What is a pseudo key? What is its use???
Answers were Sorted based on User's Feedback
Answer / tdguy
If a table in a database either has no natural key or the
natural key is so long that using it as the key would be
inefficient then we need to consider using a pseudokey
instead. Pseudokeys are usually given the same name as the
table they belong to with _id added to the end of the name.
They usually are defined to contain a number and use
autoincrement in mySQL or the equivalent in other versions
of SQL to dynamically allocate a value when new rows are
created.
source: http://www.felgall.com/mysql04.htm
Is This Answer Correct ? | 6 Yes | 0 No |
Answer / guest
it is used in locks the rowhash
best to tell EXPLAIN in this explanation we locks pseudo key
then it start
Is This Answer Correct ? | 0 Yes | 10 No |
what are the default access rights in the teradata?
Explain teradata utilities?
Explain the parallel data extension in teradata?
Can any one please provide me practical example of How to do the performance tuning in Query??
How to view every column and the columns contained in indexes in teradata?
What do you mean by teradata intellicloud?
Which is faster fastload or multiload?
How do you Generate Sequence in Teradata?
How to run the Teradata jobs in unix environment ???
Give the sizes of SMALLINT, BYTEINT and INTEGER.
which join mostly use in realtime?
If Fast Load Script fails and only the error tables are made available to you, then how will you restart?