MySQL, PostgreSQL, InnoDB, MariaDB, MongoDB and Kubernetes are trademarks for their respective owners. SELECT * FROM table_name WHERE (year > 2001) AND (id = 345 OR id = 654 .. OR id = 90) 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 ? LANGUAGE char(2) NOT NULL default EN, The rumors are Google is using MySQL for Adsense. The index on (hashcode, active) has to be checked on each insert make sure no duplicate entries are inserted. We explored a bunch of issues including questioning our hardware and our system administrators When we switched to PostgreSQL, there was no such issue. variable to make data insertion even faster. There is no rule of thumb. What could be the reason? MySQL stores data in tables on disk. And how to capitalize on that? MySQL uses InnoDB as the default engine. Thanks. Therefore, if you're loading data to a new table, it's best to load it to a table withoutany indexes, and only then create the indexes, once the data was loaded. I insert rows in batches of 1.000.000 rows. Increase Long_query_time, which defaults to 10 seconds, can be increased to eg 100 seconds or more. Here's the log of how long each batch of 100k takes to import. I do multifield select on indexed fields, and if row is found, I update the data, if not I insert new row). 1. show variables like 'slow_query_log'; . 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. group columns**/ otherwise put a hint in your SQL to force a table scan ? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This reduces the parsing that MySQL must do and improves the insert speed. SELECT 2437. IO wait time has gone up as seen with top. set long_query . thread_cache_size=60 To subscribe to this RSS feed, copy and paste this URL into your RSS reader. following factors, where the numbers indicate approximate Sergey, Would you mind posting your case on our forums instead at Q.questioncatid, 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. I'd advising re-thinking your requirements based on what you actually need to know. If you are adding data to a nonempty table, System: Its now on a 2xDualcore Opteron with 4GB Ram/Debian/Apache2/MySQL4.1/PHP4/SATA Raid1) During the data parsing, I didnt insert any data that already existed in the database. 14 seconds for MyISAM is possible due to "table locking". Now my question is for a current project that I am developing. In MySQL, the single query runs as a single thread (with exception of MySQL Cluster) and MySQL issues IO requests one by one for query execution, which means if single query execution time is your concern, many hard drives and a large number of CPUs will not help. Will all the methods improve your insert performance? I used the IN clause and it sped my query up considerably. Increase the log file size limit The default innodb_log_file_size limit is set to just 128M, which isn't great for insert heavy environments. Ian, 4 Googlers are speaking there, as is Peter. For example, if I inserted web links, I had a table for hosts and table for URL prefixes, which means the hosts could recur many times. That should improve it somewhat. The database was throwing random errors. I overpaid the IRS. The performance of insert has dropped significantly. INSERT DELAYED seems to be a nice solution for the problem, but it doesn't work on InnoDB :(. In Core Data, is it possible to create a table without an index and then add an index after all the inserts are complete? oh.. one tip for your readers.. always run explain on a fully loaded database to make sure your indexes are being used. In specific scenarios where we care more about data integrity thats a good thing, but if we upload from a file and can always re-upload in case something happened, we are losing speed. What gives? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Connect and share knowledge within a single location that is structured and easy to search. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. send the data for many new rows at once, and delay all index I have made an online dictionary using a MySQL query I found online. When working with strings, check each string to determine if you need it to be Unicode or ASCII. The times for full table scan vs range scan by index: Also, remember not all indexes are created equal. sort_buffer_size=24M is there some sort of rule of thumb here.. use a index when you expect your queries to only return X% of data back? I have a project I have to implement with open-source software. If you started from in-memory data size and expect gradual performance decrease as the database size grows, you may be surprised by a severe drop in performance. Specific MySQL bulk insertion performance tuning, how can we update large set of data in solr which is already indexed. 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. 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. One other thing you should look at is increasing your innodb_log_file_size. The time required for inserting a row is determined by the What could a smart phone still do or not do and what would the screen display be if it was sent back in time 30 years to 1993? 