by Dexter | Jan 6, 2021 | Oracle SQL
Bitmap Indexes are used for indexing columns which have low cardinality. Before we begin understanding about Bitmap indexes, lets revisit the concept of indexes and why we create them. An index in Oracle helps us in fetching data from tables much more efficiently. We...
by Dexter | Jan 6, 2021 | Oracle SQL
In this tutorial, we will learn how to create unique index on a table which prevents duplicate values within the indexed column. We can create unique index on one or more columns and technically, its same as creating a primary key or unique constraint as both serve...
by Dexter | Jan 6, 2021 | Oracle SQL
Function based Indexes are used for ensuring faster retrieval of data for a query which contain a function. Function based index is used by Oracle Server to fetch query results more efficiently and quickly. Instead of creating an index on columns like we do in other...
by Dexter | Jan 6, 2021 | Oracle SQL
Expression based Indexes are used for optimizing the performance of queries which contain an expression. We create an index on column to ensure faster retrieval of data from tables and Expression Based Indexes also ensures optimization of queries for better...
by Dexter | Jan 6, 2021 | Oracle SQL
When we create an Index on more than one columns in a table, then it is known as Compound Index. In real life scenarios, often times we need to use more than one columns in a query and if the table contains a lot of rows, the performance of query will be generally...
by Dexter | Jan 6, 2021 | Oracle SQL
In this tutorial, we will learn about the different dictionary views on Indexes in Oracle database. Indexes are stored in Oracle database as Database Objects. We can get more information about the different indexes present in a user schema by accessing these data...
