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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14
votes
2answers
10k views

Optimizing bulk update performance in PostgreSQL

Using PG 9.1 on Ubuntu 12.04. It currently takes up to 24h for us to run a large set of UPDATE statements on a database, which are of the form: UPDATE table SET field1 = constant1, field2 = ...
2
votes
3answers
1k views

Problem with nested UPDATE queries

I cannot make an update query work. As a first step, the following one works correctly: UPDATE Tab1 SET Tab1.a = '3' WHERE Tab1.id IN ( 123, 456 ); where id is the primary key of Tab1. ...
4
votes
1answer
3k views

How to remove known elements from a JSON[] array in PostgreSQL?

I'm facing an issue regarding using the JSON data type in PostgreSQL. I try to achieve storing a Java model denormalized in the DB. The model features lists of complex objects. Thus, I decided to ...
3
votes
1answer
1k views

Update rank on a large table

I have a mysql table that has now 12 million records and I'm trying to update a column (rank) with the following UPDATE code: SET @r=0; UPDATE records SET rank= @r:= (@r+1) where type = 2 ORDER BY ...
2
votes
3answers
285 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 ...
5
votes
6answers
2k views

Backup very large table

I have to update certain values of a large table (for the sake of a presumed example, it is called 'Resource' and it is over 5M rows) and thus I have to make a backup before performing the changes. We ...
3
votes
3answers
8k 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 ...
3
votes
3answers
1k views

INNER JOIN Giving time out on large database

Getting time out on this script UPDATE uk_data AS ud INNER JOIN uk_pc AS up ON ud.cat10 = up.WardCode SET ud.cat8 = up.Latitude, ud.cat9 = up.Longitude; uk_pc Table ...
1
vote
1answer
24 views

mysql trigger / stored procedure - update another table row by row

I've already, searched and read, many answers about this issue for 3 days, but couldn't get a clear answer on how to do this. this will be a little long, be patient please. First of all, I am trying ...
0
votes
1answer
4k views

How to check which tables in DB (MYSQL) updated in last 1 hour / last 1 minute?

I have to create a xls datafeed for a website and I would like to know which tables are getting affected when I do a manual entry from CMS. If i have installed fresh database and I'm doing first ...
7
votes
5answers
84k views

How to update one table based on another table's values on the fly?

I have a table in the name of ips as below: CREATE TABLE `ips` ( `id` int(10) unsigned NOT NULL DEFAULT '0', `begin_ip_num` int(11) unsigned DEFAULT NULL, `end_ip_num` int(11) unsigned DEFAULT ...
7
votes
2answers
14k views

Update many rows in a table with a single statement?

What is the easiest way to update many rows in a table? I have a csv file that looks like this: |primary_key |value| | 1 | xyz| | 2 | abc| | 3 | def| ... Rows with ...
5
votes
1answer
6k views

UPDATE table based on the same table

I have a table with product descriptions, and each product description has a product_id and a language_id. What I want to do is update all of the fields with a language_id of 2 to be equal to the same ...
2
votes
2answers
25k views

SQL Update column with data from another table

I am working on complicated problem, but I will simplify it to this problem. I have two tables A [ID, column1, column2, column3] B [ID, column1, column2, column3, column4] and i want to update ...
0
votes
1answer
300 views

Slow Postgres updates if OTHER columns are indexed?

Certain updates take far too long on large Postgres tables. Given these conditions: only one column is being updated, and it is non-indexed the column already has data in it for every row due to a ...
4
votes
1answer
696 views

Optimizing concurrent updates in Postgres

I'm running concurrent Postgres queries like this: UPDATE foo SET bar = bar + 1 WHERE baz = 1234 Each query affects the fixed K number of rows, and I can't find a way to enforce the order in which ...
4
votes
1answer
9k views

Oracle: Non key-preserved table should be

I'm getting "ORA-01779: cannot modify a column which maps to a non key-preserved table" when I try to update a join. I've searched around the site and found a lot of advice on what key-preserved ...
3
votes
1answer
7k 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 * ...
3
votes
1answer
2k 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 ...
3
votes
2answers
7k views

GROUP BY two columns

I want to count two columns, but need to get the results of first column in one row. SELECT country, COUNT(*) FROM table1 GROUP BY country, type This query gives me country type COUNT(*) ...
2
votes
2answers
286 views

UPDATE table with another table data

I want to update the table car_check field fencing.(total 40 rows).I also use postgis function. I think it's a little difficult.Any suggestions? The code is the first carid example. UPDATE car_check ...
2
votes
1answer
714 views

Update ranking on table

I have two tables: mysql> desc rank ; +----------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
2
votes
2answers
8k views

Most efficient way to add a serial column to a huge table

What's the fastest way to add a BIGSERIAL column to a huge table (~3 Bil. rows, ~ 174Gb)? EDIT: I want the column to be incremented values for existing rows (NOT NULL). I didn't set a fillfactor ...
1
vote
2answers
543 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: ...
1
vote
2answers
132 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) ...
0
votes
1answer
72 views

Update and Insert Statement taking forever

I have a database with two columns that is called using the following query: SELECT TimesUsed, Word FROM Predictions WHERE (Word LIKE @partialWord) ORDER BY TimesUsed DESC In my application it is ...
0
votes
1answer
63 views

Updating MySQL innodb table based on multiple joins

I have a table with the following (slightly simplified) structure CREATE TABLE `oak_relation` ( `o_id` int(10) unsigned NOT NULL, `k_id` bigint(20) unsigned NOT NULL, `initial` float unsigned NOT ...