Indexing

Objectives:

  • To know what is index using analogy
  • To differentiate clustered versus non-clustered index
  • To refresh on composite index

So now, we know that indexing plays important role in designing relational database!

Indexing is a way to increase retrieval speed. Anything that took many seconds for searching specific keyword becomes FASTER. It perfectly works for sorted data, and the way it matched the values is thru Binary Search technique.

Common Types of Index

Below are the types that maybe you're not aware that database engine does for you at the back:
  • Non-clustered Index
    • The table data is just a pointer to the original table
    • It doesn't sort the table itself -- it's just like creating virtual table where there, it will sort. 
    • Lastly, it can have more than 1 column in table. 
  • Ex. Manually creating an index to a column (cookbook.topic). Foreign keys that automatically creates index.