Doc: remove claim that hash index creation depends on effective_cache_size.

This text was added by commit ff213239c, and not long thereafter obsoleted
by commit 4adc2f72a (which made the test depend on NBuffers instead); but
nobody noticed the need for an update.  Commit 9563d5b5e adds some further
dependency on maintenance_work_mem, but the existing verbiage seems to
cover that with about as much precision as we really want here.  Let's
just take it all out rather than leaving ourselves open to more errors of
omission in future.  (That solution makes this change back-patchable, too.)

Noted by Peter Geoghegan.

Discussion: 

diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
index 745089993be41e851ca42209d3e87696b547e10e..32b424e8f650b3e49f841f7a152897f343262021 100644 (file)
--- a/doc/src/sgml/ref/create_index.sgml
+++ b/doc/src/sgml/ref/create_index.sgml
@@ -568,16 +568,7 @@ Indexes:
    dependent on the setting of .
    Larger values will reduce the time needed for index creation, so long
    as you don't make it larger than the amount of memory really available,
-   which would drive the machine into swapping.  For hash indexes, the
-   value of  is also relevant to
-   index creation time: PostgreSQL will use one
-   of two different hash index creation methods depending on whether the
-   estimated index size is more or less than effective_cache_size.
-   For best results, make sure that this parameter is also set to something
-   reflective of available memory, and be careful that the sum of
-   maintenance_work_mem and effective_cache_size is
-   less than the machine's RAM less whatever space is needed by other
-   programs.
+   which would drive the machine into swapping.