Re: How to read query plan

=?ISO-8859-15?Q?Miroslav_=A6ulc?= <miroslav.sulc@startnet.cz> writes:
> PFC wrote:
>> Instead of a varchar(1) containing 'y' or 'n' you could use a BOOL
>> or an  integer.

> Sure I could. The problem is our project still supports both MySQL and
> PostgreSQL. We used enum('Y','N') in MySQL so there would be a lot of
> changes in the code if we would change to the BOOL data type.

Just FYI, I did a quick search-and-replace on your dump to replace
varchar(1) by "char", which makes the column fixed-width without any
change in the visible data.  This made hardly any difference in the
join speed though :-(.  So that is looking like a dead end.

John's idea about re-joining to the main table to pick up the bulk of
its fields only after joining to the sub-tables might work.

            regards, tom lane