Re: How to read query plan - Mailing list pgsql-performance

From Miroslav Šulc
Subject Re: How to read query plan
Date
Msg-id 4235BCE8.1090705@startnet.cz
Whole thread Raw
In response to Re: How to read query plan  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: How to read query plan
List pgsql-performance
Tom Lane wrote:

>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.
>
>
I'll try to change the data type to bool but the problem I stand in
front of is that the code expects that SELECTs return 'Y' or 'N' but
what I have found out till now is that PostgreSQL returns 't' or 'f' for
bool data. I think about some solution but they use CPU :-(

>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.
>
>
I'll try that. It seems it could work.

>            regards, tom lane
>
>
Miroslav

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