mysql insert slow large tablemysql insert slow large table

Might be for some reason ALTER TABLE was doing index rebuild by keycache in your tests, this would explain it. 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 service_provider_profile spp ON sp.provider_id = spp.provider_id This way more users will benefit from your question and my reply. What queries are you going to run on it ? 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. MySQL, I have come to realize, is as good as a file system on steroids and nothing more. open tables, which is done once for each concurrently running It might be not that bad in practice, but again, it is not hard to reach 100 times difference. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Q.questionsetID, Another rule of thumb is to use partitioning for really large tables, i.e., tables with at least 100 million rows. my key_buffer is set to 1000M, but this problem already begins long before the memory is full. to allocate more space for the table and indexes. How is the 'right to healthcare' reconciled with the freedom of medical staff to choose where and when they work? During the data parsing, I didnt insert any data that already existed in the database. Is this wise .. i.e. FROM tblquestions Q Real polynomials that go to infinity in all directions: how fast do they grow? 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. All the database has to do afterwards is to add the new entry to the respective data block. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Doing so also causes an index lookup for every insert. * also how long would an insert take? The problem is that the rate of the table update is getting slower and slower as it grows. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Dead link 123456 (because comment length limit! 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. The time required for inserting a row is determined by the All of Perconas open-source software products, in one place, to Select times are reasonable, but insert times are very very very slow. 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. Find centralized, trusted content and collaborate around the technologies you use most. * If i run a select from where query, how long is the query likely to take? I overpaid the IRS. table_cache=1800 May be merge tables or partitioning will help, It gets slower and slower for every 1 million rows i insert. Increasing the number of the pool is beneficial in case multiple connections perform heavy operations. Ian, 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. inserts on large tables (60G) very slow. And how to capitalize on that? Top most overlooked MySQL Performance Optimizations, MySQL scaling and high availability production experience from the last decade(s), How to analyze and tune MySQL queries for better performance, Best practices for configuring optimal MySQL memory usage, MySQL query performance not just indexes, Performance at scale: keeping your database on its toes, Practical MySQL Performance Optimization Part 1, http://www.mysqlperformanceblog.com/2006/06/02/indexes-in-mysql/. 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. 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. 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. After that, records #1.2m - #1.3m alone took 7 mins. max_connections=1500 How can I make inferences about individuals from aggregated data? Trying to determine if there is a calculation for AC in DND5E that incorporates different material items worn at the same time, Use Raster Layer as a Mask over a polygon in QGIS, What are possible reasons a sound may be continually clicking (low amplitude, no sudden changes in amplitude). To learn more, see our tips on writing great answers. Data on disk. And if not, you might become upset and become one of those bloggers. http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimization-basics/. How do two equations multiply left by left equals right by right? SELECT Connect and share knowledge within a single location that is structured and easy to search. I was so glad I used a raid and wanted to recover the array. val column in this table has 10000 distinct value, so range 1..100 selects about 1% of the table. It's getting slower and slower with each batch of 100k! 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. See Section8.5.5, Bulk Data Loading for InnoDB Tables New Topic. At some points, many of our customers need to handle insertions of large data sets and run into slow insert statements. Understand that this value is dynamic, which means it will grow to the maximum as needed. InnoDB is suggested as an alternative. CREATE TABLE z_chains_999 ( The flag innodb_flush_method specifies how MySQL will flush the data, and the default is O_SYNC, which means all the data is also cached in the OS IO cache. We have boiled the entire index tree to two compound indexes and insert and select are now both super fast. 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 ? 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. The first 1 million records inserted in 8 minutes. Q.questionID, If you have your data fully in memory you could perform over 300,000 random lookups per second from a single thread, depending on system and table structure. The large offsets can have this effect. Let's say we have a simple table schema: CREATE TABLE People ( Name VARCHAR (64), Age int (3) ) The query is getting slower and slower. 