What are the differences
between a clustered
and a non-clustered
?
index
Thursday 19 October 2017
sql server - What are the differences between a clustered and a non-clustered index?
itemprop="text">
itemprop="text"> class="normal">Answer
Clustered
Index
- Only one per
table - Faster to read than non clustered as data is
physically stored in index
order
Non
Clustered Index
- Can be
used many times per table - Quicker for insert and update
operations than a clustered
index
Both types of index
will improve performance when select data with fields that use the index but will slow
down update and insert operations.
Because of
the slower insert and update clustered indexes should be set on a field that is normally
incremental ie Id or Timestamp.
SQL
Server will normally only use an index if its selectivity is above
95%.
Subscribe to:
Post Comments (Atom)
php - file_get_contents shows unexpected output while reading a file
I want to output an inline jpg image as a base64 encoded string, however when I do this : $contents = file_get_contents($filename); print &q...
-
I have an app which needs a login and a registration with SQLite. I have the database and a user can login and register. But i would like th...
-
I would like to use enhanced REP MOVSB (ERMSB) to get a high bandwidth for a custom memcpy . ERMSB was introduced with the Ivy Bridge micro...
-
According to my understanding, and my calculator, cos(90 degrees) equals 0 . In my code, I have a funct...
No comments:
Post a Comment