REDSHIFT ALTER TABLE COLUMN SIZE HOW TO

I then executed the second half of the script, to add the constraint back in: ALTER TABLE. Now that the constraint was gone, the original change worked nicely: use I then executed the first half of this script, to drop the constraint: ALTER TABLE. )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON

Not to be deterred, in SQL Server Management Studio I right clicked on the constraint PK_USER_USER_ID, then selected 'Script key as > Drop and Create To > New Query Editor Window': The object 'PK_USER_USER_ID' is dependent on column 'USER_ID'.ĪLTER TABLE ALTER COLUMN USER_ID failed because one or more objects access this column. These commands are primarily governed by database administrators that revolve around four primary commands i.e. ALTER TABLE tablename ALTER COLUMN columnname TYPE newdatatype Example, below command resizes column1 to varchar (100).

REDSHIFT ALTER TABLE COLUMN SIZE HOW TO

This resulted in this error because there was a constraint on the key: Msg 5074, Level 16, State 1, Line 2 There are five basic types of SQL commands, namely: Data Definition Language (DDL): DDL commands are used to create, modify, and remove database objects. How-To Guides / Redshift How to resize a column in Redshift database Use the below command to modify the column width in Redshift. Like autocommit mode and adding the new column, renaming old & new columns, and dropping the old etc.This technique worked really nicely for me.ĪLTER TABLE.

Are you in autocommit mode or are you managing your transaction block when executing? (Run 'END ' as one block)ĭepending on what issue you are encountering there are ways to work around them. To get the size of each table, run the following command on your Redshift cluster: SELECT 'table', size, tblrows FROM SVVTABLEINFO The table column is the table name.

Are there constraints on the column product_price or is it a key? ALTER TABLE locks the table for read and write operations until the transaction enclosing the ALTER TABLE operation completes, unless it's specifically stated in the documentation that you can query data or perform other operations on the table while it is altered.

Does product_price have a default value?.

Does the existing data fit in 18,4? You lost 2 digits before the decimal point - you may need 20,4.

What is the encoding of the column product_price?.

This leads to the following questions / possibilities: END).įor more information about transactions, see Serializable isolation. You can't alter columns within a transaction block (BEGIN. You can't alter columns with UNIQUE, PRIMARY KEY, or FOREIGN KEY. You can't alter columns with default values. You can't decrease the size less than maximum size of existing data.

You can't alter a column with compression encodings BYTEDICT, The default precision, if not specified, is 18. For example, the number 48.2891 has a precision of 6 and a scale of 4. Size of a column defined as a VARCHAR data type. To conserve storage, you can define a table initially with VARCHAR columns with the minimum size needed for your current data requirements. Define a DECIMAL column in a table by specifying a precision and scale: decimal ( precision, scale) precision The total number of significant digits in the whole value: the number of digits on both sides of the decimal point. To replicate this functionality, your application would first need to query the table metadata and then make the decision whether to issue the ADD COLUMN command. I'll use the Redshift documentation on this to show many:ĪLTER COLUMN column_name TYPE new_data_type A clause that changes the There is no Amazon Redshift command equivalent to ADD COLUMN IF NOT EXISTS. There are a number of reasons why this could be failing.

Redshift alter table column size