MIN/MAX not be converted to use an index if the query WHERE clause contains
any volatile functions or subplans.
I had originally feared that the conversion might alter the behavior of such a
query with respect to a volatile function. Well, so it might, but only in the
sense that the function would get evaluated at a subset of the table rows
rather than all of them --- and we have never made any such guarantee anyway.
(For instance, we don't refuse to use an index for an ordinary non-aggregate
query when one of the non-indexable filter conditions contains a volatile
function.)
The prohibition against subplans was because of worry that that case wasn't
adequately tested, which it wasn't, but it turns out to be possible to make
8.1 fail anyway:
regression=# select o.ten, (select max(unique2) from tenk1 i where ten = o.ten
or ten = (select f1 from int4_tbl limit 1)) from tenk1 o;
ERROR: direct correlated subquery unsupported as initplan
This is due to bogus code in SS_make_initplan_from_plan (it's an initplan,
ergo it can't have any parParams). Having fixed that, we might as well allow
subplans as well as initplans.
be exported on Linux and Darwin. We already did this on Windows but
that's not enough, as evidenced by the fact that libecpg had an unexpected
dependency on one such symbol. We should try to do it on more platforms.
Fix ecpg's oversight, and bump libpq's major .so version number to reflect
the unwanted but nonetheless real ABI break.
cases. This was not needed in the existing uses within selfuncs.c, but if
we're gonna export it for general use, the extra generality seems helpful.
Motivated by looking at ltree example.
> >> >> > 1) named parameters additionally to args[]
> >> >> > 2) return composite-types from plpython as dictionary
> >> >> > 3) return result-set from plpython as list, iterator or generator
1) named parameters additionally to args[]
2) return composite-types from plpython as dictionary
3) return result-set from plpython as list, iterator or generator
Hannu Krosing
Sven Suursoho
In the SSL code in libpq it does some processing with DH parameters:
SSL_CTX_set_tmp_dh_callback()
This function is marked as server use only[1], the client always uses
the DH parameters in the server, so all the code in the client dealing
with the DH parameters is useless. This patch removes it.
It's not clear why the code was added in the first place, it's been
there almost since the beginning[2]. At the time there was a suggestion
of merging the front-end and backend SSL code, but looking at the
changes since, that seems unlikely.
As a further example, the s_server program allows you to specify DH
params, but s_client doesn't. In the GnuTLS documentation under
gnutls_dh_params_generate2() it says[3]:
Also note that the DH parameters are only useful to servers. Since
clients use the parameters sent by the server, it's of no use to call
this in client side.
shutdown, or when requested by a backend:
It changes so the file is only written once every 5 minutes (changeable
of course, I just picked something) instead of once every half second.
It's still written when the stats collector shuts down, just as before.
And it is now also written on backend request. A backend requests a
rewrite by simply sending a special stats message. It operates on the
assumption that the backends aren't actually going to read the
statistics file very often, compared to how frequent it's written today.
Magnus Hagander
tracks index pages, not free space on pages):
1/ Index free bytes set to NULL
2/ Comment added to the README briefly mentioning the index business
3/ Columns reordered more logically
4/ 'Blockid' column removed
5/ Free bytes column renamed to just 'bytes' instead of 'blockfreebytes'
Mark Kirkwood
set to the large object context ("fscxt"), as this is inevitably a source of
transaction-duration memory leaks. Not sure why we'd not noticed it before;
maybe people weren't touching a whole lot of LOs in the same transaction
before the 8.1 pg_dump changes. Per report from Wayne Conrad.
Backpatched as far as 8.1, but the problem doubtless goes all the way back.
I'm disinclined to spend the time to try to verify that the older branches
would still work if patched, seeing that this code was significantly modified
for 8.0 and again for 8.1, and that we don't have any trouble reports before
8.1. (Maybe the leaks were smaller before?)
thereby saving a visit to the metapage in most index searches/updates.
This wouldn't actually save any I/O (since in the old regime the metapage
generally stayed in cache anyway), but it does provide a useful decrease
in bufmgr traffic in high-contention scenarios. Per my recent proposal.
implied by the predicate of a partial index being used to scan a table.
However, this optimization is unsafe in an UPDATE, DELETE, or SELECT FOR
UPDATE query, because the quals need to be rechecked by EvalPlanQual if
there's an update conflict. Per example from Jean-Samuel Reynaud.
Bruce Momjian
Tom Lane