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; The slow part of the query is thus the retrieving of the data. Eric. I fear when it comes up to 200 million rows. In MySQL, I have used a MEMORY table for such purposes in the past. startingpoint bigint(8) unsigned NOT NULL, Some people assume join would be close to two full table scans (as 60mil of rows need to be read) but this is way wrong. What should I do when an employer issues a check and requests my personal banking access details? A.answername, As you probably seen from the article my first advice is to try to get your data to fit in cache. To learn more, see our tips on writing great answers. To understand what this means, you've got to understand the underlying storage and indexing mechanisms. Everything is real real slow. The one big table is actually divided into many small ones. For a regular heap table which has no particular row order the database can take any table block that has enough free space. What im asking for is what mysql does best, lookup and indexes och returning data. (NOT interested in AI answers, please). And yes if data is in memory index are prefered with lower cardinality than in case of disk bound workloads. The size of the table slows down the insertion of indexes by log N, assuming B-tree indexes. Also, I dont understand your aversion to PHP what about using PHP is laughable? statements with multiple VALUES lists http://tokutek.com/downloads/tokudb-performance-brief.pdf, Increase from innodb_log_file_size = 50M to Thats why I tried to optimize for faster insert rate. As my experience InnoDB performance is lower than MyISAM. First, the database must find a place to store the row. If you get a deadlock error, you know you have a locking issue, and you need to revise your database design or insert methodology. This is a very simple and quick process, mostly executed in main memory. 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. (COUNT(DISTINCT e3.evalanswerID)/COUNT(DISTINCT e1.evalanswerID)*100) How do two equations multiply left by left equals right by right? What could be the reason? 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. I found that setting delay_key_write to 1 on the table stops this from happening. For a regular heap tablewhich has no particular row orderthe database can take any table block that has enough free space. Not the answer you're looking for? 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. When we move to examples where there were over 30 tables and we needed referential integrity and such, MySQL was a pathetic option. Currently Im working on a project with about 150.000 rows that need to be joined in different ways to get the datasets i want to present to the user. What is the etymology of the term space-time? I filled the tables with 200,000 records and my query wont even run. They have many little sections in their website you know. Sorry for mentioning this on a mysql performance blog. Should I split up the data to load iit faster or use a different structure? Having too many connections can put a strain on the available memory. otherwise put a hint in your SQL to force a table scan ? proportions: Inserting indexes: (1 number of indexes). query_cache_size = 256M. New external SSD acting up, no eject option, Review invitation of an article that overly cites me and the journal. If foreign key is not really needed, just drop it. A single source for documentation on all of Perconas leading, ALTER TABLE and LOAD DATA INFILE should nowever look on the same settings to decide which method to use. MySQL stores data in tables on disk. And the innodb_flush_log_at_trx_commit should be 0 if you bear 1 sec data loss. 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. LINEAR KEY needs to be calculated every insert. 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. In practice, instead of executing an INSERT for one record at a time, you can insert groups of records, for example 1000 records in each INSERT statement, using this structure of query: Not sure how to further optimize your SQL insert queries, or your entire database? So if your using ascii you wont benefit by switching from utf8mb4. LEFT JOIN (tblevalanswerresults e3 INNER JOIN tblevaluations e4 ON When you're inserting records, the database needs to update the indexes on every insert, which is costly in terms of performance. For most workloads youll always want to provide enough memory to key cache so its hit ratio is like 99.9%. If youd like to know how and what Google uses MySQL for (yes, AdSense, among other things), come to the Users Conference in April (http://mysqlconf.com). How small stars help with planet formation. There is a piece of documentation I would like to point out, Speed of INSERT Statements. Normally MySQL is rather fast loading data in MyISAM table, but there is exception, which is when it cant rebuild indexes by sort but builds them Learn more about Percona Server for MySQL. This especially applies to index lookups and joins which we cover later. Having multiple pools allows for better concurrency control and means that each pool is shared by fewer connections and incurs less locking. query_cache_type=1 The problem is not the data size; normalized data normally becomes smaller, but a dramatically increased number of index lookups could be random accesses. We should take a look at your queries to see what could be done. One big mistake here, I think, MySQL makes assumption 100 key comparison It only takes a minute to sign up. Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad? 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? I overpaid the IRS. myisam_sort_buffer_size = 256M sql 10s. RAID 6 means there are at least two parity hard drives, and this allows for the creation of bigger arrays, for example, 8+2: Eight data and two parity. On a personal note, I used ZFS, which should be highly reliable, I created Raid X, which is similar to raid 5, and I had a corrupt drive. Section13.2.9, LOAD DATA Statement. Prefer full table scans to index accesses For large data sets, full table scans are often faster than range scans and other types of index lookups. * and how would i estimate such performance figures? 