I am not sure to understand the "format" and why you cannot use the jdbc plugin with some UDF to parse the blob
Some comments below > 1) Is there any documentation / tutorial out there covering this topic? No > 2) Which existing storage plugin might be a good candidate to look at and > learn from? The MongoDB plugin is good for that, But in your case you can probably directly use the JDBC plugin to call SQLite focus on binary format > 3) As SQLite is the underlying storage engine and thus is able to help in > pushed-down selections and joins, can I implement partial pushdown, meaning > just for some fields? > Because SQLite can help with operations on regular SQLite columns, but > SQLite does not understand the binary blobs that represent structural > nested data. So, can I tell Drill, that > only for some parts of the schema pushdown is possible? Can you give an example ? > > 4) If starting from an existing plugin, would you recommend starting from > the JDBC plugin, a file-system/json plugin, or any other one? Since it looks you have to focus on some fields only you can look at https://github.com/apache/drill/tree/master/exec/java-exec/src/main/java/org/apache/drill/exec/store > 5) Do I need to specify the schema fully (i.e. the full nested blob-column > data types?) or is there something like Drill-Data-type: „json“ and Drill > does the inspection? Drill can do the inspection , look at Json/parquet > I would appreciate your advice and best regards, > Thomas
