Hello, I'm KiWong. recently I'm looking for a sqlite update method using something.
so I found the rbu extension. (https://www.sqlite.org/rbu.html) and tested that diff two sqlite3 dbs with rbu option. but I have a problem of big diff size. this db has the BLOB Data in one column and bit level data. found the rbu diff function in 'sqldiff.c' file and i knew that this function will do byte level diff method. therefore, I want to use a RBU custom delta format and found the below. To use a custom delta format, the RBU application must register a user-defined SQL function named "rbu_delta" before beginning to process the update. *rbu_delta()* will be invoked with *two arguments* - the original value stored in the target table column and the delta value provided as part of the RBU update. It should return the result of applying the delta to the original value. To use the custom delta function, the character of the rbu_control value corresponding to the target column to update must be set to 'd' instead of 'x'. Then, instead of updating the target table with the value stored in the corresponding data_% column, RBU invokes the user-defined SQL function "rbu_delta()" and the store in the target table column. but I don't understand about this exactly. Please let me know how can I make a custom delta format and function, update with rbu application in Lib. some example or something.
