Il 04/08/2018 07:07, Abramo Bagnara ha scritto: > Il 03/08/2018 23:53, Abroży Nieprzełoży ha scritto: >> -- One table with whole files >> CREATE TABLE content( >> id INTEGER PRIMARY KEY, >> data BLOB NOT NULL >> ); >> -- And second table with line boundaries >> CREATE TABLE lines( >> id INTEGER NOT NULL REFERENCES content(id), >> line_no INTEGER NOT NULL, >> bytes_from INTEGER NOT NULL, >> bytes_to INTEGER NOT NULL, >> PRIMARY KEY(id, line_num) >> ) WITHOUT ROWID; >> -- Use Incremental BLOB I/O https://www.sqlite.org/c3ref/blob_open.html > > Incremental BLOB I/O is faster than using substr(data, start, len) in a > SELECT?
Someone familiar with implementation of BLOB I/O and sqlite VM can answer to that? I'd guess that *if* there is a difference it is greater with bigger blobs, but it is also possible there is not any sensible difference if substr act similarly to sqlite3_blob_read. But my uninformed guesses are definitely not relevant, until an aware Samaritan will come to clarify that ;-) -- Abramo Bagnara BUGSENG srl - http://bugseng.com mailto:abramo.bagn...@bugseng.com _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
