Difference between Column store and Row store

Column Store vs Row Store

Row Store

Here the table records are stored in a sequence of rows. The first record goes into the first row, the next one in the second row and so on. The whole row is stored in contagious memory locations. It has the row based in-memory relational data engine that is optimized for high performance of write operations. Basically data is written using this row engine. Tables in the row based store are written at start up time.

Advantages-

• When the appliation needs to only process a single record at one time then at that case we use row store engine.
• If application needs to access the whole record then it's advantageous. If there is no aggregation required then row store is beneficial.

Disadvantage-

• In case of analytic applications where aggregation is used and fast search processing is required, all the data in the row has to be read even if the requirement is just a few columns.

Column Store

It stores the table records in a sequence of columns, that is, the entries of the columns are stored in contagious memory locations. It has column based in-memory relational data engine parts of which originates from TREX (Text Retrieval and Extraction). Basically, data is read using this column engine.It takes the help of Logger to store, save and reference all the data committed in the SAP HANA database.

Advantages-

• SAP HANA is particularly optimized for this column store. In this case the tables can either be loaded at the time of start up or on demand.
• Data access is faster in this case with a significant increase of speed in data queries.
• Columnar data storage allows highly efficient storage and has better parallel processing as well.

This table explains some basic differences between SAP HANA Column Store and SAP HANA Row Store.