In the database structured query language (SQL), the DELETE statement removes one or more records from a table.

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Approaches for deleting unnecessary records from tables

We have a database which stores the temperatures of 20 thermometer every 7 seconds. We want to delete all records in the way that every minute holds just one tempereature instead of 8 which are older ...
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INSERT and DELETE in single operation (moving from one table to other)

Stemming from this question, I am going to use that complex sort's results to decide which rows' data to move from one table to another. Though I have not yet tried it, I think there should be no ...
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what is the quickest way to delete duplicate rows?

I need to delete duplicate rows from a large table. what is the best way to achieve that? currently I use this algorithm: declare @t table ([key] int ) insert into @t select 1 insert into @t ...
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Query optimization in case of TIMESTAMPDIFF

I have a table where I need to delete all rows older than 5 hours. Currently I'm doing: delete from my_table where TIMESTAMPDIFF(HOUR, from_unixtime(round(created_on/1000)), now()) > 5 The ...
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What is the best way to purge data from a table with minimum damage to performance?

When you purge records from a database table, deleting them, you have impact on the logical and physical structure of the target table, as well as indexes and statistics. What maintenance should be ...
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SQL Delete rows where a dataname will equal mulitple variables

Researching similar common queries have really helped but I am still none the wiser as to my issue. To note that the database I intend to use this on contains around 1000 rows (same 2 columns listed ...
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MySQL: update instead of delete if foreign key constraint?

I have a bit of a strange question. I know about insert on duplicate key update. My question is, is there something similar for deletes that fail because of foreign key constraints? For example: ...
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Freeing space after deleting rows [duplicate]

I have a SQL Server 2008 instance and one table is quite large (log data) so I delete old logs. Now I start to read articles on this problem, here is one. As I see it there is no solution! If I ...
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Delete from table where multiple fields match select subquery from other table

I want to delete an entry in a table where multiple fields match the results of another select subquery which takes data from another table. This is what I have so far, though it doesn't work: ...
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Delete entry from related tables

I can not use InnoDB engine because of some dependency troubles in LuaSQL and PtokaX. My current query is something like: DELETE e.*, m.* FROM entries e INNER JOIN magnets m ON m.eid = e.id ...
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Can I use table aliases in a MySQL DELETE statement?

This does not work: DELETE FROM topics AS t , posts AS p USING t INNER JOIN p WHERE t.id=p.topic_id AND t.id = '5599'; whereas this does: DELETE FROM topics, posts USING topics INNER JOIN posts ...
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How to delete duplicate rows in merge replication

Somehow two rows in a table that is party to merge replication are identical, including their rowguid. I have no idea how this happened, it is only with two rows in my entire database (which is used ...
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Oracle SQL script - passing a parameter

I have an Oracle SQL script like this: delete FROM activ_princ where id in (select ap.id FROM activ_princ ap inner join sect e on e.id=ap.FK_ID_SECTIUNE_e inner join chest ch on ...
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MySQL Deadlock - accessing different primary key values also creating deadlock

I went through MySQL logs and found the reason for deadlock 1st thread is trying to execute below query. Which is waiting for thread 2. UPDATE M_SAMP SET MM_Q_IND=0 WHERE M_ID IN (SELECT M_ID FROM ...
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Remove all records with duplicates in db2. (Not just the duplicate records)

How can I remove all the records with duplicates in db2. I have looked at various answers but they only remove the duplicates leaving one record from that set in the table. This is what I found ...
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PostgreSQL : dependencies on a schema

I need to delete a schema in my PostgreSQL database. I would like to make sure that the schema is not used in another schema (for instance : this schema is used for a view in another one). Is there a ...
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mysqldump: replace drop table in output with delete?

I am using mysqldump to dump some records in a table: mysqldump mydatabase mytable --where="field=value" this emits script that includes drop table mytable statement. Since I use the --where ...
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Large table delete in mysql

I want to delete a table with 10,000,000 records. Due to some restrictions I can't do truncate on that table (I don't have the DROP privilege), I can think of two options: DELETE QUICK To set some ...
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Fastest way to delete matching rows in MySQL?

I have more than 10 million records in a table. I want to delete the records where the email column contains .ac.. What is the fastest method to perform the task? Table Schema CREATE TABLE `master` ...
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Mysql setting a record as deleted or archive

Is there any way to omit some records in mysql select statement and not deleting them? We can easily add a column for example deleted and set it to 1 for deleted ones and keep them but the problem is ...
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Delete by primary key takes too long

What would make a query that deletes a row using the primary key of the table .. take too long ? This is a table with about 1.4M rows that gets .. 70%/30% read/write . I don't know where to look. ...
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Deny insert/delete for all users in SQL Server 2005

In our database we have about 20 users, that is used be some program (and users are added with this program). Now there was new requirement to use 2 database and do not allow delete data from one ...
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MySQL - Deleting old data; Select with index taking time

I am a bit confused about 2 queries. First query I am running on a 50m rows table by index on a timestamp row with a limit, I would expect the query to be immediate regardless of the size of the ...
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Configure MariaDB to log row deletion ONLY

I'm investigating some rows/tables that intermittently go missing on a Magento site, and of course there's no entries in the error log. (I suspect Magento queries/rules or human error might be the ...
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Force index on a delete

UPDATE backup.records FORCE INDEX(IDX_records_deviceId) SET readyToBeDeleted = 1 WHERE deviceId = 226219 AND timestamp <= 1445255546 *** (1) WAITING FOR THIS LOCK TO BE GRANTED: RECORD LOCKS space ...
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Delete rows where matched value is twice as much

