Data Definition Language; defining database structures but not their contents.

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12
votes
2answers
6k views

Best way to populate a new column in a large table?

We have a 2.2 GB table in Postgres with 7,801,611 rows in it. We are adding a uuid/guid column to it and I am wondering what the best way to populate that column is (as we want to add a NOT NULL ...
12
votes
3answers
11k views

Script out Oracle DDL in an automated fashion

Oracle SQL Developer is able to export DDL through Tools -> Database Export... This works very well, but requires manual intervention. I know of DBMS_METADATA.get_ddl(), but have found that the ...
10
votes
1answer
5k views

How to use transactions with SQL Server DDL?

I have a login table into which all inserts are done by a single stored procedure. CREATE TABLE dbo.LogTable( LogRefnr int IDENTITY(1, 1) NOT NULL, LogQuery varchar(255) NOT NULL, LogTime ...
1
vote
1answer
2k views

How to generate create table script without primary and foreign key in Oracle

I have lots of schemas and tables. I want to generate create script of all of my tables. I am using below statement and it is working pretty well. SELECT ...
2
votes
3answers
4k views

Query to compare the structure of two tables in MySQL

To automate the backup process of one of my MySQL databases, I would like to compare the structure of two tables (current version vs old version). Can you think of a query that can compare two ...
7
votes
2answers
3k views

Why is truncate DDL?

I have an interview question, which was asked during my interview. I answered the question, but interviewer was not so convinced with my answer. So, anyone please correct me with my understanding ? ...
5
votes
1answer
16k views

How can I import the contents of an Oracle database into Visio to create an Entity Relationship Diagram?

I have an Oracle database, and I would like to create an ERD in Visio 2007 Pro. I have so far looked at DBMS_METADATA.GET_DDL commands to generate DDL. I know that I can import an Access DB into ...
5
votes
2answers
1k views

SQL Server (2012) non-blocking DDL?

I'm not very experienced with SQL Server, so maybe I'm missing something My situation is as follows: Session 1 runs a CREATE TABLE (or other CREATE statements) with autocommit off and the CREATE is ...
3
votes
1answer
70 views

Drop primary key without dropping an index

Is it possible to drop primary key constraint on a table without dropping the index? I have a situation when I want to remove the PRIMARY KEY to get rid of the NOT NULL constraints and set it to ...
3
votes
1answer
5k views

How to create a partitioned table based on date?

I'm trying to create a partitioned table where partitioning is determined by OrderDate. I'm trying to create a clustered index on OrderDate and a nonclustered primary key on OrderID. But I get an ...
1
vote
2answers
55 views

Speed up creation of Postgres partial index

I am trying to create partial indexes for a large (1.2TB), static table in Postgres 9.4. My data is completely static, so I am able to insert all data, then create all indexes. In this 1.2TB table, ...
1
vote
1answer
53 views

Change column without interrupting service

We need to change the data type of a column in a large table (~1.7 GiB) from VARCHAR(1024) to VARCHAR(512) in order to be able to create a secondary index over two columns. We're using MySQL 5.6 with ...