How does the Delta engine efficiently load records from the weather data table filtered by latitude?

The Delta engine optimizes the loading of records by leveraging the Delta log, which contains metadata about the data stored in Delta tables. When a query is made to filter records based on latitude, the Delta engine first consults the Delta log. This log keeps track of the statistics for each column, including the minimum and maximum values for the latitude column.

By scanning the Delta log for these statistics, the engine can quickly determine which files in the storage contain relevant records that meet the filter criteria. This process, known as predicate pushdown, allows the engine to avoid reading and loading unnecessary data, making the query execution more efficient. Instead of scanning all records in the dataset, it only focuses on those files where the latitude values fall within the specified range.

This methodology minimizes I/O operations and enhances performance, especially for large datasets, because it processes only the relevant segments of data that satisfy the filter conditions.