Indexes:
A table has got unique index of which all participating column being foreign keys.
This table has got one more index which also has those foreign keys columns along with other columns of index.
It is perfectly normal as per TLMR.
Thursday, February 18, 2010
Tuesday, February 16, 2010
not in & NOT EXISTS... SUGAR and SUGAR CANE
NOT EXISTS can yield different results from NOT IN.
---------------------------------------------------------------
NOT IN implies that data exists in the column. A predicate testing a
column containing a NULL value will not satisfy the NOT IN condition.
(verified on UDB LUW 8.1)
A null value in a code will satisfy the NOT EXISTS clause in your second
example. This is true even if t2 has a row containing a null value in eid!
---------------------------------------------------------------
NOT IN implies that data exists in the column. A predicate testing a
column containing a NULL value will not satisfy the NOT IN condition.
(verified on UDB LUW 8.1)
A null value in a code will satisfy the NOT EXISTS clause in your second
example. This is true even if t2 has a row containing a null value in eid!
Wednesday, January 27, 2010
Ussse Ful Spices !!!
Find Out matching Columns from tables
SELECT TBNAME FROM SYSIBM.SYSCOLUMNS WHERE NAME = 'val'
Tip:
Adding the schema name/creator name in the select list will be helpful
If you are using DB2 on Unix/Win as a standard use syscat.columns ...
SELECT TBNAME FROM SYSIBM.SYSCOLUMNS WHERE NAME = 'val'
Tip:
Adding the schema name/creator name in the select list will be helpful
If you are using DB2 on Unix/Win as a standard use syscat.columns ...
First Dish in the making....Data base creation
CREATE DATABASE Command - Very Useful recipe..may be eat only when doing Party.. ;)
999 INGREDIENTS
* Authorization
You must have one of the following:
* 9 sysadm
* 9 sysctrl
* Required connection
999 Prepared Ness
This command is not valid on a client.
Instance. 9 To create a database at another (remote) node, you must first attach to that node. 9 A d
The CREATE DATABASE command initializes a new database with an optional user-defined collating sequence,
creates the three initial table spaces,
creates the system tables,
and allocates the recovery log file.
-> When you initialize a new database, you can specify the AUTOCONFIGURE option to <> display and optionally apply the initial values for the buffer pool size, <> database and database manager parameters.
The AUTOCONFIGURE option 9 is not available in a partitioned database environment.
Scope
In a partitioned database environment, this command affects all database partitions that are listed in the db2nodes.cfg file.
The database partition from which this command is issued becomes the catalog database partition for the new database.
Authorization
9
9 Instance. 9 To create a database at another (remote) node, you must first attach to that node. 9 A database connection is temporarily established by this command during processing.
Command syntax
999 INGREDIENTS
* Authorization
You must have one of the following:
* 9 sysadm
* 9 sysctrl
* Required connection
999 Prepared Ness
This command is not valid on a client.
Instance. 9 To create a database at another (remote) node, you must first attach to that node. 9 A d
The CREATE DATABASE command initializes a new database with an optional user-defined collating sequence,
creates the three initial table spaces,
creates the system tables,
and allocates the recovery log file.
-> When you initialize a new database, you can specify the AUTOCONFIGURE option to <> display and optionally apply the initial values for the buffer pool size, <> database and database manager parameters.
The AUTOCONFIGURE option 9 is not available in a partitioned database environment.
Scope
In a partitioned database environment, this command affects all database partitions that are listed in the db2nodes.cfg file.
The database partition from which this command is issued becomes the catalog database partition for the new database.
Authorization
9
9 Instance. 9 To create a database at another (remote) node, you must first attach to that node. 9 A database connection is temporarily established by this command during processing.
Command syntax
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