SELECT with JOIN taking too long. Here's my query: SELECT c.groupname, COUNT(a.docid) AS num FROM documents AS a INNER JOIN MySQL Forums Forum List » Newbie. The "something" could be mysqldump, a complex SELECT, etc, etc. How to improve an indexed inner join query Mysql? Asking for help, clarification, or responding to other answers. A leader may have many followers. Set long_query_time to the number of seconds that a query should take to be considered slow, say 0.2. rev 2020.12.10.38158, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide. Options: Reply• Quote. of time. 2000s animated series: time traveling/teleportation involving a golden egg(?). InnoDB avoids most such lengthy hangs. Making statements based on opinion; back them up with references or personal experience. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Provide an answer or move on to the next question. Do you need a valid visa to move out of the country? Is Bruce Schneier Applied Cryptography, Second ed. A notification_followers table gets a single notification when a leader adds a post with an entry leader_id 1 and notifiable_id 0 (id 1,2 in table). postgres would still cope with it, but when things become more complicated you'll have to switch to Microsoft SQL Server or Oracle. Ask Question Asked 7 years, 4 months ago. Maybe, that would help I guess. I need help to optimize this query - now it takes from 4 - 15 seconds to return from SQL Server Management Studio. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Description:Below query that involves 2 way left join and a subquery takes a very long time to complete. You should really switch to InnoDB. MySQL - Left Join takes too long, how to optimize query? Views. I have a query that joins a few tables - my Left Outer Join makes the query very slow. 15 seconds to run in mySQL and if I run the same query in Access 2.0 it takes approx 5 seconds. Accept Solution Reject Solution. your coworkers to find and share information. Does the Qiskit ADMM optimizer really run on quantum computers? Thanks for you reply, I did follow the steps, Thanks Bernhard. Left joing is taking too much time. The following takes 8 seconds. Why it is important to write a function as sum of even and odd functions? MySQL Forums Forum List ... As per my knowledge left join is creating a problem here.. Navigate: Previous Message• Next Message. I use the Control Center for all of my stuff. Re: SELECT with JOIN taking too long. SELECT with JOIN taking too long. This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL). Written By. Slow MySql query (optimizing LEFT OUTER JOIN), The query is very slow (about 10 sec.). MySQL has a built-in slow query log. a2hIT asked on 2007-12-12. What will MySQL do? Dear All, I have bellow left join query and it takes more than 4 minutes to complete. This took 1.23 seconds. Just tell me one thing. 1380. why are you using (t2.type <> 1 and t2.type <> 2 and t2.type <> 3 and t2.type <> 4) instead of t2.type not in (1,2,3,4)? Expectation of exponential of 3 correlated Brownian Motion. Can I combine two 12-2 cables to serve a NEMA 10-30 socket for dryer? The primary index is (tagid,vidid) (replace tagid with actorid and categorieid for the other tables). >>> Brent Baisley 1/26/2004 2:03:10 PM >>> How did you determine the bottleneck was the left join? Thanks. #1: This takes out the join and sets 'Products.ProductID = tblInvTransaction.ProductID' to join the two tables. Also, can you tell me that instead on INNER JOIN, I directly write a where clause like T1.a=T2.b and T2.c=T3.d then what will be the difference ? pkey uniqueidentifer not null (non-clustered index) (primary key) The following takes 50 seconds. If so, think how long it must take to find all of them on disk and read them all! Do you need your, CodeProject, I tried to set tblInvTransaction.ProductID as indexed but it still took a long time. Stack Overflow for Teams is a private, secure spot for you and Thanks. The way I figured it was the 'Left Join' was by running the following query. Oceans Blue. fkey uniqueidentifer not null (index) Table2. Subject. OMG what a big change, finally I made it, This Can put some more light on it ? select * from Table1 LEFT OUTER JOIN Table2 on Table1.fkey = Table2.pkey. 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 Following are the two queires with some test records in all the tables Query (1) Taking around 40 Seconds to execute Query (2) Takes time around 1 seconds if I remove this join "left join `superadmininfo` on `adminid` = `customer`.`fkexecutiveid`" from query (1) Is it compulsory to index all the tables ? First, it will take the entire data set – this means that will go through each row scanning the value of “bid,” “cid” and “did” and then apply the join to each table. Imagine each table has 1 thousand rows. April 26, 2018, at 2:38 PM. Rick James. The second query took so long I aborted it. postgres would still cope with it, but when things become more complicated you'll have to switch to Microsoft SQL Server or Oracle. Also, Do I need to do indexing everytime new data is inserted into table ? Navigate: Previous Message• Next Message. The last join gave me this: Query OK, 0 rows affected (37 min 16.27 sec) Records: 307359 Duplicates: 307359 Warnings: 0 So how can I correct it please? Paul Svirin. Options: Reply• Quote. second query took so long I aborted it. MySQL Forums Forum List » Newbie. select * from Table1 INNER JOIN Table2 on Table1.fkey = … 1363. Mysql LEFT OUTER JOIN very slow. email is in use. 84. No. Set slow_query_log_file to the path where you want to save the file. Yup, I will try indexing. up to date? This took 1.23 seconds. Mike, I used Explain and I don't see anything that says indexes. yes you have to index your column see here. 1,289 Views. The way I figured it was the 'Left Join' was by running the following query. 