Category: SQL
- SQL
- May 4, 2024
Understanding Bitmap Index in Oracle database
BITMAP index are different from B-TREE index in the manner they store data. • B-TREE index stores data in tree…
- SQL
- April 14, 2024
Understanding Materialized View ON PREBUILT TABLE
The “ON PREBUILT TABLE” clause is used when you have already created a replicated table using “CTAS” and now want…
- SQL
- April 14, 2024
Understanding DML Statements on a SQL Join View
A join view is a view based on a join. Special considerations apply when you issue a DML(INSERT, UPDATE, or…
- SQL
- April 3, 2024
Understanding Oracle SYS_CONTEXT
The SYS_CONTEXT function is used in both SQL & PL/SQL to return information about the Oracle environment that you’re working…
- SQL
- February 23, 2024
Understanding Oracle External Tables
External tables are read-only tables that allow Oracle to query data that is stored outside the database in flat files….
- SQL
- October 17, 2022
Understanding Join Methods In Oracle Database 19c
A join method is the mechanism for joining two row sources. Depending on the statistics, the optimizer chooses the method…
- SQL
- September 18, 2022
Understanding Clustering In Oracle Database
Clustering is a method of storing tables that are intimately related and often joined together into the same area on…
- SQL
- May 18, 2022
Understanding RealTime Materialized View In Oracle Database 19c
In earlier Oracle version, QUERY REWRITE feature used to stop working as soon as the materialized view become STALE, unless…
- SQL
- July 4, 2021
Understanding Materialized View Query Rewrite
When base tables contain large amount of data, it is expensive and time-consuming to compute the required aggregates or to…