I'm trying to match two tables with two columns, table1 and table2. Each has id and price columns. I want the query to match each id and compare the price, then delete the row if the price in the ...
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To trigger or not to trigger- That is the question

I have a mysql table that tracks page views. Each row includes a date stamp. I want to remove all rows that are over 30 days old on a regular basis. Could, or should, I trigger an action on each ...
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DELETE statement execution cancellation in SSMS

I ran a delete statement with wrong WHERE condition (which deletes all records from table instead of just 10 records) but during execution I found it and CANCELLED the execution in Management Studio, ...
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Delete Duplicates Leaving One of Two Identical Records [closed]

Delete Duplicates Leaving One of Two Identical Records One of my MySQL database tables contains four BLObs in each row. When it was first set up the table had no keys. However when I now try to add a ...
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DELETE seems to hang

The following command: DELETE FROM hours WHERE id IN (SELECT id FROM holdkey WHERE persons_id=60) seems to hang indefinitely. However, the corresponding SELECT * command completes in a fraction of ...
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Can having a LIMIT on DELETE degrade performance dramatically?

I have a database project in php and mysql. For, hopefully redundant, data security I added a LIMIT 1 to the delete($uniqueID) php function we use. Nobody cared because records really aren't ...
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MySQL master master replication, safe to delete rows on both masters?

We have a MySQL (v5.1.61) cluster with two masters (and two slaves). We have a table logs with a primary key column logID. This log table grows rather huge, and we'd like to delete data from it. So I'...
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mysql query - how to delete duplicates based on highest int?

I'm running a reverse auction website and I need to delete the duplicate bids and keep only the highest amount . lastPriceBid_rounded is the "amount". The duplicate is defined by the userId. +-------...
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Delete word, its meanings, its meaning's example sentences from DB

I have three tables as below (simplified for demonstration): words ===== integer id text word meanings ======== integer id integer word_id text meaning examples ======== integer id integer ...
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Changing Action on Delete to Cascade

We have a rather big database (about 400'000'000 records) in roughly 100 tables. The foreign keys in these tables are defined, so that No Action is taken, when deleting data from a table. We now have ...
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Delete Query Issue in MySQL and PHPMyAdmin [closed]

I am facing a strange issue with MySQl. I am using PHP and MySQL to built an app. When I am trying to delete records from the table it runs successfully but no record is deleted from the database. ...
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Is it possible to cascade delete a column value? [duplicate]

So say I delete catID from table A and table B has the same foreign key value? It's hard to explain so I'll try and show you with the two images below: items table Is it possible to delete the ...
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Should I stop an awfully inefficient MySQL DELETE statement?

I'm running the following statement on MySQL 5.5 in a 1GB 1CPU SSD virtual machine from Linode: DELETE table FROM ( SELECT MAX(id) id, field FROM table GROUP BY field ) temp_table INNER ...
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To find data in Multiple tables and delete it?

I am using a PostgreSQL server. Suppose I have 200 values in a master table that need to be deleted. There are 9 other tables referencing this master table. The other 9 tables not only reference the ...
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MySQL - Preventing lock wait timeout when deleting rows from self

I have a table of around 500k rows (not big data), that I need to query against itself and then delete some of the rows which don't match the filters. At the moment my query looks like this: DELETE ...
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MySQL bulk deletions

I am currently looking at how to most efficiently delete rows from a table in bulk. The database I'm using is MySQL with innodb. The table I want to delete from can be any size, but will usually be ~...
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Delete rows while updating references

Suppose I have a person table with an id and some other columns. Other tables reference the person table using ON UPDATE CASCADE. for instance: CREATE TABLE person (id int PRIMARY KEY); CREATE TABLE ...
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Low batch Batchrequests/sec

I am running this query to do massive deletion in my database. I am looking at Batchrequests/sec and it is quite low (like 15% of what my server can handle) Is there any way to rewrite this query to ...
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Why is this query stuck if there are no waits?

I am working with a vendor's activity logging system. One of the tables has 70+ million records and is constantly increasing at several hundred records per minute. They have a utility to delete old ...
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Importing large .sql file stops before even midway and starts deleting

Okay so i'm trying to import my minecraft servers .sql file into database and after first 1GB of importing data it stops without error and starts deleting what already has been imported any ideas? ...
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How do automaticly delete rows from other tables

I have a MySql DB. I have a table - recipes. Also have 2 tables -ingredients and instructions. both have for each entry - a foreign key to the related recipe. I want that when I delete an entry from ...
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Optimization: Delete with Top and minimize the where clause date range

I have a delete statement that get run repetitive until all the data are removed. Delete TOP (1000) From Log Where CreationDate < '2011-Dec-31' AND pKey NOT IN (...) I am considering of ...
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Delete rows in parent table based on criteria in child table - Oracle

I have a table B with a foreign key to table A. I want to DELETE some rows in table B, and I also want to DELETE their parent rows in table A. However, the delete criteria is based on table B. The ...
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MySQL Large DELETE with JOINs

I have a large table players with ~20MM rows which joins to a table stats with ~300MM rows, among others (photos, ...). I want to DELETE all records for players that were born_on before 1950. I ...
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Clear out remnant LDF log files of Sharepoint DB not visible on SBS 2008 Domain Server?

Typical ways for dealing with LDF files that take up a lot of space, recommend these processes to shrink/ eliminate the drive space being occupied. http://www.sharepointboris.net/2008/10/sharepoint-...