Types Of OLAP-ROLAP,MOLAP,HOLAP-Advantages and Dis-Advantages

Types Of OLAP-ROLAP,MOLAP,HOLAP

OLAP-

OLAP is a advance technique that are used for data storage in database with multidimensional method, The accessing speed of OLAP is faster that OLTP or operational database. OLAP is basically used for fast saving and accessing data from database with different view of point.

Their are mainly 3 types of OLAP-

1.Relational OLAP(ROLAP)

2.Multi-dimensional OLAP(MOLAP)

3.Hybrid OLAP(HOLAP)

we discuss each type in detail as fallows-

1.Relational OLAP(ROLAP)-

That method is used for data saving and data accessing from database mainly. In ROLAP SQL reporting tool are used for extract data directly from data warehouse. In that method use slice and dice method for data accessing from data warehouse. Most of “where” clause are used in that method. It is more scalable for handling large amount of data. In that handle numerical and textual data. ROLAP application display slower performance as compare other MOLAP tools. That tool is suitable for large or complicated calculations because of query language are used.

Advantages of ROLAP-

1.It can handle large amount of data.

Dis-Advantages of ROLAP-

1.Performance can slow.

2.Limited by SQL functionality.

2.Multi-Dimensional OLAP(MOLAP)-

It is a advanced technique in OLAP. In that type data can be saved in database in the from of multi-dimensional cubes with array based structure. Because of data saved multidimensional the data will fetch up or access fastly with user requirement as compare ROLAP.

That is the best tool for create analytical report. the dimensions of cubes are rotate with user requirement mainly-this is done by slice and dice technique. MOLAP are used for complex calculation. There are some limitations of MOLAP is they are less scalable(Accuracy) as compare ROALP. MOLAP also handle limited amount of data.

Advantages of MOLAP-

1.Excellent performance.

2.Can perform complex calculations. 

Dis-Advantages of MOLAP-

1.Limited amount of data handled only.

2.Require additional investment.

3.Hybrid OLAP(HOLAP)-

Hybrid OLAP is the combination of ROLAP and MOLAP in single architecture. It is a bridge between traditional technique to advanced technique. Hybrid are used both ROLAP and MOLAP methods fro storing data mining in well manner. It store large data in ROLAP and complex calculations in MOLAP.

Advantages of HOLAP-

1.Better scalable.

2.handle large amount of data and complex calculations. 

Dis-Advantages of MOLAP-

1.As slow as ROLAP when you try to access leaf level data. 

Explanation :

Online Analytical Processing (OLAP) is a crucial technology in data warehousing that enables fast analysis of data from multiple dimensions. It helps organizations perform complex queries, trend analysis, and decision-making efficiently. There are three main types of OLAP systems—ROLAP (Relational OLAP), MOLAP (Multidimensional OLAP), and HOLAP (Hybrid OLAP)—each with distinct architectures and functionalities suited for different analytical needs.

1. ROLAP (Relational OLAP):

ROLAP operates directly on relational databases. It uses relational tables to store data and employs SQL queries to perform analytical operations. Instead of storing pre-aggregated data, ROLAP dynamically computes aggregations at query time. This makes it suitable for handling large datasets because it leverages existing relational database systems. However, query performance can be slower compared to other OLAP types due to real-time computation. ROLAP is ideal for environments where data volumes are high and updates occur frequently.

2. MOLAP (Multidimensional OLAP):

MOLAP stores data in a multidimensional cube structure rather than traditional relational tables. It pre-calculates and stores aggregated data, allowing users to retrieve results quickly. This approach greatly improves query performance and supports complex analytical operations such as slice, dice, drill-down, and roll-up. However, MOLAP requires more storage space and cube-building time. It is best suited for moderate-sized datasets that need high-speed analysis and frequent reporting.

3. HOLAP (Hybrid OLAP):

HOLAP combines the strengths of both ROLAP and MOLAP. It stores detailed data in relational databases (ROLAP) while keeping aggregated or summarized data in multidimensional cubes (MOLAP). This hybrid approach provides the scalability of ROLAP and the fast query performance of MOLAP. HOLAP systems dynamically decide whether to access data from the cube or the relational database based on query requirements, achieving a balance between performance and storage efficiency.

Read More-

1. What Is Data Warehouse
2. Applications of Data Warehouse, Types Of Data Warehouse
3. Architecture of Data Warehousing
4. Difference Between OLTP And OLAP
5. Python Notes