Performance of column order

Egon Sommer <Service@Sommer-Maschinenbau.de> writes:

Should I use length-variable colums like TEXT, BLOB,... alfter length-static colums like INTEGER, BOOLEAN, ...?

There is some marginal advantage to that, but I wouldn't recommend
contorting your application to do it. In particular, AFAIR it only
helps in a row that has no NULLs. (Check the heap_getattr code for
the gory details.)

Is there a advantage to create a separate table for BLOBS and TEXT joining the main table about a primary key?

No ... TOAST more or less does that for you.

regards, tom lane

Egon Sommer wrote:

Hallo!

Do anybody know if the order of the columns in a table has affect
on the performance?

Should I use length-variable colums like TEXT, BLOB,... alfter
length-static colums like INTEGER, BOOLEAN, ...?

It is very slightly faster to have variable length stuff after fixed length
fields.

Is there a advantage to create a separate table for BLOBS and
TEXT joining the main table about a primary key?

Probably, though TOAST stores large stuff in backup tables anyway, so
there is probably little difference.

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