SQL Function used to alter an existing table object.

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-3
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1answer
42 views

Will column be overwritten when add column is executed?

ALTER TABLE {abc_in} ADD COLUMN abcd_nid int(10) unsigned NOT NULL default '0' AFTER abcd_in What if column abcd_nid already exists ? Will it be overwritten ? how can I insert new values into column ...
4
votes
3answers
4k views

Quickly change NULL column to NOT NULL

I have a table with millions of rows and a column that allows NULL values. However no row currently has a NULL value for that column (I can verify this fairly quickly with a query). However when I ...
1
vote
3answers
3k views

Convert all ntext columns to nvarchar(max)

I'm trying to create a stored procedure to convert all ntext columns in my database to nvarchar(max). This is the code ALTER PROCEDURE [dbo].[usp_SL_ConvertNtextToNvarchar] AS BEGIN SET NOCOUNT ...
1
vote
1answer
2k views

Removing foreign key when it is not named

I've created a table named 'student' as : create table student( stud_id number primary key, stud_name varchar2(30) not null, branch_id varchar2(4) references branch(branch_id), course_id ...
1
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2answers
1k views

Running out of Transaction Log space during Alter Table

I'm running an alter table, alter column on a table with nearly 30 million rows and SQL Azure fails after approximately 18 minutes saying that The session has been terminated because of excessive ...
2
votes
1answer
342 views

Alter mysql database engine doesn't work from cluster to other

I got into this issue when I tried to alter my database table engine to InnoDB from ndbcluster, It did not work. But When I changed engine from InnoDB to ndbcluster it worked. It did not throw any ...
1
vote
1answer
1k views

How to change a column type from SET to an ENUM

I have a table with a SET column type that need to be changed to ENUM type. Can I do it with a simple ALTER or will this mess up my data? NB: there are no multiple values (a,b,c) in the table.
0
votes
1answer
600 views

H2 ALTER TABLE ADD COLUMN BEFORE/AFTER

According to H2 syntax documentation available here I should be able to execute a query like: ALTER TABLE EMPLOYEE ADD COLUMN SECOND_NAME VARCHAR (124) AFTER FIRST_NAME; However apparently only ...
3
votes
2answers
6k views

Reset IDENTITY value

I have a table with an IDENTITY column. While developing I delete the rows from time to time and add them again. But the IDENTITY values always kept increasing and didn't start from 1 when I added ...
0
votes
1answer
320 views

H2 SELECT NULLABLE or other equivalent to check a column has NOT NULL constraint or not

I would like to check if a column has a NOT NULL constraint in order to start an automated upgrade of the table definition. However in H2 the SQL SELECT NULLABLE FROM TABLE_NAME doesn't return me the ...
2
votes
1answer
1k views

Can a view affect ALTER TABLE commands?

I provide a database system to a number of customers. The database is installed locally on Oracle. We periodically upgrade the database structure (either adding new fields, renaming old fields, ...
2
votes
3answers
6k views

Avoiding “Waiting for table metadata lock” when `ALTER TABLE DROP PARTITION`?

I have some tables that many users need to access to: mysql> show create table v3_cam_date\G *************************** 1. row *************************** Table: v3_cam_date Create Table: ...
1
vote
3answers
290 views

Altering same table across multiple databases

I have multiple databases on the same instance and I am in the process of updating a table schema that must propagate across all the databases. I am not sure I know what the right procedure for this ...
1
vote
2answers
1k views

Modify all tables in a database with a single command

Is there a single or a one line command to modify all tables within a database. I would like to issue this command in every table within a database: ALTER TABLE `table_name` CONVERT TO CHARACTER SET ...
0
votes
0answers
33 views

MySQL: optimal configs / methods for ALTER of large MyISAM table to InnoDB (17gb+) [duplicate]

I have a large MySQL (5.1) MyISAM table (13gb table, 4GB indexes - 40mm+ records) I'm going to be converting this table to InnoDB in a production environment. The DB is on a cloud server with ...
0
votes
1answer
367 views

