Questions tagged [alter-table]
SQL statement used to alter an existing table object.
346
questions
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17
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Oracle: why does this DDL yield a different result in production (reordering of columns)?
Problem description
This week we had an issue in production, where an SQL script that was executed ended up with a different result than what we had tested before locally, in Docker and on our ...
- 173
2
votes
0
answers
33
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How to change data type of PK for very min to no maintenance while performing this action
We had issue on our prod server for one of the tables approx 500 M rows and one of the column int has maxed out its length limit. So probable suggestion from dev team was to change data type of that ...
- 723
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votes
1
answer
37
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ALTER TABLE … ADD COLUMN on a small table takes forever, pg_stat_activity doesn't show any queries on this table
So this is the query that hangs forever:
ALTER TABLE tasks
ADD COLUMN in_progress BOOLEAN NOT NULL DEFAULT FALSE;
The table tasks has less than 20,000 rows and is queried once every 5 minutes or so.
...
- 105
3
votes
1
answer
264
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Is it safe to use default value with not null when adding a new column?
We have a Rails app powered by Postgresql v11.4 where I want to add a new column with a default value and a not null constraint like below:
ALTER TABLE "blogs" ADD "published" ...
- 235
1
vote
1
answer
28
views
Adding a column to a table then updating the table
I have a code that looks something like this
declare @query = '
Alter Table Temp
Add NewColumn int
update Temp
set NewColumn = 100'
exec (@query)
It will give error NewColumn does not ...
1
vote
0
answers
19
views
Data in one or more tables corrupt after recovering tables with alter table discard/import tablespace
I accidentally dropped my schema and had to recover all the tables per the steps in this post; Recover schema and the data in it from accidentally deleted schema
However, I notice that all of the ...
- 11
0
votes
1
answer
66
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What is the standard SQL way to rename a column?
So far I've seen ALTER TABLE RENAME, ALTER TABLE CHANGE and ALTER TABLE MODIFY.
What I'm trying to achieve is something like ALTER TABLE my_table RENAME col_old_name TO col_new_name, which can be a ...
- 125
0
votes
1
answer
79
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Mysql Duplicate entry error during new column addition on production database
I have a MySQL table that has 95929357 records, below is the table schema for the same
CREATE TABLE `Friends` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`createdTime` datetime DEFAULT NULL,
`...
- 113
0
votes
0
answers
47
views
Change Column size of a table
We have a mysql 5.6 cluster, 1 master 5 slaves.
Requirements:- We have to modify the size of a column varchar from 20 to 35 for 2 databases.
What is the best approach for doing this accross the ...
0
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0
answers
27
views
Adding new column to clustered column store indexed table
I designing clustered column store indexed fact tables.
Later on many new columns might be added to these currently ~90 columns tables.
How adding new nullable column is affected by the size (number ...
- 266
1
vote
2
answers
314
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Postgresql explain alter table add column doesn't work
I'm using Postgresql 12 (AWS RDS) and pgAdmin4.
While the following statement works
explain select * from table "Commands";
The next one
explain alter table "Commands" drop column &...
- 113
0
votes
1
answer
268
views
Data too long for column when to alter column definition
The column definition is as below:
`code` varchar(15) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL
I want to alter another table(option)'s code field as same definition:
ALTER TABLE `...
- 126
1
vote
1
answer
27
views
Altering mysql database column causes error in another column
First of all sorry everybody if this question sounds too basic.
I have a Wordpress database and a table wp_comments.
In this table, I have two DATETIME fields, whose default value is 0000-00-00 00:00:...
0
votes
1
answer
88
views
Adding Virtual Column after column x is very slow
In our environment, we usually add and drop generated columns every now and then. There is a very large table in the database with more than 3 million rows and adding/removing column was extremely ...
- 195
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0
answers
62
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Creating a foreign key on an empty MySQL InnoDB table takes a very long time
I have created a table called asset_versions:
CREATE TABLE "asset_versions" (
"asset_id" int NOT NULL,
"version" varchar(50) NOT NULL,
"created_at" ...
- 101
1
vote
1
answer
205
views
Alter Table Drop Column INPLACE NoLock - until which point is the column being dropped accessible?
I am trying to run MySQL Alter INPLACE command to drop few columns from a very large 90GB table. While the Alter is running I am able to run the Select statement on the same table to ensure that the ...
- 195
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votes
0
answers
75
views
Add new column and do conditional incremental insert in PostgreSQL
I am new to Postgres, I have a table where I need to add a new column and have to insert incremental values with some filter or you can say condition.
My existing table-
and I want to update it to ...
- 109
1
vote
1
answer
230
views
Why can't I use ALTER to set the default on a column?
Long story short, I have a table with a TIMESTAMP column where I want to make the default CURRENT_TIMESTAMP (default currently is 1971-01-01 00:00:00).