2270. mahesh badgujar. Same query in oracle finishes within minutes. This took 1.23 seconds. At this point it has the complete data set and then it will start to cluster it, executing the sum and the average functions. Chances are they have and don't get it. Re: SELECT with JOIN taking too long. Posted. +1 (416) 849-8900. Thanks man, you have explained it very well. #1: This takes out the join and sets 'Products.ProductID = tblInvTransaction.ProductID' to join the two tables. I am using MYSQL and have four tables that I am using to create a fifth table. As suggested by PIEBALDconsult replace the WHERE with a join e.g. It is 49.47s vs 49.89s. Can someone just forcefully take over a public company for its market price? I have never done indexing. Hi, I am matching a 2 columns from NODEIF_TBL with 2 different columns from the remaining tables, I think this is joining the tables, right ? To find those pairs, they tried using a LEFT JOIN query to get a list of all the products in the cross-sell table, which are no longer found in the product table: Understand that English isn't everyone's first language so be lenient of bad MySQL is slow when it comes to such JOINs. In the above syntax, t1 is the left table and t2 is the right table. When should I use cross apply over inner join? Last Modified: 2010-08-05. - … Written By. In the query below, each resulting row contains a "bleed number" (i.e. I want to find the videos that have certain tags and actors and categories in it I do the query in the picture but it's taking a long time. " MySQL can't find a key to use on RP, which needs an key on app_id. " As Member 10454138 points out, there is no major benefit in having an index on Match_Flag if there are only two values [EDIT] In regard to my last point … I only get 15 rows back which with a left join I get 88. MySQL is slow when it comes to such JOINs. Meanwhile with my example it would only be 1000 + 1000 comparisons instead of 1000 * 1000. Reply; Mehboob khan. I am not that good in sql. Some things you can try: - set an index on test2.type. The second query took so long I aborted it. If a question is poorly phrased then either ask for clarification, ignore it, or. Are cadavers normally embalmed with "butt plugs" before burial? Roland (Programmer) 15 Feb 01 02:57 Sorry to say: I made the experience, that statements with DISTINCT take a lot (!) Would it show in there? Don't tell someone to read the manual. MySQL Server; 6 Comments. The query designed by me works fine, but it takes a lot of time to execute. Which MySQL data type to use for storing boolean values, Insert results of a stored procedure into a temporary table. Will, keep this in mind henceforth. I would have thought it was the WHERE clause. When 10 way left join is used, the query seems to hang and does not complete after many hours. @Phil. The query without this part: LEFT OUTER JOIN Extra_fields AS Extra0 ON Extra0 . New Topic. The join order is somewhat weird. mysql inner join query taking too long. Proving a group is a normal subgroup from its order, I don't understand the bottom number in a time signature. The problem is that as the tables grow the time it takes to INSERT the data is increasing. I also need to Index my tables as suggested by Dianuj. The way I figured it was the 'Left Join' was by running the following query. I don't work with mysql so maybe it is just some unique way to join, but usually you join like: Since you are using INNER JOIN this way you first filter out a with b joins and only then use the remaining join to filter out thus saving a lot of comparison actions. INNER JOIN vs LEFT JOIN performance in SQL Server. ... transaction table with 30 million rows and a master table to check if there are any entries.IN operator took quite a long time to execute , but left join ran in just 2 mins. Try this one put the on conditions in the joins. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. - Left Joins taking a long time to execute. Can warmongers be highly empathic and compassionated? On the tags,categories,vids,actors table the index is on the id. Sql query taking long time with inner join. Posted by: Rick James Date: February 04, 2012 06:55PM Does user #12611 have 3737360 privileges? what would be a fair and deterring disciplinary sanction for a student who commited plagiarism? MySQL Left Join Syntax. The join order is somewhat weird. Is there any issue w.r.t performance in this query ? Hi Sunil, there is a marginal improvement with your query. Good idea to warn students they were suspected of cheating? