How to view object names in user spool space teradata without asking a DBA
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I have 2 Tables :
T_Customer
T_Address
In T_Customer Table have T_Address Foreign Key.
on Web Page Created form Where Customer can add there Details like First Name, Last Name, Address etc.
When Customer Submit form then Adddress details should insert in T_Address table And T_Address ID goes To T_Customer Table is it possible to Create 2 insert operations on one button click?
Is Joins is possible in this?
A single INSERT statement can only affect one table, albeit that you might have some triggers that in turn affect other tables. However, your question was specifically about an action on one button click. This is very possible, and indeed highly advisable. Simply create yourself a single stored procedure and pass it as parameters all the fields required for both Customer and Address tables.
Then within your Stored procedure you can have two inserts, one to Customers and one to Address. If you have a referential integrity constraint, then you must insert customers before address.
The advantage of this approach, is that all commands within a stored procedure are covered by the same transaction: it all succeeds or all fails, and requires only one round trip to the database, in turn being quicker and using less resources.
I have a simple, single table sqlite3 database file that has exactly one table. There are no keys, foreign or domestic. There are no triggers. I have the following workflow:
If the database file exixts open it.
Start exclusive transaction
Select all rows from the table in order.
Operate on each row.
Delete each operated-on row.
When done, count the number of remaining rows in the table, if 0 then DROP the table then unlink the database file
Commit or Rollback the transaction
The drop-table always fails with the message that the table is locked. I've seen a couple of other posts that suggest that there could be open statement handles or other cruft lying around. Since I am using "sqlite_exec()"s for all of this I do not have any open DB anything except the DB handle itself.
Is drop table not allowed in transactions?
When dropping a table, you get the "table is locked" message when there is still some active cursor on the table, i.e., when you did not finalize a statement (or did not close a query object in whatever language you're using).
I am using a global application user account to access database A. This user account does not have permissions to modify database A's schema (ie, create tables, modify tables, etc). This user also has access to database B, but only views. I need to run SQL to feed data from a view in database B into a table in database A.
In a perfect world, I would be able to use this SQL:
create database_a.mytable as (select * from database_b) with no data
However, the user can't create tables in database A. If I could get the DDL of the select statement then I could log in under my personal account (which doesn't have any access to database B) and run the DDL in database A to create the table.
The only other option is to manually write the SQL, but I don't want to do that, especially since this view I am wanting to copy has many columns of varying data types and sizes.
Edit: I may be getting closer. I just experimented with this:
show (select * from database_b.myview)
However, it generated the DLL of every single table that is used in the view itself, as well as the definition for the view. This doesn't really help me since I just want the schema of the select statement itself. In other words, I need what would be generated if I were to use the create table as statement mentioned above.
Edit for Rob: Perhaps "DDL" was the wrong term to use. Using show view db.myview just shows the definition of the view, not the schema it represents. In my above example of create table as, I show how you can create a table that mimics the schema of a result set returned in a select. It generates a DDL on the back end for creating a table and then executes that DDL to actually create the table. You can then say show table db.newtable and see the new table's DDL. I want to get that DDL directly from a select statement so that I can copy it, log out of the app account, into my personal account, and then execute the DDL to create the table.
This is only to save me the headache of having to type out the DDL manually by hand to save time and reduce typing errors, especially since the source view has so many columns. That said, I think hitting up the DBA or writing some snazzy stored procedure to do dynamic stuff would be a bit over the top for my needs. I think there has to be a way to get the DDL for creating a table schema directly from a select statement.
Generate DDL Statements for objects:
SHOW TABLE {DatabaseB}.{Table1};
SHOW VIEW {DatabaseB}.{View1};
Breakdown of columns in a view:
HELP VIEW {DatabaseB}.{View1};
However, without the ability to create the object in the target database DatabaseA your don't have much leverage. Obviously, if the object already existed INSERT INTO SELECT ... FROM DatabaseB.Table1 or MERGE INTO would be options that you already explored.
Alternative Solution
Would it be possible to have a stored procedure created that dynamically created the table based on the view name that is provided? The global application account would simply need privilege to execute the procedure. Generally the user creating the stored procedure would need the permissions to perform the actions contained within the stored procedure. (You have some additional flexibility with this in Teradata 13.10.)