Modify MySQL foreign key related column without dropping foreign key relation

I need to modify a foreign key related column. When I tried to alter it I got "Error on rename of 'x' to 'y' (errno: 150)" error. So I googled and found foreign key relation is the 'villain'. I ...
2
votes
1answer
5k views

After truncating a single partition its Primary key's index becomes unusable and all inserts/updates into that partition fail

I have a partitioned table: SAMPLE_PARTITIONED_TBL with 60 partitions (no sub-paritions) based on the PERIOD_ID numeric field (Data set: 201001...201212.. and so on). This table has several local ...
2
votes
2answers
2k views

SQL set allowed values for a column

I want to make an ALTER TABLE expression which adds a new column and sets a default value and additionaly defines the allowed values for that column. It's a text column, and allowed should be only ...
3
votes
2answers
4k views

How to make a trigger that will compare input with a value of other table?

I had made two tables with the following fields: TABLE 1: "Bookings" FIELD: "fk_flight_number" FIELD: "date_of_reservation" TABLE 2: "Flights" FIELD: "flight_number" FIELD: ...
7
votes
1answer
13k views

What happens when you modify (reduce) a column's length?

Lets say I have two columns of type NUMBER (without precision, and scale) and VARCHAR(300). I saw that these columns are way too large for my data, so I want to modify them to NUMBER(11) and ...
8
votes
5answers
7k views

Alter table on live production databases

How do most "popular" (MySQL, Postgres...) database system handle altering tables on live production databases (like adding, deleting or changing the type of colums)? I know the correct way is to ...
3
votes
2answers
708 views

Alternate ways to increase column size

I have a database that is in production, and in some instances will have millions of records. It has been requested that we increase the sizes of several columns, which is for the most part pretty ...
2
votes
2answers
5k views

SQL Server : how to drop all constraints on a table in T-SQL

I´d like to drop all constraints on all tables in my database, because I need to change the relationships of many of the tables. Is there any way to do that with T-SQL? I cannot find any solution ...
10
votes
1answer
3k views

How do I swap tables in MySQL?

Suppose, I have a table foo, which contains some statistics that are computed every now and then. It is heavily used by other queries. That's why I want to compute more recent statistics in foo_new ...
3
votes
1answer
2k views

Why does altering a table and adding a foreign key create an extra constaint?

Edit: It was a default constraint as a result of setting a default value when adding the column. The name gave it away when starting with 'DF__'. Anyway, solved it by adding the column and manually ...
0
votes
2answers
1k views

Why won't Oracle alter the size of a column that is used for sub partitioning?

I am trying to resize a varchar2 column, when I get an ORA-14265 error: ORA-14265: data type or length of a table subpartitioning column may not be changed With Oracle providing the unhelpful: ...
5
votes
4answers
16k views

Add a new Column and define its position in a table

I have Table A with 5 columns: TableA -- Name Tel Email Address I want to add a new column (mobile) in between Tel & Email: TableA -- Name Tel Mobile Email Address If I use ALTER TABLE ...
2
votes
1answer
1k views

Default values in SQLite3

When I created the table structure of my SQLite database, I provided a DEFAULT value which is used when no value is provided by the user. Now, because the application code changed, I need to modify ...
1
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1answer
86 views

how to use mysql temporal cache tables

I took this example from a book where visitors_today is the cache table from visitor_stored. The idea is to store all the visitors per day (visitors_stored) using a cache table. Create table ...
5
votes
5answers
2k views

Altering table schema takes too much time

I am using PostgreSQL database. I have a table with millions of rows. I have a varchar column with 2000 size and i want to make it to 4000. I ran the alter table command, but it is taking too much ...
5
votes
1answer
3k views

I need to run VACUUM FULL with no available disk space

I have one table that is taking up close to 90% of hd space on our server. I have decided to drop a few columns to free up space. But I need to return the space to the OS. The problem, though, is ...
1
vote
1answer
786 views

Changing collation type database-wide in MySQL

How do I retroactively update the collation type database wide without dropping and recreating it? I accidentally created a database without specifying UTF8 as the default collation type. I then went ...
3
votes
1answer
1k views

Rotate a table in PostgreSQL

Problem description I need to rotate (with DROP and CREATE) a table which is heavily used by other clients. At present, I have a program which replaces (DROP + CREATE) this table. Sometimes, just ...
2
votes
2answers
1k views

Will an ALTER TABLE ADD COLUMN on a slave break replication?

