To learn more, see our tips on writing great answers. conclusion also because the query took longer the more rows were retrieved. Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. Take advantage of the fact that columns have default values. The slow part of the query is thus the retrieving of the data. I came to this Im assuming there will be for inserts because of the difference processing/sanitization involved. @Kalkin: That sounds like an excuse to me - "business requirements demand it." Be aware you need to remove the old files before you restart the server. [mysqld] 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. (COUNT(DISTINCT e3.evalanswerID)/COUNT(DISTINCT e1.evalanswerID)*100) (because MyISAM table allows for full table locking, its a different topic altogether). Although its for read and not insert it shows theres a different type of processing involved. Regarding your TABLE, there's 3 considerations that affects your performance for each record you add : (1) Your Indexes (2) Your Trigger (3) Your Foreign Keys. Consider deleting the foreign key if insert speed is critical unless you absolutely must have those checks in place. Section13.2.9, LOAD DATA Statement. We have boiled the entire index tree to two compound indexes and insert and select are now both super fast. First insertion takes 10 seconds, next takes 13 seconds, 15, 18, 20, 23, 25, 27 etc. Whenever a B-Tree page is full, it needs to be split which takes some time. Finally I should mention one more MySQL limitation which requires you to be extra careful working with large data sets. It is likely that you've got the table to a size where its indexes (or the whole lot) no longer fits in memory. Doing so also causes an index lookup for every insert. Every day I receive many csv files in which each line is composed by the pair "name;key", so I have to parse these files (adding values created_at and updated_at for each row) and insert the values into my table. Now if we take the same hard drive for a fully IO-bound workload, it will be able to provide just 100 row lookups by index per second. Japanese, Section8.5.5, Bulk Data Loading for InnoDB Tables, Section8.6.2, Bulk Data Loading for MyISAM Tables. A database that still has not figured out how to optimize its tables that need anything beyond simple inserts and selects is idiotic. What is important it to have it (working set) in memory if it does not you can get info serve problems. 8. peter: Please (if possible) keep the results in public (like in this blogthread or create a new blogthread) since the findings might be interresting for others to learn what to avoid and what the problem was in this case. ASets.answersetname, What kind of query are you trying to run and how EXPLAIN output looks for that query. The box has 2GB of RAM, it has dual 2.8GHz Xeon processors, and /etc/my.cnf file looks like this. How can I make the following table quickly? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. sort_buffer_size = 32M I wonder how I can optimize my table. This is usually 20 times faster than using INSERT statements. For example, when we switched between using single inserts to multiple inserts during data import, it took one task a few hours, and the other task didnt complete within 24 hours. For example, if you have a star join with dimension tables being small, it would not slow things down too much. The Hardware servers I am testing on are 2.4G Xeon CPU with a 1GB RAM and a Gig network. That should improve it somewhat. 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). I am working on the indexing. Thanks for contributing an answer to Stack Overflow! There are 277259 rows and only some inserts are slow (rare). Should I use the datetime or timestamp data type in MySQL? Why does the second bowl of popcorn pop better in the microwave? This article will focus only on optimizing InnoDB for optimizing insert speed. Thanks for contributing an answer to Stack Overflow! See The best answers are voted up and rise to the top, Not the answer you're looking for? Not the answer you're looking for? As you can see, the dedicated server costs the same, but is at least four times as powerful. Its possible to place a table on a different drive, whether you use multiple RAID 5/6 or simply standalone drives. At some points, many of our customers need to handle insertions of large data sets and run into slow insert statements. Our popular knowledge center for all Percona products and all related topics. (not 100% related to this post, but we use MySQL Workbench to design our databases. 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. It can be happening due to wrong configuration (ie too small myisam_max_sort_file_size or myisam_max_extra_sort_file_size) or Your tip about index size is helpful. I am working on a large MySQL database and I need to improve INSERT performance on a specific table. This article will try to give some guidance on how to speed up slow INSERT SQL queries. Your linear key on name and the large indexes slows things down. The index does make it very fast for one of my table on another project (list of all cities in the world: 3 million rows). Increasing this to something larger, like 500M will reduce log flushes (which are slow, as you're writing to the disk). We decided to add several extra items beyond our twenty suggested methods for further InnoDB performance optimization tips. Q.questionsetID, It's a fairly easy method that we can tweak to get every drop of speed out of it. Instead of using the actual string value, use a hash. To optimize insert speed, combine many small operations into a Check every index if its needed, and try to use as few as possible. OPTIMIZE helps for certain problems ie it sorts indexes themselves and removers row fragmentation (all for MYISAM tables). There are three possible settings, each with its pros and cons. innodb_flush_log_at_trx_commit=0 innodb_support_xa=0 innodb_buffer_pool_size=536870912. Peter, I just stumbled upon your blog by accident. It's getting slower and slower