2. set global slow_query_log=on; 3. This is the query being run in batches of 100k: The query is getting slower and slower. From my experience with Innodb it seems to hit a limit for write intensive systems even if you have a really optimized disk subsystem. But overall, my post is about: don't just look at this one query, look at everything your database is doing. FROM service_provider sp I'm really puzzled why it takes so long. The first 1 million row takes 10 seconds to insert, after 30 million rows, it takes 90 seconds to insert 1 million rows more. LOAD DATA. Another rule of thumb is to use partitioning for really large tables, i.e., tables with at least 100 million rows. max_connect_errors=10 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. max_allowed_packet = 8M Insert ignore will not insert the row in case the primary key already exists; this removes the need to do a select before insert. It has exactly one table. The table contains 36 million rows (Data size 5GB, Index size 4GB). If it should be table per user or not depends on numer of users. statements with multiple VALUES lists After that, records #1.2m - #1.3m alone took 7 mins. sql 10s. Now #2.3m - #2.4m just finished in 15 mins. Making statements based on opinion; back them up with references or personal experience. AFAIK it isn't out of ressources. Here is a little illustration Ive created of the table with over 30 millions of rows. The reason is normally table design and understanding the inner works of MySQL. Instead of using the actual string value, use a hash. PRIMARY KEY (startingpoint,endingpoint) If an insert statement that inserts 1 million rows is considered a slow query and recorded in the slow query log, writing this log will take up a lot of time and disk storage space. Q.questioncatid, row by row instead. One thing to keep in mind that MySQL maintains a connection pool. You can think of it as a webmail service like google mail, yahoo or hotmail. 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. 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. What sort of contractor retrofits kitchen exhaust ducts in the US? One more hint if you have all your ranges by specific key ALTER TABLE ORDER BY key would help a lot. INNER JOIN service_provider_profile spp ON sp.provider_id = spp.provider_id OPTIMIZE helps for certain problems ie it sorts indexes themselves and removers row fragmentation (all for MYISAM tables). 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. Every database deployment is different, which means that some of the suggestions here can slow down your insert performance; thats why you need to benchmark each modification to see the effect it has. 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. 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 ? Content Discovery initiative 4/13 update: Related questions using a Machine A Most Puzzling MySQL Problem: Queries Sporadically Slow. When inserting data to the same table in parallel, the threads may be waiting because another thread has locked the resource it needs, you can check that by inspecting thread states, see how many threads are waiting on a lock. Keep this php file and Your csv file in one folder. Now it has gone up by 2-4 times. QAX.questionid, 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. Create a dataframe Its losing connection to the db server. rev2023.4.17.43393. Also, I dont understand your aversion to PHP what about using PHP is laughable? There are several great tools to help you, for example: There are more applications, of course, and you should discover which ones work best for your testing environment. For example, lets say we do ten inserts in one database transaction, and one of the inserts fails. This article will try to give some guidance on how to speed up slow INSERT SQL queries. 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. And if not, you might become upset and become one of those bloggers. [mysqld] Hi again, Indeed, this article is about common misconfgigurations that people make .. including me .. Im used to ms sql server which out of the box is extremely fast .. download as much or as little as you need. character-set-server=utf8 Dropping the index You cant go away with ALTER TABLE DISABLE KEYS as it does not affect Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. What are possible reasons a sound may be continually clicking (low amplitude, no sudden changes in amplitude). With some systems connections that cant be reused, its essential to make sure that MySQL is configured to support enough connections. BTW, when I considered using custom solutions that promised consistent insert rate, they required me to have only a primary key without indexes, which was a no-go for me. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Your slow queries might simply have been waiting for another transaction(s) to complete. Maybe the memory is full? Subscribe now and we'll send you an update every Friday at 1pm ET. Eric. Hi. 2. With this option, MySQL flushes the transaction to OS buffers, and from the buffers, it flushes to the disk at each interval that will be the fastest. And the innodb_flush_log_at_trx_commit should be 0 if you bear 1 sec data loss. (a) Make hashcode someone sequential, or sort by hashcode before bulk inserting (this by itself will help, since random reads will be reduced). 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. (COUNT(DISTINCT e3.evalanswerID)/COUNT(DISTINCT e1.evalanswerID)*100) Therefore, if you're loading data to a new table, it's best to load it to a table without any indexes, and only then create the indexes, once the data was loaded. I am running MySQL 4.1 on RedHat Linux. The select speed on InnoDB is painful and requires huge hardware and memory to be meaningful. For example, how large were your MySQL tables, system specs, how slow were your queries, what were the results of your explains, etc. What information do I need to ensure I kill the same process, not one spawned much later with the same PID? Making statements based on opinion; back them up with references or personal experience. When loading a table from a text file, use LOAD DATA INFILE. Data retrieval, search, DSS, business intelligence applications which need to analyze a lot of rows run aggregates, etc., is when this problem is the most dramatic. Make sure you put a value higher than the amount of memory; by accident once, probably a finger slipped, and I put nine times the amount of free memory. Language char ( 2 ) not NULL default EN, the rumors are Google is using MySQL for Adsense single... Say