UPDATE changes the values of the specified columns in all rows that satisfy the condition. Only the columns to be modified need be mentioned in the SET clause; columns not explicitly modified retain their previous values.

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1answer
87 views

Most efficient way to do many UPDATES in Postgresql

I have to update cca 2.5 milion rows in a table with cca 20 milion rows. The updated column value is based on value of another column, but another select is required to determine it's value. The ...
2
votes
1answer
3k views

Update all columns from another table

I need to update a table from another one, and I need to update all columns. Besides listing every column in the SET clause, is there a way to update them all at once? Like this: update tableA set * ...
2
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1answer
202 views

Updating column in underlying table causes massive transaction log growth

I have an underlying table ~14k records and an indexed view that contains ~11 million records. When updating a column in the small underlying table this seems to cause a massive transaction log entry ...
2
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1answer
1k views

Update one table from another table while sorting that table based on one column

This is the problem I'm trying to figure out in MySQL. We have an old table contains some forms submitted by our users. Somehow, the previous decision was each time a user comes to this survey, a new ...
2
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2answers
183 views

Help with tricky update statement

I've tried writting this update statement every possible way I can think of but I either wind up producing invalid results or run into a syntax barrier. I have two table variables: DECLARE ...
2
votes
2answers
59 views

How do you update a large MySQL table that's on a server?

I have an application on a web server. The PHP front end for the application queries a MySQL database which has a table that contains 60 million taken domain names. My application queries this ...
2
votes
1answer
239 views

Create a new table (multiple columns) by selecting random values from an existing table

I am stuck on the following task (PostgreSQL 9.3). Let's say we have the following table1 (which has 10k rows): table1: id 754 800 330 4 59 My goal is to create another table2 with two columns ...
2
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1answer
137 views

Does MySQL do UPDATE in place on NOT NULL column?

Assume I have a table like this in MySQL: CREATE TABLE Foo ( Key INT NOT NULL , MyCol INT NOT NULL PRIMARY KEY (Key)) And I execute a statement like this on: UPDATE Foo SET MyCol = 13 WHERE Key = ...
2
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1answer
299 views

Apply in a CSV file to multiple databases

Recently, I have been working with a client whom has asked us to provide their dataset for use in a mobile application we are making for them. The requirements for this project include the ability to ...
2
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1answer
592 views

Update ranking on table

I have two tables: mysql> desc rank ; +----------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
2
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0answers
45 views

How to optimize update using join in postgresql

I'm using PostgreSQL 9.3.5 on a CentOS system. I have a very large table (twenty million rows, 50+ column) that aggregates data from a few hundred systems. Several times a day each of the systems ...
2
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0answers
46 views

Unable to Update on SQL Server 2008 R2

This is a bit strange so bear with me please. After installing a new SQL Server 2008 R2 on a new server (Windows 2012 Standard) just like the production one, I tried to connect my web aplication ...
2
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1answer
29 views

Translate SQL Server update statement to MySQL

I have a development environment with MySQL and a production environment with SQL Server. This update statement works with SQL Server: UPDATE THIS SET <list_of_column_assignments> FROM ...
2
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1answer
1k views

Oracle 10g: Optimizing an update query that uses a subquery

I have the following query within a stored procedure, and I've been trying to improve its performance to no avail. UPDATE TBL_REPORTING REP SET (REP.ISSUER_ID, REP.ISSUER_NAME ) = ( ...
2
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0answers
178 views

How to execute a non-table-locking update operation on PostgreSQL? [closed]

Looking for a good way to update the value on a column for all the rows in a database (not huge, but big enough - about 10M records), without locking the whole table, so operations can continue while ...
2
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0answers
250 views

Best Practice to update columnstore indexed tables

I have a table with aprox. 22 Bn rows, for each month I have made one partition that and each partition has two data files. I created the columnstore index on this table and the performance ...
2
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1answer
2k views

I have to update all the rows of a Column in a table. Here is my query

So My tables are People: People_name(VARCHAR 100), People_id (INT, PRIMARY KEY AUTO INCREMENT) Tracks: Track_id(INT PRIMARY KEY), People_id_references (int ,Foreign key references ...
1
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4answers
531 views