This is part of a WordPress plugin, and so ...
- 61
0
votes
1
answer
94
views
ALTER TABLE statements not replicating in all tested scenarios - MariaDB
Summary
Tech: mariadb 10.3
Issue: some attempts to ALTER TABLE to change engine is not replicating.
Scenarios tested:
command line PHP script running ALTER statements using PDO - did not replicate
...
- 101
1
vote
2
answers
153
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How to rename a column name which has been created by a math function in mysql? Using ALTER TABLE is giving ERROR: 1064 (42000)
INPUT:
CREATE TABLE dist
-> SELECT ST_DISTANCE(POINT(x1,y1),POINT(x2,y2))
-> FROM config;
OUTPUT:
+------------------------------------------+
| ST_DISTANCE(POINT(x1,y1) , POINT(x2,y2)) |
+-----...
- 13
1
vote
1
answer
142
views
Alter table generated text column to normal text column
If I have a table with a generated text column, how do I alter the column to remove the generation expression to get a normal, not-generated text type? Here's the schema:
CREATE TABLE product_history (...
- 149
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0
answers
88
views
Update table column without losing data when releasing a new version of software
I just linked my application with a database using sqlite. Everything worked fine. And I realeased a version of my app.
So I find myself in need of changing a table attribute type.
The sql statement I ...
- 101
0
votes
1
answer
75
views
Alter a table column based on type
I am converting "timestamps without timezone" columns to "timestamps with timezone" on a number of tables. These are large tables and I am going to use batching and other ...
- 293
2
votes
1
answer
694
views
Convert a postgres GENERATED column to a regular non-generated column (in place without DROP)
I'm using postgres 13.3, and I already have an existing table with a GENERATED column such as:
CREATE TABLE test_table (
id uuid NOT NULL DEFAULT uuid_generate_v4(),
the_column_to_alter bool ...
- 223
0
votes
2
answers
78
views
Changing nvarchar (4000) to nvarchar(500)
I have a performance issue with nvarchar(4000). I want to alter the table as per the statement below:
BEGIN declare @length as int
SELECT @length = MAX(LEN([SourceId]))
from [dbo].[table]
if @...
- 1
1
vote
1
answer
1k
views
Make ALTER TABLE wait for lock without blocking anything else
Lots of PostgreSQL ALTER TABLE commands, like adding a new column with a default value, have clever optimisations in the latest versions of PostgreSQL that allow them to execute basically instantly, ...
- 956
2
votes
2
answers
165
views
Convert postgres varchar[] to text[] without downtime
As I discovered in researching this question, converting a column from varchar(100)[] to text[] requires a table rewrite and rebuilding indexes.
Is there a way to manage this conversion without the ...
- 243
3
votes
1
answer
293
views
Postgres varchar(100)[] -> text[] column conversion
I need to change a column type from varchar(100)[] to text[]. The table has >100M rows and heavy write load, so I'd like to avoid taking an access exclusive lock and rewriting the index. I saw in ...
- 243
0
votes
3
answers
147
views
Supplying root password to MySQL V8 sort of fails
On Ubuntu 20.04 I have installed MySQL V8.0.25. But I kind of fail to apply a (valid) root password. The apt-get process for installing mysql-server did not ask for a root password.
And I cannot enter ...
- 101
0
votes
1
answer
112
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How to alter column to make it primary key when one already exists mysql8?
id | bigint unsigned | NO | PRI | NULL | auto_increment |
| title | varchar(255) | NO | | NULL | |
| category | varchar(255) | NO | | NULL |...
0
votes
2
answers
198
views
Why is MySQL InnoDB table copied despite using ALGORITHM=INPLACE for ALTER TABLE
I run an ALTER STATEMENT on an InnoDB table on a MySQL server version 5.7 that:
drop some foreign key constraints
drop some indexes (non unique)
add some columns (without index or foreign key ...
- 103
1
vote
1
answer
45
views
Significant performance differences executing alter and grant statements between users with same permissions
I am experiencing significant performances differences between users with the same permissions when executing alter and grant statements.
I have an automated build system that runs a series of SQL ...
- 111
1
vote
5
answers
256
views
Why can't you add an Identity to an existing colum in SQL Server?
What is so special about an Identity column?
I am pretty sure there is a valid reason, but I'm trying to get a better understanding of SQL.
So what is so special about an Identity column that this can'...
- 333
1
vote
1
answer
54
views
Suppressing SELECT output before \gexec?
This answer is great for when I needed to reown 150 tables, each with 40 tables, but displays the 6000 rows from SELECT before running the 6000 ALTER statements.
Thus, as stated in the Subject, is ...
- 475
0
votes
1
answer
51
views
Improving remake of primary key performance
I'm using a MySQL 5.7 hosted on AWS that has a table with about 500,000,000 rows and 124GB in size.