There are some caveats with this approach. You are attempting to materialize views that could reference anywhere from hundreds to billions of records. These aren't simple 1:1 views that are put on top of the target tables. Trying to determine the required space in the target database to materialize the view will be difficult. Performance can and will vary depending on the complexity of the view and the data volumes. This will not be a fast-path or data block optimized operation.
As a DBA, I would be concerned with this approach being taken on by a global application account without fully understanding the intent. I trust you have an open line of communication with the DBA(s) involved for supporting this system. I'm sure there are reasons for your madness that can't be disclosed here.
Possible Solution - VOLATILE TABLE
Unless the implicit privilege for CREATE TABLE has been revoked from the global application account this solution should work.
Volatile tables do not require perm space. There table definitions persist for the duration of the session and any data inserted into them relies on the spool space of the user who instantiated it.
CREATE VOLATILE TABLE {Global Application UserID}.{TableA_Copy} AS
(
SELECT *
FROM {DatabaseB}.{TableA}
)
WITH NO DATA
NO PRIMARY INDEX
ON COMMIT PRESERVE ROWS;
SHOW TABLE {Global Application UserID}.{TableA_Copy};
I opted to use a Teradata 13.10 feature called NO PRIMARY INDEX. By default, CREATE TABLE AS will take the first column of the SELECT statement and make it the PRIMARY INDEX of the table. This could lead to skewing and perm space issues in your testing depending on the data demographics. You can specify an explicit PRIMARY INDEX on your own as you understand the underlying data. (See the DDL manuals for details on the syntax if you're uncertain.)
The use of ON COMMIT PRESERVE ROWS for the intent of this example is probably extraneous. But in reality if you popped any data into that table for testing this clause would be beneficial in Teradata mode as the data would otherwise be lost immediately after the CREATE TABLE or any other data manipulation was performed against the volatile table.
In oracle 11G, I want to drop a user PERMANENTLY, ie no trace of that user should remain and I should not get "existing object" errors like this - ORA-00955: name is already used by an existing object, when I try to recreate that User with its tables.
Please help me to do this.
Thanks.
EDIT -
Commands to create user with table and columns
CREATE USER Products identified by discounted
GRANT ALL PRIVILEGES TO Products
CREATE TABLE Cars(Brand varchar(25),Model varchar(25))
The above is followed by,
Commands to drop user completely and re-create it completely
DROP USER PRODUCTS CASCADE
CREATE USER Products identified by discounted
GRANT ALL PRIVILEGES TO Products
CREATE TABLE Cars(Brand varchar(25),Model varchar(25))
Causes the exception-
java.sql.SQLSyntaxErrorException: ORA-00955: name is already used by an existing object
You didn't say what user you were logging in as, but I'll assume it's SYS or someone with pretty much godlike privileges.
In your last line, you are creating table CARS in the current schema, not in the products schema. What you probably want is:
CREATE TABLE products.cars(brand varchar2(25), model varchar2(25));
The cars table probably still exists in the current schema from your previous attempt. You can tell if it exists anywhere with this:
SELECT owner, object_name, object_type FROM all_objects WHERE object_name = 'CARS';
As a side note, it's not really a good idea to grant all privileges to a normal user, but I assume this is for testing procedures. Also, it's preferred to use VARCHAR2 instead of VARCHAR.
Your question is way too generic. Based on what I understood, if you use following script, you can drop all objects created by the user -
drop user USERNAME cascade;
Documentation
And for this to execute successfully you should not have an open connection for this user.
I am inserting a large number of records into a SQLite database on Android. To improve insert times, I am considering creating the index on the table after data has been fully added.
My question is, at what point does the database actually build the index against values on the table? Does it happen as soon as I issue the SQL statement (create index index_name on table ...), or can the database defer it until the first query arrives?
Thanks,
Ranjit
It creates the index immediately you issue the create index command. The relevant code is in sqlite3CreateIndex and this will create the index and write it to disk (except for the special case where it's called as part of a database open operation but that's not the case when a user creates an index).