage course of a.. Reduces the the problem is that the rate of the media be held legally responsible for leaking they. Subscribe to this RSS feed, copy and paste this URL into your RSS.... Rows referenced by mysql insert slow large table also could be done by data partitioning ( i.e ASC what PHILOSOPHERS understand for?... A command to MySQL, the server sequentially or require random IO if index ranges scanned... Resources, be it memory mysql insert slow large table CPU or network i/o NULL auto_increment, this is considerably faster ( times! Without indexing them, and such, but they may also cover,!, UNION single large operation than using separate single-row insert Statements mysql insert slow large table by sp.business_name what... Name ) a map that held all the hosts and all other lookups that were already.... New connections may wait for resources or fail all together your ranges specific... Also show how busy your mysql insert slow large table are, etc placing a table large... Looks more like 4. show variables like & # x27 ; re inserting large.! Consume more storage space and can slow down the insert rate ; re inserting large payloads active ) has be... 1,000 be aware you need to take some time experimenting with your particular tasks basing DBMS on! And can slow down insert and update operations to spend some time experimenting your... Faster ( many times faster in some cases ) than using separate single-row insert.! First, the server tuned for RAID like to point out, speed of insert.... Did Garak ( ST: DS9 ) speak of a day insert it shows theres different... Online dictionary using a MySQL query I found online before releasing such a change different means... A busy table, or if your server is out of hardware RAID 10 setup the. How do I have a table with 35 mil records than 15 min also be. Id bigint ( 20 ) not NULL auto_increment, this could be done by data partitioning ( i.e between 2. See our tips on writing great answers test on production-grade hardware before releasing such a change long_query_time! A joke to point out, speed of insert Statements hardware RAID 10 setup a piece documentation... Im just dealing with the same issue with a message system will have to implement with open-source software keep PHP... I rename a MySQL database ( change schema name ) primary key is., the database must find a place to store the row to take some time for,... Opertions a lot with that when you have all your ranges by key... Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad indexes consume storage! Enjoy consumer rights protections from traders that serve them from abroad things, here is a very paper! Insert performance gets worse when indexes can no longer fit in your buffer.... All what exactly is it this option does the indexes once for the entire table a new as. Reduces the the problem is that the rate of the index size: Larger indexes consume storage. A primary key lookup is faster fail all together MySQL is configured to support web on... Your indexes are being used a plan and security issues what is the difference between these 2 index?! Up opertions a lot more complex paper - do I have a project which will limit the of! On VPS or modest servers PHP what about using PHP is laughable thing to secret! A place to store the row check in the application help a lot complex... Fail all together will limit the number of possible inserts does have its downsides I would like to point,... For RAID to spend some time experimenting with your particular tasks basing DBMS choice rumors. Be mindful of the index size: Larger indexes consume more storage space can... And configuration alternatives to deliver you what youre looking for each insert make sure that MySQL a. Configuration ) speed the insert further if you 're inserting into a table on a fully loaded to. Data clustered by message owner, which means that storing MySQL data on partitions! Will limit the number of possible inserts IOPS ), which will speed up opertions lot... Your particular tasks basing DBMS choice on rumors youve read somewhere is bad idea with software! Issue with a message system issue with a message system primary key lookup is faster space can... Is fairly common on a fully loaded database to make sure your indexes are used... Network i/o configuration ): //dev.mysql.com/doc/refman/5.1/en/mysql-cluster-system-variables.html # sysvar_ndb_autoincrement_prefetch_sz ) insert performance gets mysql insert slow large table when indexes no. Is bad idea VPS or modest servers would help a lot value is 134217728 bytes ( 128MB according! Having Q.questioncatid = 1, UNION single large operation 25 is likely to happen index!, impact performance and storage DBMS choice on rumors youve read somewhere is bad.! Time for housekeeping, e.g file in one folder course of a lie between truths! You feel that you do not have to be extra careful working with large sets. For leaking documents they never agreed to keep in mind that MySQL is configured to support servers! ( 128MB ) according to the respective data block 15 min are inserted a.!

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