I need to add a last_modified column to a MyISAM table tbl_items. The crux of this problem is that tbl_items houses several gigabytes of data. Also of note, I am using a master-slave deployment with ...
2
votes
1answer
488 views

Add columns Query With parameters

Hello all I'm having 1 Question with following query syntax ALTER TABLE table_name ADD column_name column-definition; Question is can we use parameters to column_name field like @column_name? ...
3
votes
1answer
938 views

Preventing replication of alter table command to change engine

I am in the process of switching a MySQL table from MyISAM to InnoDB and I do not want the slave to perform the alter table command until I execute it manually. The intention is to have a backup for a ...
1
vote
2answers
257 views

How to recover previous values in Mysql Table?

I have MySQL Innodb table of 14M rows. There was a coloumn called is_disabled which had different values. By mistake I ran the query without the where clause: update url_queue set is_disabled=1 ...
4
votes
2answers
11k views

Why does simple ALTER TABLE command take so long on table with full-text index?

I have a large (~67 million rows) name-value table that has full-text indexing on the value column (DataValue). My question is: If I try to run the following sql command: ALTER TABLE VisitorData ...
0
votes
1answer
150 views

Columns are added in wrong order

I have a encountered strange behaviour adding columns to an existing table. I run those scripts using osql several instances. Let Table a_table have initially three columns A_col, B_col and C_col. ...
3
votes
3answers
8k views

MySQL - fastest way to ALTER TABLE for InnoDB

I have an InnoDB table that I want to alter. The table has ~80M rows, and quit a few indices. I want to change the name of one of the columns and add a few more indices. What is the fastest way to ...
1
vote
1answer
551 views

Can't run Alter Table command due to locks

I'm unable to drop, delete or alter a database in my Local SQL Server instance. I have run sp_Who2 and there don't appear to be any processes using the database apart from a process which gets ...
3
votes
1answer
2k views

Alter table modify column on a huge table containing more than 25 million records

I want to modify a column on a huge table containing more than 25 million records. I am using sybase 12.5.4. I have read through these posts What is the most efficient way to alter a column ...
3
votes
1answer
3k views

Can I rename the values in a MySQL ENUM column in one query?

Suppose I have a Database table with an ENUM('value_one','value_two'). I want to change that to an ENUM('First value','Second value'). I an currently doing that as follows: ALTER TABLE `table` MODIFY ...
3
votes
5answers
1k views

Modifying table structure within a transaction?

In Oracle (and probably elsewhere), executing an ALTER TABLE statement will do an implicit commit on the current transaction. We have a tool (written in Java) that should modify a schema by: adding ...
4
votes
3answers
7k views

How to change the datatype of a column from integer to money?

I am attempting to convert a PostgreSQL table column from integer to money, but I am receiving the error: cannot cast type MyColumn to money I have tried these two statements, but just haven't ...
4
votes
2answers
1k views

Preordering the table by a specified column

I have a table and I am always getting the data by ordering a column. In my case, I order by datenum. However, the selection is so slow because of the ordering. Is it possible to order the table ...
18
votes
3answers
5k views

Adding columns to production tables

What's the best way to add columns to large production tables on SQL Server 2008 R2? According to Microsoft's books online: The changes specified in ALTER TABLE are implemented immediately. If the ...
6
votes
3answers
6k views

ALTER TABLE on a large table with an indexed column

I have a large table with a VARCHAR(20) column, and I need to modify that to become a VARCHAR(50) column. Typically, performing an ALTER TABLE (adding a TINYINT) on this particular table takes about ...
1
vote
1answer
1k views

How can I alter the type of a money-column to decimal in PostgreSQL?

I have a table in PostgreSQL where one column "vat" has type money but I would like to alter it to decimal instead. How can I do it? I tried with: alter table my_table alter column vat type ...