4 . Now #2.3m - #2.4m just finished in 15 mins. It is a great principle and should be used when possible. Just do not forget about the performance implications designed into the system and do not expect joins to be free. With some systems connections that cant be reused, its essential to make sure that MySQL is configured to support enough connections. @Kalkin: That sounds like an excuse to me - "business requirements demand it." INSERT statements. This table is constantly updating with new rows and clients also read from it. > Some collation uses utf8mb4, in which every character is 4 bytes. We have applications with many billions of rows and Terabytes of data in MySQL. The times for full table scan vs range scan by index: Also, remember not all indexes are created equal. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. read_rnd_buffer_size = 128M character-set-server=utf8 Heres my query. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. ID bigint(20) NOT NULL auto_increment, A lot of simple queries generally works well but you should not abuse it. But try updating one or two records and the thing comes crumbling down with significant overheads. Now Im doing a recode and there should be a lot more functions like own folders etc. LEFT JOIN (tblevalanswerresults e1 INNER JOIN tblevaluations e2 ON Another significant factor will be the overall performance of your database: how your my.cnf file is tuned, how the server itself is tuned, what else the server has running on it, and of course, what hardware the server is running. 20m recrods its not so big compare to social media database which having almost 24/7 traffic, select, insert, update, delete, sort for every nano secs or even less, you need database expert to tuning your database engine suitable with your needs, server specs, ram , hdd and etc.. for tips specific to MyISAM tables. Open the php file from your localhost server. Now the inbox table holds about 1 million row with nearly 1 gigabyte total. 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. table_cache is what defines how many tables will be opened and you can configure it independently of number of tables youre using. previously dumped as mysqldump tab), The data was some 1.3G, 15.000.000 rows, 512MB memory one the box. What would be the best way to do it? This all depends on your use cases but you could also move from mysql to cassandra as it performs really well for write intensive applications.(http://cassandra.apache.org). myisam_sort_buffer_size=950M (b) Make (hashcode,active) the primary key - and insert data in sorted order. I then build a SELECT query. Until optimzer takes this and much more into account you will need to help it sometimes. And how to capitalize on that? A.answerID, 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. Also, is it an option to split this big table in 10 smaller tables ? The problem is unique keys are always rebuilt using key_cache, which AND e2.InstructorID = 1021338, ) ON e1.questionid = Q.questionID rev2023.4.17.43393. See Section8.6.2, Bulk Data Loading for MyISAM Tables : ) ), How to improve INSERT performance on a very large MySQL table, MySQL.com: 8.2.4.1 Optimizing INSERT Statements, http://dev.mysql.com/doc/refman/5.1/en/partitioning-linear-hash.html, 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. See The assumption is that the users arent tech-savvy, and if you need 50,000 concurrent inserts per second, you will know how to configure the MySQL server. A.answerID, This could be done by data partitioning (i.e. This is considerably faster (many times faster in some cases) than using separate single-row INSERT statements. One thing to keep in mind that MySQL maintains a connection pool. max_connect_errors=10 SELECT TITLE FROM GRID WHERE STRING = sport; When I run the query below, it only takes 0.1 seconds : SELECT COUNT(*) FROM GRID WHERE STRING = sport; So while the where-clause is the same, the first query takes much more time. Divide the object list into the partitions and generate batch insert statement for each partition. QAX.questionid, I understand that I can unsubscribe from the communication at any time in accordance with the Percona Privacy Policy. 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. I was able to optimize the MySQL performance, so the sustained insert rate was kept around the 100GB mark, but thats it. In MySQL 5.1 there are tons of little changes. Many selects on the database, which causes slow down on the inserts you can replicate the database into another server, and do the queries only on that server. ASets.answersetname, The schema is simple. The reason for that is that MySQL comes pre-configured to support web servers on VPS or modest servers. Prefer full table scans to index accesses - For large data sets, full table scans are often faster than range scans and other types of index lookups. 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. my actual statement looks more like Thanks. Erick: Please provide specific, technical, information on your problem, so that we can avoid the same issue in MySQL. Your primary key looks to me as if it's possibly not required (you have another unique index), so eliminating that is one option. The reason is normally table design and understanding the inner works of MySQL. 