Keyword search in relational database is a method that has higher relevance in the current world. One very important thing is extracting data from a large database. So it reduces the personal and time consuming works. Data extraction from a large number of sets of database using the relevant keyword based on the users are needed. It is a very interactive and user-friendly. Keyword search enables the user to get information without knowing any database schemas or complex query languages like SQL (Structured Querry Language). Using a keyword in relational database, data extraction will be easier. The user doesn't want to know the query language for searching on the database. Study of keyword search using algorithms such as BANKS, DBXPLORE, DISCOVER, DEINIX in detailed explanation are given for further process. This process continues for future work which selects the one which is best based on the analyses. The main objective of this study about keyword searching in large database is to reduce the memory space and making an efficient retrieval of information; also it reduces the time of the user for retrieving the required data.