In a method and system for efficient storage and retrieval of data using Simultaneous Multiple-method (SMm) data compression and data decompression the data in a first processing unit is compressed. A SMm data compression unit determines the type of data compression to use for each range of data, constructs and stores a SMm Index Table for the data, and constructs and stores a Compressed Data Table for the data. The SMm Index Table and the Compressed Data Table may be transferred to a second processing unit, where the SMm Index Table is queried using a key element. A type of data compression to be used is retrieved and a determination is made based on the type of data compression used whether data decompression is required. Data from the SMm Index Table is retrieved if data decompression is not required. Data retrieved from the SMm Index Table is interpreted in order to make a decision based on a logical value of the data. Data from the Compressed Data Table is retrieved if data decompression is required and data decompression is performed if required.