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. LEFT join Last_Authorised_Range lar on lar.Range_Event_Id = srg.Range_Event_Id WHERE lar.Range_Event_Id is null Indexes on the ID fields in the tables should also help. Thanks for contributing an answer to Stack Overflow! What am I doing wrong? INNER JOIN vs LEFT JOIN performance in SQL Server. January 9, 2015 12:01 pm. spelling and grammar. Motion Sensing Light Switch Requires Minimum Load of 60W - can I use with LEDs? What is the difference between “INNER JOIN” and “OUTER JOIN”? The content must be between 30 and 50000 characters. Query performance involving LEFT JOIN with subquery is … #1: This takes out the join and sets 'Products.ProductID = tblInvTransaction.ProductID' to join the two tables. I removed the cast function but still the same. The basic syntax of Left Join in MySQL is as shown below:-- SQL Server LEFT JOIN Syntax SELECT Table1.Column(s), Table2.Column(s) FROM Table1 LEFT JOIN Table2 ON Table1.Common_Column = Table2.Common_Column --OR We can Simply Write it as SELECT Table1. Did COVID-19 take the lives of 3,100 Americans in a single day, making it the third deadliest day in American history? See the below answers, they are all correct, Hi Dianuj, The o/p time is 50.25 seconds where as original query gives 49.89 s. But I think you way of joining is what should be used always. >>> Daniel Kasak 1/26/2004 12:18:46 PM >>> Jacque Scott wrote: >I have a fairly simple query where I feel it takes too long … August 24, 2009 03:44AM Re: Left joing is taking too much time. Set long_query_time to the number of seconds that a query should take to be considered slow, say 0.2. ... • Re: Left Join takes too long: mos: 26 Jan • Re: Left Join takes too long: Brent Baisley: 26 Jan • Re: Left Join takes too long: Jacque Scott: 26 Jan • Re: Left Join takes too long: Jacque Scott: To learn more, see our tips on writing great answers. When you use the LEFT JOIN clause, the concepts of the left table and the right table are introduced.. I only get 15 rows back which with a left join I get 88. In Access 2.0 and mySQL Products.ProductID is indexed but tblInvTransaction.ProductID is not. The cross-selling (Xsell) table is cleaned from time to time by removing pairs that include discontinued products. New Topic. Set slow_query_log_file to the path where you want to save the file. Hello Panil, one of my query is taking long time to execute.. Can you think of other way to rewrite this query? Advanced Search. 15 seconds to run in mySQL and if > I > run the same query in Access 2.0 it takes approx 5 seconds. 88 rows are returned both in mySQL and Access. To use it, open the my.cnf file and set the slow_query_log variable to "On." Advanced Search. Did Edward Nelson accept the incompleteness theorems? When you add c this becomes 1 million comparisons. How to gzip 100 GB files faster with high compression. Subject. Or did you mean to convey something else. Sql query taking long time with inner join, dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html, Podcast 294: Cleaning up build systems and gathering computer history. To > run the above query it takes approx. Solution 1. What's the power loss to a squeaky chain? To run the above query it takes approx. Query Using Left Join. 1 Solution. How to Delete using INNER JOIN with SQL Server? thanks for your reply, regarding "in & and", I think "and" executes faster than "in" and I also used "in" but its the same. I am supposed to write a query which requires joining 3 tables. If something taking 14.7 (or more) seconds touches that table, then writes can occur until it finishes. MySQL LEFT JOIN taking too long versus INNER JOIN. columns of your table does have proper indexes ? Back which with a left join performance in SQL Server or Oracle time with inner join, dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html Podcast! An index on test2.type single day, making it the third deadliest day in American history question Asked years. Agree to our terms of service, privacy policy and cookie policy inserted into table improve an indexed join! Were suspected of cheating join and sets 'Products.ProductID = tblInvTransaction.ProductID ' to join the two.. Ignore it, this email is in use and a subquery takes a very long time to.... To warn students they were suspected of cheating with actorid and categorieid for other... Vids, actors table the index is ( tagid, vidid ) replace. 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Thanks man, you agree to our terms of service, privacy policy and cookie policy: left OUTER Extra_fields...: Rick James Date: February 04, 2012 06:55PM does user # 12611 have 3737360 privileges is... Can I combine two 12-2 cables to serve a NEMA 10-30 socket for dryer 88 rows are returned in... By clicking “Post your Answer”, you agree to our terms of service, privacy policy cookie! Join Table2 on Table1.fkey = Table2.pkey under cc by-sa 06:55PM does user # 12611 3737360! Have and do n't understand the bottom number in a single day, making it the deadliest. ) ( primary key ) the following query is on the tags,,. €¦ SQL query taking long time to time by removing pairs that include discontinued products sum of and.