Performance degradation while updating tables having 10s of millions of records

I want to update tables ( my be 20-30 ) having 10s of millions of records each. The problem is that it is taking too much time for the update process and also at that time CPU usage also goes very ...
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3answers
159 views

How to handle update or insert situations

From time to time my stored procedures looks like create procedure handle_data @fk int ,@value varchar(10) as begin if exists (select * from my_table ...
1
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3answers
3k views

Bulk update of all columns

I am wondering if PostgreSQL has an update query somewhat like their insert values syntax. I have an updated set of data in this form currently: INSERT INTO ...
1
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3answers
164 views

How to handle big data update based on excel spreadsheet

Scenario Select-based data is exported from DB to Excel spreadsheets. Some manual work is done on the excel files (filling missing data). Changed data from excel files is updated back to DB. ...
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3answers
111 views

How to map similar camelcased, pascalcased, underscored, lowerscored words to the same id?

I'm working on PostgreSQL and I have a table like this called words_table: I need all equivalent words (like software_design and software-design) to have its map value = to its word's equivalent ...
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2answers
109 views

Is column order reliable in UPDATE?

Can we reply on the order of columns in an UPDATE? SET @x = 0 UPDATE table1 SET col1=IF(col1 IS NULL, NULL, @x:=@x+col1), col2=IF(col2 IS NULL, NULL, @x:=@x+col2), col3=IF(col3 IS NULL, NULL, @x:=0) ...
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2answers
270 views

Dynamic UPDATE fails due to unwanted parenthesis around string in plpgsql

Using PostgreSQL 9.3.4 on Mac OSX 10.9.2 with Postgres.app. I want to apply a function to all columns in a table, specifically I want to trim white space. So far I've got this in a file test.sql: ...
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1answer
103 views

numbering rows consecutively for a number of tables

I have a number of tables, all containing attributes aid,bid,cid, and xid of type integer, other attributes may differ. For every (given) table T, I would like to order the rows according to ...
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2answers
143 views

How does optimistic locking actually enforce re-read/update?

My understanding of optimistic locking is that it uses a timestamp on each record in a table to determine the "version" of the record, so that when the record is access by multiple processes at the ...
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2answers
528 views

Way to update many (>3000) records with unique data, using a character limited web form

Okay, as you can probably tell from the last part of the title, this is a non-ideal situation. I'm using a piece of industry-specific web-interface software that I guarantee no one has ever heard of, ...
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3answers
149 views

Undo SQL UPDATE Azure DB

I have accidentally updated over 3,000 records in one of my tables hosted on Azure. This was not a transaction and I did not have any back ups for this table. I've read around and found ApexSQL Log ...
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2answers
209 views

Install SP 3 on SQL Server 2008, where merge replication is running

I have a SQL Server 2008 and I should install Service Pack 3 for it. On my server there are several databases replicated, and mobile devices sync data via merge replication. Can problems occur, if I ...
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1answer
2k views

Why I cannot let EXPLAIN update statements?

I can imagine that it's actually more important to explain SELECT statements, but I wonder why there's no possibility to use EXPLAIN on UPDATEs/INSERTs. I may use a WHERE-statement in an UPDATE where ...
1
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1answer
51 views

Set bit in Table A if values are present in Table B

I have two tables, Containing up to ~10 million entries. TableA which has 3 columns: IDA (bigint), IDB (int) and CHK (bit). (IDA, IDB) is the primary key. TableB which has 2 columns: IDA (bigint), ...
1
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1answer
108 views

Improve performance on concurrent UPDATEs for a timestamp column in Postgres

I am using a timestamp column called updated_at for cache invalidation. More information on this particular technique here. The queries all have the same format UPDATE "managers" SET "updated_at" = ...
1
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1answer
5k views

MYSQL - UPDATING multiple rows with different values in one query (for dummies)

I am trying to understand how to UPDATE multiple rows with different values and I just don't get it. The solution is everywhere but to me it looks difficult to understand. For instance, two updates ...
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1answer
98 views

Create constraint for stopping mass update to a table

I want to create a constraint so that if more than 5 rows in a table are getting updated with an UPDATE statement it should warn the user / block the query.
1
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1answer
64 views

Is it a good idea to have an index when the column value changes several times over record lifetime?