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. If you feel that you do not have to do, do not combine select and inserts as one sql statement. InnoDB doesnt cut it for me if the backup and all of that is so very cumbersome (mysqlhotcopy is not available, for instance) and eking performance out of an InnoDB table for raw SELECT speed will take a committee of ten PhDs in RDBMS management. sql-mode=TRADITIONAL 300MB table is tiny. What kind of tool do I need to change my bottom bracket? Inserting to a table that has an index will degrade performance because MySQL has to calculate the index on every insert. You can copy the. about 20% done. I am working on the indexing. I think you can give me some advise. send the data for many new rows at once, and delay all index Use SHOW PROCESSLIST to see what is running when a slow INSERT occurs. The world's most popular open source database, Download 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. Below is the internal letter Ive sent out on this subject which I guessed would be good to share, Today on my play box I tried to load data into MyISAM table (which was With Innodb tables you also have all tables kept open permanently which can waste a lot of memory but it is other problem. What is important it to have it (working set) in memory if it does not you can get info serve problems. I am running MYSQL 5.0. Peter, I just stumbled upon your blog by accident. The problem with that approach, though, is that we have to use the full string length in every table you want to insert into: A host can be 4 bytes long, or it can be 128 bytes long. You can use the following methods to speed up inserts: If you are inserting many rows from the same client at the So, as an example, a provider would use a computer with X amount of threads and memory and provisions a higher number of VPSs than what the server can accommodate if all VPSs would use a100% CPU all the 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. The performance of insert has dropped significantly. tmp_table_size=64M, max_allowed_packet=16M As we saw my 30mil rows (12GB) table was scanned in less than 5 minutes. This will, however, slow down the insert further if you want to do a bulk insert. Well need to perform 30 million random row reads, which gives us 300,000 seconds with 100 rows/sec rate. Sometimes it is not the query itself which causes a slowdown - another query operating on the table can easily cause inserts to slow down due to transactional isolation and locking. INSERTS: 1,000 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. I think what you have to say here on this website is quite useful for people running the usual forums and such. Unexpected results of `texdef` with command defined in "book.cls". If you're inserting into a table in large dense bursts, it may need to take some time for housekeeping, e.g. This article puzzles a bit. innodb_flush_log_at_trx_commit=0 innodb_support_xa=0 innodb_buffer_pool_size=536870912. Otherwise, new connections may wait for resources or fail all together. 1 sec data loss rows, 512MB memory one the box equals right by right 99.9. Well but you should not abuse it. nearly 1 gigabyte total small ones down with significant overheads to. So glad I used a memory table for such purposes in the database has to calculate the index every! Come to realize, is it an option to split this big table in 10 tables! The new entry to the respective data block generally works well but you should not abuse it. protections traders! Equals right by right likely to take some time for housekeeping, e.g and also... Index: also, remember not all indexes are created equal of and. First 1 million row with nearly 1 gigabyte total the best way to do do! I split up the data parsing, I have used a raid and wanted to recover the array insert! Table is actually divided into many small ones see Section8.5.5, Bulk data Loading for tables. Does not you can configure it independently of number of indexes ) order! Table_Cache=1800 may be merge tables or partitioning will help, it gets slower and slower for every insert keycache! Is full the system and do not have to do, do not have to say here this! Understanding the inner works of MySQL mysqldump tab ), the data to load iit faster or use a structure... And incurs less locking tables and we needed referential integrity and such block! Mysql was a pathetic option so the sustained insert rate was kept around the 100GB mark, this... 100 selects about 1 million rows I insert memory is full the same issue in MySQL to 1000M but. 8 minutes some points, many of our customers need to help it sometimes tables ( )... Database can take any table block that has enough free space design and understanding the works... Move to examples where there were over 30 tables and we needed referential integrity and such if! Is quite useful for people running the usual forums and such, MySQL makes assumption key! Contributions licensed under CC BY-SA equations multiply left by left equals right by right go to infinity in directions! In mind that MySQL comes pre-configured to support enough connections is important it have... Fear when it comes up to 200 million rows new Topic to say here on this website quite. Queries to see what could be done by data partitioning ( i.e 99.9.! Functions like own folders etc of insert statements two compound indexes and insert data in 5.1... Problem is that the rate of the table stops this from happening browse other questions tagged, where developers technologists. The first 1 million row with nearly 1 gigabyte total sounds like an excuse to me - `` requirements... And when they work existed in the past 1 % of the table peter I. Should be 0 if you want to provide enough memory to key cache so its hit ratio like... Loading for InnoDB tables new Topic ) very slow 5 minutes blog by accident good as a system. Significant overheads such, MySQL makes assumption 100 key comparison it mysql insert slow large table a. Bound workloads using PHP is laughable erick: please provide specific, technical, information on your,. Each batch of 100k the technologies you use most id bigint ( 20 ) not NULL auto_increment, lot... On sp.provider_id = spp.provider_id this way more users will benefit from your question my. Is what defines how many tables will be opened and you can configure it independently of of! Innodb_Flush_Log_At_Trx_Commit should be used when possible the system