I want to drop the existing primary key (id) and create a new composite primary key of 2 columns:
...
- 121
1
vote
1
answer
488
views
Why do my RDS read IOPS drop after a certain period of time?
I am trying to add non-null constraints on several columns in a table with about 70,000,000 rows. Each statement is just ALTER TABLE table_name ALTER COLUMN column_name SET NOT NULL;, and each ...
- 169
0
votes
1
answer
198
views
Change bucket count for Primary Key Nonclustered Hash on existing In-Memory table
I'm on SQL Server 2019 Enterprise edition. I have a table with this definition
CREATE TABLE dbo.MyMemoryTable
(
FirstId int NOT NULL,
SecondId int NOT NULL,
MyCount int NOT NULL,
...
- 1,411
1
vote
2
answers
2k
views
"Alter Table" modify multiple columns vs multiple Alter table single column in INNODB?
I am updating collations of my database tables and columns from utf8bin to utf8mb4_bin.
Engine is INNODB with file per table enabled.
I used a query to generate identify all utf8 columns from ...
- 135
0
votes
2
answers
255
views
How to add generated column to db2 table?
I've got a table with the following:
Columns:
---
URL [nullable, e.g. "https://dba.stackexchange.com/"]
APPFK [nullable, e.g. 654654]
LINKTYPE ["Page", "Link", or "...
- 255
1
vote
1
answer
20
views
Why am I getting an error if I am trying to modify data type? [closed]
I am facing an error when I passed the following syntax in MySQL:
ALTER TABLE store MODIFY (DOB char(40)) ;
I am attaching a screenshot too because then you can see that the column DOB is having all ...
5
votes
1
answer
218
views
Why a dropped index is still there, and does it prevent a table from being altered?
I have a column (named RequestDate) which I need to change from NULL to NOT NULL, but there's a clustered index on that column, so I first need to drop that index.
Originally, the index was created ...
- 341
0
votes
2
answers
347
views
In mysql, how to add a primary key and a composite key to a table so that it forbids duplicate rows, when there are null values within the columns?
In the following table (8 mi rows), every column has Null values. However, there can never be two identical rows (there will be always at least one column with a different value for each row).
How can ...
- 103
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votes
1
answer
264
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How do you change the storage parameters of a already made table (sql developer)?
Summarize the problem
I have been given 6 tables that have all been created already and I was told to change the storage parameters of those tables. the issue I run into is that I can only change ...
- 107
0
votes
1
answer
135
views
alter table alter column causes huge log and data file growth
I have a table with 2.6B rows in it and I need to change a column from Char(1) to Varchar(64). the table is over 300GB with a few indexes. The column in nullable, so the transaction i'm running is:
...
- 203
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vote
2
answers
72
views
Promote MySQL Table Partition to Table
My Google Searching skills were not enough to find a solution to this. If possible, how can I promote a partition on a table to a table on its own?
Let's assume I have part0, part1, and part2. Is ...
- 165
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votes
1
answer
68
views
SQL Server :: how to move country code column to another table?
I have 2 tables:
tbl_Countries: 250 values, with columns like CountryName (Afghanistan), TwoCharCountryCode (AF), ThreeCharCountryCode (AFG).
Like this:
CountryName TwoCharCountryCode ...
- 1,105
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votes
1
answer
115
views
Why is ALTER faster than UPDATE (for full table rewrites)?
Let's create a garbage table..
CREATE TABLE foo
AS SELECT x::text FROM generate_series(1,20e6) AS t(x);
Time: 14077.654 ms (00:14.078)
Now, let's look at boring UPDATE,
UPDATE foo SET x = 'foo';
...
- 56.2k
0
votes
1
answer
37
views
How to insert '1001-01-01 00:00:00' into MariaDB when altering a table?
I created a table in HeidiSQL:
CREATE TABLE `publish_dt` (
`ID` BIGINT(20) NOT NULL AUTO_INCREMENT,
`TS` DATETIME NULL DEFAULT NULL,
`Text` VARCHAR(50) NOT NULL COLLATE 'utf8mb4_unicode_ci'...
- 115
0
votes
1
answer
618
views
Alter column fails due to "hidden" statistic
I'm trying to change a column data type from datetime2 to datetimeoffset. I have db owner permissions.
Whenever I run the query:
alter table dbo.<my-table>
alter column [TimeStamp] ...
- 11
1
vote
1
answer
1k
views
MySQL Store Procedure - Setting AUTO_INCREMENT value
I am in trouble coding a store procedure as shown below
CREATE DEFINER=`dbcomexuser`@`%` PROCEDURE `clearance_imp`(IN CAPIfilename VARCHAR(12))
BEGIN
DECLARE `_rollback` BOOL DEFAULT 0;
DECLARE ...