I have a table where one of the columns represents an object state - let it be State of type int. The State value starts with 1 and changes to 7 with values in between. Over a row lifetime there're ...
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2answers
553 views

Would existing constraints and indexes applied to an old table, apply to a new table renamed like the old one after it's dropped?

everything is in the question. I have a table named tableA on which we have indexes and foreign keys and constraints. I have to modify content in a column called column1. This being a production ...
1
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1answer
2k views

Find last (max) value according to TimeStamp using update method

I have task to find values of integer according to last (max) of timestamp (datetime) value. Because it is so complicated query I am consindering this way to find last value something like this ...
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1answer
133 views

Joins in Update statement in sqlite

CREATE TABLE Table_1 ( Id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , EmailId VARCHAR ) INSERT INTO Table_1 VALUES (1,'raj@gmail.com'); INSERT INTO Table_1 VALUES (3,'test@gmail.com'); ...
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1answer
61 views

Update different columns on different clauses

I have a database table in Postgres 9.3 with the following layout: id SERIAL, col1 INT, col2 INT Whenever a new row is inserted, I will have to update ALL rows col1 and/or col2 in different cases ...
1
vote
1answer
106 views

How to support multiple updates in this trigger?

Below is the code of a trigger, basically it calls a function in case the record that is being updated does not have other row associated by it's Id in another table. In a multiple row update this ...
1
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2answers
78 views

Oracle tables partition related

Here is my doubt. Is it possible to apply a partition to one table depending in the partitions values of another one? Why I am asking? I have one table where information headers are persisted, and ...
1
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1answer
415 views

Free space from image column after update

I'm doing some cleanup on one of our database for development purposes on a test server. There are a couple of tables with one IMAGE column. Both tables take roughly 50Gb of space, being the image ...
1
vote
1answer
119 views

How to do two actions in conditional UPDATE?

In a query as SET @x = 1 UPDATE table1 SET col2 = IF(col1 = 'y', @x:=0, @x:=@x+1) Every time reaching the value of y in col1, I want to SET the @x:=@x+1 and after that reset the x to 0. In other ...
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1answer
2k views

UPDATE a column by COUNT of another table

It might be a naive question, but what is the difference of these two queries and which is preferred? UPDATE table1, (SELECT id,COUNT(*) idcount FROM table2 GROUP BY id) AS B SET table1.Freq = ...
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1answer
265 views

How to UPDATE a column by COUNT of FK from another table?

How to extend this query for the entire table, to update all ids? UPDATE table1 SET number=( SELECT COUNT(*) FROM table2 where id=1 ) WHERE id=1 id is the PRIMARY KEY in table1 and FK in table2. ...
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1answer
396 views

Mysql update different fileds set depend on condition

I have two tables "a" : CREATE TABLE `a` ( `id` int(11) NOT NULL AUTO_INCREMENT, `i1` int(11) DEFAULT NULL, `i2` int(11) DEFAULT NULL, `ib` int(11) DEFAULT NULL, KEY `id` (`id`) ) ...
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1answer
886 views

How should I update ID field values for all records based on previous values?

I need a SQL query that can update ID fields for all records in a table from their previous values to a new value based on that previous value. For example, if the ID is 1, I want to change it to ...
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1answer
46 views

PostgreSQL, UPDATE CASE statement uses huge amount of space

I am running a CASE statement on one of my tables and it consumes a huge amount of hard drive space that is never freed up even when i run VACUUM ANALYZE. Autovacuum is ON as well. I am using ...
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1answer
20 views

Mysql update adding subquery field value to field

I want to update a field adding it the value of a subquery field. I'm trying this: UPDATE table a SET a.field=(a.field+b.subfield) INNER JOIN (SELECT subid, subfield FROM subtable WHERE ..... ) AS ...
1
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1answer
37 views

Does a database update force index rebuild regardless of updated field?

With MySQL (InnoDB), I understand that having indexes slow down UPDATE queries. I would like to know if this happens regardless of what fields are updated. For example, if I have a table with 20 ...