InfiniDB uses Extent Maps to retrieve data. Data is stored in extents and each extent is a logical block of space that holds the same number of rows.
The Extent Map catalogs all extents and their corresponding blocks. The Extent Map also maintains minimum and maximum values for a column’s data within an extent.
The Extent Map lets InfiniDB to retrieve only
the blocks needed to satisfy a query. There is another benefit – that of logical range partitioning. This is accomplished via the minimum and maximum values for each extent that are contained within the Extent Map. Extent elimination is first accomplished in InfiniDB via the column-oriented architecture (only needed columns are scanned), but the process is [Read more...]