If I create a temporary table using # sign:
SELECT * INTO #temp FROM dbo.table
Where is this table located? I can't find this from tempdb.
Those tables are created in your tempDB - but the table name might not be exactly as you defined.
In my case, I get:
#temp______________________________000000000003
Try this:
SELECT * INTO #temp FROM dbo.table
SELECT * FROM tempdb.sys.tables
You should see an entry for that temp table you've just created....
When you declare a temporary table, SQL Sever adds some additional characters on its name in order to provide a unique system name for it and then it stores it in tempDB in the sysobjects table. Even though you can query the temporary table with its logical name, internally is known with the exact name SQL Server has set.
How are you looking for them?
If you do a select you'll get the data.
But the table is only available in the session, just for the user who created it (you can have global temp tables).
They are stored in temp db.
Local temp tables can be created using hash (#) sign prior to table name.
They are visible only in current connection. When connection is dropped its scope ends as well.
It is possible to create and use local temp table with the same name simultaneously in two different connections.
Read More
http://sqlnetcode.blogspot.com/2011/11/there-is-already-object-named-temp-in.html
I suspect this issue rose from the fact that if you don't right click and refresh the 'Temporary Tables' folder, SSMS will not show you the temp table immediately.
Related
Is there any way in DB2 to find temp table from the session ?
I have created a temp table pertaining to session
DECLARE GLOBAL TEMPORARY TABLE SESSION.TEMP_TABLE_NAME
(
COL_1 VARCHAR(11) NOT NULL,
COL_2 VARCHAR(10)
) ON COMMIT PRESERVE ROWS;
When I am trying to create query
select * from sysibm.systables where owner='SESSION' and name='TEMP_TABLE_NAME'
yields 0 rows.
Am I looking at the incorrect table to find temp tables ?
Thanks !
A declared global temporary table ( DGTT) will not appear in the catalog, this is the design - so you will not find a DGTT in sysibm.systables. A DGTT cannot be used by any other program except the one that declares it - it is specific to that session, hence there's no value to having it in the catalogue.
If you are using Db2 for z/OS (v10 or higher), or Db2-LUW, you may need instead, a "CREATED global temporary table" (CGTT) which uses a different syntax create global temporary table ... These are catalogued, but you need relevant permissions to create them.
See the Db2-LUW documentation.
or for Db2 for z/OS here.
Look at the SYSIBMADM.ADMINTEMPTABLES administrative view.
If you want to see all the DGTTs created in your session, then:
SELECT TABNAME
FROM SYSIBMADM.ADMINTEMPTABLES
WHERE TEMPTABTYPE='D'
AND APPLICATION_HANDLE=mon_get_application_handle();
How do I lock a global temporary table in a stored procedure that's getting created and populated by a SELECT INTO statement? For example:
SELECT *
INTO ##TempEmployee
FROM Employee
This stored procedure is executed for generating reports and it's there in every client database (multi-tenant architecture using different DB per client). I do not want data in this global temporary table to be shared between clients when the report is generated concurrently. I don't have a choice but to use global temp table because I use it for generating columns on the fly using PIVOT.
Why not include it inside a transaction block like
begin transaction
SELECT *
INTO ##TempEmployee
FROM Employee
Try this,
WorkDummySQL
create table rr(id integer,name varchar(20))
insert into rr values(1,'aa')
select * from rr
Tempdb
select * into ##ta from WorkDummySQL.dbo.rr
When I run a script in PostgreSQL I usually do the following from psql:
my_database> \i my_script.sql
Where in my_script.sql I may have code like the following:
select a.run_uid, s.object_uid into temp_table from dt.table_run_group as a
inner join dt.table_segment as s on a.group_uid = s.object_uid;
In this particular case, I am only interested in creating temp_table with the results of the query.
Are these results in disk on the server? In memory? Is the table stored permanently?
Temporary tables are stored in RAM until the available memory is used up, at which time they spill onto disk. The relevant setting here is temp_buffers.
Either way, they live for the duration of a session and are dropped at the end automatically.
You can also drop them at the end of a transaction automatically (ON COMMIT DROP) or manually any time.
Temporary table are only visible to the the same user in the same session. Others cannot access it - and also not conflict with it.