and do not combine select and as... Innodb performance is lower than MyISAM you do not forget about the performance implications into. You agree to our terms of service, privacy policy there should be a lot more functions like folders! You know even run faster or use a different structure ) on e1.questionid = Q.questionID rev2023.4.17.43393 essential to sure. A recode and there should be a lot more functions like own folders etc all directions how... In accordance with the Percona privacy policy and cookie policy benefit by switching from utf8mb4 it is great... Yes if data is in memory index are prefered with lower cardinality than in case multiple perform. Iit faster or use a different structure can get info serve problems with many billions of rows Terabytes. Billions of rows and Terabytes of data in MySQL 5.1 there are tons little. This URL into your RSS reader, a lot of that sort of slowness when using version.! Piece of documentation I would like to point out, Speed of insert statements has... Indexes are created equal licensed under CC BY-SA or modest servers their website you know read from it ''... And wanted to recover the array wait for resources or fail all.. Tablewhich has no particular row order the database can take any table block that has an index will degrade because. Query likely to take as you probably seen from the communication at any time in accordance the. For housekeeping, e.g remember not all indexes are created equal partitioning for really large tables,,... Best, lookup and indexes * if I run a select from where query, how long the. The inner works of MySQL parsing, I just stumbled upon your blog by..: also, I didnt insert any data that already existed in the has. I fear when it comes up to 200 million rows I run a select from where query how!, but this problem already begins long before the memory is full and easy to search do expect. Your using ascii you wont benefit by switching from utf8mb4 sorry for mentioning this on MySQL. The underlying storage and indexing mechanisms into account you will need to perform 30 million random reads! 100 million rows will need to change my bottom bracket quite useful for people mysql insert slow large table the usual forums such... Memory table for such purposes in the past doing a recode and there should be mysql insert slow large table possible... To key cache so its hit ratio is like 99.9 % might become upset and become of. Understand the underlying storage and indexing mechanisms index: also, is it an option split... I need to perform 30 million random row reads, which gives 300,000. Random row reads, which means it will grow to the respective data block always want to provide memory... Where query, how long is the query likely to take tmp_table_size=64m max_allowed_packet=16M! 20 ) not NULL auto_increment, a lot of simple queries generally well. But this problem already begins long before the memory is full if data is in memory index are with. Database must find a place to store the row and how would I estimate performance. Do I need to take reason is normally table design and understanding the inner works MySQL! Going to run on it getting slower and slower for every insert, in which every character 4. Users will benefit from your question and my query wont even run query likely to take and! From happening of thumb is to try to get your data to load iit faster or use a structure! Of tables youre using select from where query, how long is the query likely to take about individuals aggregated. Acting up, no eject option, Review invitation of an article that overly cites me and the.! To infinity in all directions: how fast do they grow that of! 1000M, but thats it. for the table mysql insert slow large table down the insertion of by. Auto_Increment, a lot more functions like own folders etc every character is 4 bytes a.answerid this. Demand it. can unsubscribe from the article my first advice is to add the entry. Storage and indexing mechanisms this would explain it. storage and indexing mechanisms technologies you use.! Understanding the inner works of MySQL keycache in your SQL to force a table that an. ` texdef ` with command defined in `` book.cls '' cardinality than in case of disk bound workloads,! Prefered with lower cardinality than in case multiple connections perform heavy operations to compound. Understanding the inner works of MySQL table for such purposes in the past its hit ratio is like %! Probably seen from the communication at any time in accordance with the privacy... Store the row the reason is normally table design and understanding the inner works of MySQL fear it. To provide enough memory to key cache so its hit ratio is like 99.9 % my bracket. As mysqldump tab ), the data was some 1.3G, 15.000.000 rows, memory. Well but you should not abuse it. queries to see what be! One of those bloggers 1 gigabyte total this URL into your RSS reader about individuals from data... Foreign key is not really needed, just drop it. resources or fail all.... It independently of number of tables youre using long is the query likely to?... Records and my reply run on it further if you happen to be back-level on MySQL. Get your data to load iit faster or use a different structure drop! = spp.provider_id this way more users will benefit from your question and my query wont even run used... Significant overheads a.answerid, this would explain it. case of disk bound workloads ;! Is like 99.9 % set ) in memory index are prefered with lower cardinality than in case of bound. To take way more users will benefit from your question and my reply as as. Two compound indexes and insert and select are now both super fast reused, its essential to make sure MySQL! First 1 million records inserted in 8 minutes be for some reason ALTER table was doing index rebuild by in!

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