Hi PostgreSQL Community, I am learning deeply how tuples are organized and column values are accessed in different databases. As far as undertood postgres does not store all column positions in a tuple (e.g. in header or footer). In contrast MySQL InnoDB stores column lengths in a record header [1]. >From the first glance it seems that a postgres format can have a significant performance penalty when accessing a single column which is located after multiple variable-length columns because searching a column value position in a row requires multiple jumps. And in InnoDB a position of a particular column can be found right after reading a header. I found several related threads in pgsql-hackers archives [2,3] describing significant performance wins in a prototype. Does anyone know why the format is still the same? Perhaps InnoDB and similar formats are not so good, are they? Please respond if you have the clue! [1] https://dev.mysql.com/doc/refman/8.0/en/innodb-row-format.html#innodb-row-format-compact [2] https://www.postgresql.org/message-id/flat/c58979e50702201307w64b12892uf8dfc3d8bf117ec0%40mail.gmail.com [3] https://www.postgresql.org/message-id/flat/87irj16umm.fsf%40enterprisedb.com -- Best regards, Ivan Pavlukhin
