Why is “depesz” between “de luca” and “de vil”?

Every so often someone asks why sorting behaves irrational. Like here:

$ SELECT string FROM test ORDER BY string;
 de luca
 de vil
(6 ROWS)

Why aren't “de luca" and “de vil" together?

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Waiting for 9.1 – KNNGIST

On 4th of December, Tom Lane committed really cool patch:

KNNGIST, otherwise known as order-by-operator support for GIST.

This commit represents a rather heavily editorialized version of
Teodor's builtin_knngist_itself-0.8.2 and builtin_knngist_proc-0.8.1
patches.  I redid the opclass API to add a separate Distance method
instead of turning the Consistent method into an illogical mess,
fixed some bit-rot in the rbtree interfaces, and generally worked over
the code style and comments.
There's still no non-code documentation to speak of, but I'll work on
that separately.  Some contrib-module changes are also yet to come
(right now, point <-> point is the only KNN-ified operator).
Teodor Sigaev and Tom Lane

Continue reading Waiting for 9.1 – KNNGIST