How many buffer pools are available in db2 ?
Ten 32k size buffer pools and fifty 4k size buffer pools (bp0 to bp49)default buffer pools are bp0,bp1,bp2 & bp32 Read more »
Archive for March, 2008
What are the different methods of accessing db2 from tso? How is the connection established between TSO & DB2?
There are three ways in establishing tso/db2 connection 1. SPUFI 2. QMF 3. CATALOG VISIBILITY B. A thread between TSO & DB2 is established while attempting to... Read more »
How many sub queries can you combine together ?
Total 16 queries and sub queries are 15 Read more »
can I alter a table (e.g. adding a column) when other user is selecting some columns or updating some columns from the same table?
yes possible. until the updation or selection is committed db2 table will not be restructured. new column definition will be there but it will not be included until... Read more »
I need to view the number of tables existing under one particular Owner. Is it possible? If so, pl give the SQL query for this ?
The query SELECT * FROM SYSIBM.SYSTABLES WHERE CREATOR = ‘owner id’ This displays the table names with that If you want only the number of tables give... Read more »
What is auditing ?
Recording SQL statements that access a table. Specified at table creation time or through alter. Read more »
When is the authorization check on DB2 objects done - at BIND time or run time ?
At run time. Read more »
How do I create a table MANAGER (EMP-NO, MANAGER) where MANAGER is a foreign key which references to EMP-NO in the same table? Give the exact DDL.
First CREATE MANAGER table with EMP-NO as the primary key. Then ALTER it to define the foreign key. Read more »
What are the disadvantages of using VARCHAR ?
Can lead to high space utilization if most of the values are close to maximum. Positioning of VARCHAR column has to be done carefully as it has performance implications. Relocation... Read more »
When would you prefer to use VARCHAR ?
When a column which contains long text, e.g. remarks, notes, may have in most cases less than 50% of the maximum length. Read more »
What do you mean by NOT NULL WITH DEFAULT ? When will you use it?
This column cannot have nulls and while insertion, if no value is supplied then it will have zeroes, spaces or date/time depending on whether it is numeric, character... Read more »
What is the difference between SYNONYM and ALIAS ?
SYNONYM : is dropped when the table or tablespace is dropped. Synonym is available only to the creator. ALIAS : is retained even if table or tablespace... Read more »
What is a synonym ?
Synonym is an alternate name for a table or view used mainly to hide the leading qualifier of a table or view.. A synonym is accessible only by the creator. Read more »
What is index cardinality ?
The number of distinct values a column or columns contain. Read more »