1. A grid structure for queries on two search keys is a 2-dimensional grid, or array, indexed by values for the search keys. Figure 11.10 (textbook 11.31) shows part of a grid structure for the deposit file.

2. A particular entry in the array contains pointers to all records with the speci ed search key values.

• No special computations need to be done
• Only the right records are accessed
• Can also be used for single search key queries (one column or row)
• Easy to extend to queries on n search keys { construct an n-dimensional array.
• Significant improvement in processing time for multiple-key queries.
• Imposes space overhead.
• Performance overhead on insertion and deletion.