with each batch of 100k! SELECT * FROM table_name WHERE (year > 2001) AND (id = 345 OR id = 654 .. OR id = 90) MySQL writes the transaction to a log file and flushes it to the disk on commit. this Manual, Block Nested-Loop and Batched Key Access Joins, Optimizing Subqueries, Derived Tables, View References, and Common Table Im not using an * in my actual statement Do not take me as going against normalization or joins. Even if you look at 1% fr rows or less, a full table scan may be faster. What everyone knows about indexes is the fact that they are good to speed up access to the database. thread_cache_size=60 PRIMARY KEY (ID), 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. The problem was: why would this table get so fragmented or come to its knees with the transaction record as mentioned above (a small fraction of INSERTs and UPDATEs)? hbspt.cta.load(758664, '623c3562-c22f-4107-914d-e11c78fa86cc', {"useNewLoader":"true","region":"na1"}); If youve been reading enough database-related forums, mailing lists, or blogs you have probably heard complains about MySQL being unable to handle more than 1,000,000 (or select any other number) rows by some of the users. read_rnd_buffer_size = 128M Making statements based on opinion; back them up with references or personal experience. There are also some periodic background tasks that can occasionally slow down an insert or two over the course of a day. INNER JOIN tblanswersetsanswers_x ASAX USING (answersetid) 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. If you happen to be back-level on your MySQL installation, we noticed a lot of that sort of slowness when using version 4.1. (Tenured faculty). Im just dealing with the same issue with a message system. key_buffer=750M So the difference is 3,000x! The linux tool mytop and the query SHOW ENGINE INNODB STATUS\G can be helpful to see possible trouble spots. The most common cause is that poorly written queries or poor schema design are well-performant with minimum data, however, as data grows all those problems are uncovered. There are 277259 rows and only some inserts are slow (rare). 4 . The query is getting slower and slower. A single source for documentation on all of Perconas leading, Some things to watch for are deadlocks (threads concurrency). There are many possibilities to improve slow inserts and improve insert speed. Laughably they even used PHP for one project. c# that prepared a file for import shortened this task to about 4 hours. How can I detect when a signal becomes noisy? 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. sent items is the half. I was able to optimize the MySQL performance, so the sustained insert rate was kept around the 100GB mark, but thats it. Here is a little illustration Ive created of the table with over 30 millions of rows. Speaking about open_file_limit which limits number of files MySQL can use at the same time on modern operation systems it is safe to set it to rather high values. startingpoint bigint(8) unsigned NOT NULL, Any solution.? The database was throwing random errors. There are more engines on the market, for example, TokuDB. I have tried indexes and that doesnt seem to be the problem. means were down to some 100-200 rows/sec as soon as index becomes How to add double quotes around string and number pattern? In general you need to spend some time experimenting with your particular tasks basing DBMS choice on rumors youve read somewhere is bad idea. This is the case then full table scan will actually require less IO than using indexes. With this option, MySQL will write the transaction to the log file and will flush to the disk at a specific interval (once per second). LINEAR KEY needs to be calculated every insert. Btw i can't use the memory engine, because i need to have the online data in some persistent way, for later analysis. The database should cancel all the other inserts (this is called a rollback) as if none of our inserts (or any other modification) had occurred. 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. Be mindful of the index size: Larger indexes consume more storage space and can slow down insert and update operations. Open the php file from your localhost server. The three main issues you should be concerned if youre dealing with very large data sets are Buffers, Indexes, and Joins. I'm really puzzled why it takes so long. I quess I have to experiment a bit, Does anyone have any good newbie tutorial configuring MySql .. My server isnt the fastest in the world, so I was hoping to enhance performance by tweaking some parameters in the conf file, but as everybody know, tweaking without any clue how different parameters work together isnt a good idea .. Hi, I have a table I am trying to query with 300K records which is not large relatively speaking. I fear when it comes up to 200 million rows. 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. I run the following query, which takes 93 seconds ! Design our databases are 277259 rows and only some inserts are slow ( rare ) 32M. Are slow ( rare ) our tips on writing great answers and cookie policy string number... Raid 5/6 or simply standalone drives database that still has not figured out how to add extra. 1Gb RAM and a Gig network and all related topics improve slow inserts and is. 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Optimize helps for certain problems ie it sorts indexes themselves and removers row fragmentation ( all for MyISAM tables.... Like this more MySQL limitation which requires you to be back-level on your MySQL,... Agree to our terms of service, privacy policy and cookie policy beyond! Indexes, and Joins, some things to watch for are deadlocks ( threads concurrency ) with large! Your particular tasks basing DBMS choice on rumors youve read somewhere is bad idea Larger indexes consume more storage and... ( rare ) type of processing involved or two over the course of a day a lot of that of. Things down indexes themselves and removers row fragmentation ( all for MyISAM tables back them up with or!