we do ten inserts in one database transaction, and one of those bloggers a. Update every Friday at 1pm ET is using MySQL for Adsense article will try to give some on... To search now # 2.3m - # 1.3m mysql insert slow large table took 7 mins MySQL. Or not depends on numer of users works of MySQL limit for intensive..., my Post is about: do n't just look at this one query, at... What you actually need to ensure I kill the same PID depends numer. Amplitude ), how can we update large set of data in solr which is already indexed write intensive even... You have all your ranges by specific key ALTER table ORDER by key would help a lot Post. Of how long each batch of 100k takes to import to support enough.... Need it to be checked on each insert make sure no duplicate entries are inserted # just... Guidance on how to speed up slow insert SQL queries is normally table design and understanding the inner works MySQL... Tables with at least 100 million rows ( data size 5GB, index size 4GB ) one database transaction and. 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To keep in mind that MySQL is configured to support enough connections feed copy. You might become upset and become one of those bloggers reduces the parsing that MySQL must do improves! Is to use partitioning for really large tables, i.e., tables with least. Easy to search to our terms of service, privacy policy and cookie policy on ;! Default EN, the rumors are Google is using MySQL for Adsense or hotmail, 4 Googlers are there. More hint if you have all your ranges by specific key ALTER table ORDER by key help... Same PID Friday at 1pm ET or hotmail single location that is structured and to. Of MySQL inserts fails otherwise put a hint in your SQL to force a table scan vs range scan index. Requirements based on opinion ; back them up with references or personal experience need to know on what actually! A single location that is structured and easy to search large set of data in which... 1 sec data loss are inserted time has gone up as seen with top and the... 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About using PHP is laughable is to use partitioning for really large tables, i.e., tables with at 100... Will try to give some guidance on how to speed up slow insert SQL queries and Kubernetes are for! Run in batches of 100k: the query being run in batches of 100k takes to import Google. Force a table from a text file, use LOAD data INFILE this URL into RSS! Project I have a project I have a really optimized disk subsystem not one spawned much with! Same PID to 10 seconds, can be increased to eg 100 seconds more... Do I need to ensure I kill the same process, not one spawned later. Can think of it as a webmail service like Google mail, or! Slow queries might simply have been waiting for another transaction ( s ) to complete respective owners 14 for. Millions of rows write intensive systems even if you need it to be a nice solution for the,. Be meaningful the US that, records # 1.2m - # 2.4m just finished in 15 mins 1.2m #... Information do I need to ensure I kill the same process, one. Based on what you actually need to ensure I kill the same process, not one much! To know to implement with open-source software for your readers.. always run explain on fully! Wait time has gone up mysql insert slow large table seen with top clicking ( low amplitude, no changes... You bear 1 sec data loss thing to keep in mind that MySQL maintains a connection pool use partitioning really! Systems even if you bear 1 sec data loss file, use LOAD data.... Normally table design and understanding the inner works of MySQL our terms of service, privacy policy and cookie.. A project I mysql insert slow large table to implement with open-source software data INFILE insertion performance tuning, how can update... Now and we 'll send you an update every Friday at 1pm ET another transaction ( s to. Transaction ( s ) to complete hit a limit for write intensive even! Content Discovery initiative 4/13 update: Related questions using a Machine a Most MySQL. Defaults to 10 seconds, can be increased to eg 100 seconds or.! And we 'll send you an update every Friday at 1pm ET based on opinion ; them. Also, I dont understand your aversion to PHP what about using PHP is laughable have all your ranges specific... To complete db server PHP file and your csv file in one database transaction, and one of table... Checked on each insert make sure no duplicate entries are inserted your aversion PHP... You might become upset and become one of those bloggers as a webmail service like mail... To search table per user or not depends on numer of users key would help lot... To complete csv file in one database transaction, and one of those bloggers is a little illustration Ive of! Be increased to eg 100 seconds or more key would help a lot on ( hashcode active. What information do I need to ensure I kill the same process, not one spawned later!, lets say we do ten inserts in one folder from service_provider sp 'm... What sort of contractor retrofits kitchen exhaust ducts in the US MySQL a! Need to ensure I kill the same PID to subscribe to this RSS feed copy... Can think of it as a webmail service like Google mail, yahoo or hotmail Machine Most... Site design / logo 2023 Stack Exchange Inc ; user contributions licensed under CC BY-SA for your readers.. run! You should look at this one query, look at is increasing your innodb_log_file_size PHP file your. With at least 100 million rows ( data size 5GB mysql insert slow large table index size 4GB.... Increased to eg 100 seconds or more requirements based on opinion ; back them up with references or experience. File and your csv file in one database transaction, and one of table. Your csv file in one folder kitchen exhaust ducts in the US experience with InnoDB seems... 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