Always use CREATE TABLE tbl AS .... The alternative form SELECT ... INTO tbl is discouraged since it conflicts with the INTO clause in plpgsql.
Your query could look like:
CREATE TEMP TABLE tbl AS
SELECT a.run_uid, s.object_uid
FROM dt.table_run_group a
JOIN dt.table_segment s ON a.group_uid = s.object_uid;
SELECT INTO table ... is the same as CREATE TABLE table AS ..., which creates a normal, permanent table.
Are table variables created in memory or in tempdb? Same for
short temp tables?
A temp table will be created in tempdb and you can easily check for it by querying the sysobjects table in tempdb
example
create table #test (Item char(1), TimeSold varchar(20))
select * from tempdb.sys.sysobjects
where name like '#test%'
you should see something with a name like #test_______000000000905 but then with more underscores
If you need to check if a temp table exists then see also How Do You Check If A Temporary Table Exists In SQL Server
The structure of Table variable is also created in tempdb To see the table variable you could do something like this but there is not guarantee that someone didn't sneak in before you when creating his/her table variable. The table variable name will be something like #7BB1235D
declare #v table(id int)
select top 1 * from tempdb.sys.sysobjects
where name like '#%'
and name not like '%[_]%'
order by crdate desc
select * from #v
For more info see here: http://support.microsoft.com/kb/305977
It's been my understanding that, at a minimum, the structure of a table variable is always created in TempDB. Then, as pointed out by SQLMenace, the data may or may not spill over.
Per this Microsoft Knowledge Base Article:
A table variable is not a memory-only
structure. Because a table variable
might hold more data than can fit in
memory, it has to have a place on disk
to store data. Table variables are
created in the tempdb database similar
to temporary tables. If memory is
available, both table variables and
temporary tables are created and
processed while in memory (data
cache).
In MS SQL 2014 was introduced special type of table variables "Memory-Optimized Table Variables". And they don't use tempdb.
See https://msdn.microsoft.com/en-us/library/dn535766.aspx
I need a query to create a table which is the exact replica but with different table name and without any data from the source table using a sql query!
You can try this
SELECT * INTO Table_Copy
FROM Table
where 1=2
It will create a empty table with the same structure.
SQL Server Management Studio
Object Explorer
Connect -> Your server
Databases -> Choose Database
Tables
Right Click Your Table
Script Table as -> Create To -> New Query Editor Window
Jonathan has it (upvoted), and you should probably go with that because it's more portable. I normally use something similar:
SELECT TOP 0 * INTO [New_Table] FROM [Old_Table]
I think this better expresses what you're doing, but I like Jonathan's because 'TOP 0' is SQL Server specific, and so his is more portable.
For MySQL, you can call SHOW CREATE TABLE table_name;
It will display a CREATE TABLE query. Simply change the table name in that query and you're good to go.
http://dev.mysql.com/doc/refman/5.1/en/show-create-table.html
If you use Postgresql:
CREATE TABLE LIKE table_name
http://www.postgresql.org/docs/8.1/static/sql-createtable.html
SELECT * INTO Table_Copy
FROM Table
where 1=2
This worked very well, when i tried to create a replica of the table without any data's.
SELECT * INTO Table_Copy
FROM Table
This will create a replica with the data's too.
This can help you:
CREATE TABLE foo AS SELECT...
Read more here
select * into newtablename from sourcetablename
go
truncate newtablename
go
That will result in an exact copy but it also copies the data at first which you remove with the truncate statement.
create table <new table name> as select * from <old tale name from which you would like to extract data>
It will create a new table with a different name but will copy all existing data from the old table to new table.
in postgres you can use INHERITS or LIKE keyword to make replica of a table(only copies structure of the table)
CREATE TABLE client_new (LIKE client);
or
CREATE TABLE client_new () INHERITS (client)
Use of INHERITS creates a persistent relationship between the new child table and its parent table(s). Schema modifications to the parent(s) normally propagate to children as well, and by default the data of the child table is included in scans of the parent(s).
LIKE clause specifies a table from which the new table automatically copies all column names, their data types, and their not-null constraints.Unlike INHERITS, the new table and original table are completely decoupled after creation is complete. Changes to the original table will not be applied to the new table, and it is not possible to include data of the new table in scans of the original table.