ListCells are only 8 bytes instead of 12 (on 4-byte-pointer machines
anyway), it's worth maintaining a separate freelist for 8-byte objects.
Remembering that alloc chunks carry 8 bytes of overhead, this should
reduce the net storage requirement for a long List by about a third.
> FWIW, the section on configuring kernel resources under various
> Unixen[1] doesn't have any documentation for AIX. If someone out there
> knows which knobs need to be tweaked, would they mind sending in a doc
> patch? (Or just specifying what needs to be done, and I'll add the
> SGML.)
After verifying that nobody wound up messing with the kernel
parameters, here's a docs patch...
Chris Browne
the four functions.
> Also, please justify the temp-related changes. I was not aware that we
> had any breakage there.
patch-tmp-schema.txt contains the following bits:
*) Changes pg_namespace_aclmask() so that the superuser is always able
to create objects in the temp namespace.
*) Changes pg_namespace_aclmask() so that if this is a temp namespace,
objects are only allowed to be created in the temp namespace if the
user has TEMP privs on the database. This encompasses all object
creation, not just TEMP tables.
*) InitTempTableNamespace() checks to see if the current user, not the
session user, has access to create a temp namespace.
The first two changes are necessary to support the third change. Now
it's possible to revoke all temp table privs from non-super users and
limiting all creation of temp tables/schemas via a function that's
executed with elevated privs (security definer). Before this change,
it was not possible to have a setuid function to create a temp
table/schema if the session user had no TEMP privs.
patch-area-path.txt contains:
*) Can now determine the area of a closed path.
patch-dfmgr.txt contains:
*) Small tweak to add the library path that's being expanded.
I was using $lib/foo.so and couldn't easily figure out what the error
message, "invalid macro name in dynamic library path" meant without
looking through the source code. With the path in there, at least I
know where to start looking in my config file.
Sean Chittenden
(1) boolean-and and boolean-or aggregates named bool_and and bool_or.
they (SHOULD;-) correspond to standard sql every and some/any aggregates.
they do not have the right name as there is a problem with
the standard and the parser for some/any. Tom also think that
the standard name is misleading because NULL are ignored.
Also add 'every' aggregate.
(2) bitwise integer aggregates named bit_and and bit_or for
int2, int4, int8 and bit types. They are not standard, but I find
them useful. I needed them once.
The patches adds:
- 2 new very short strict functions for boolean aggregates in
src/backed/utils/adt/bool.c,
src/include/utils/builtins.h and src/include/catalog/pg_proc.h
- the new aggregates declared in src/include/catalog/pg_proc.h and
src/include/catalog/pg_aggregate.h
- some documentation and validation about these new aggregates.
Fabien COELHO
extend the GUC variable set".
Plugin modules like the pl<lang> modules needs a way to declare
configuration parameters. The postmaster has no knowledge of such
modules when it reads the postgresql.conf file. Rather than allowing
totally unknown configuration parameters, the concept of a variable
"class" is introduced. Variables that belongs to a declared classes will
create a placeholder value of string type and will not generate an
error. When a module is loaded, it will declare variables for such a
class and make those variables "consume" any placeholders that has been
defined. Finally, the module will generate warnings for unrecognized
placeholders defined for its class.
More detail:
The design is outlined after the suggestions made by Tom Lane and Joe
Conway in this thread:
http://archives.postgresql.org/pgsql-hackers/2004-02/msg00229.php
A new string variable 'custom_variable_classes' is introduced. This
variable is a comma separated string of identifiers. Each identifier
denots a 'class' that will allow its members to be added without error.
This variable must be defined in postmaster.conf.
The lexer (guc_file.l) is changed so that it can accept a qualified name
in the form <ID>.<ID> as the name of a variable. I also changed so that
the 'custom_variable_classes', if found, is added first of all variables
in order to remove the order of declaration issue.
The guc_variables table is made more dynamic. It is originally created
with 20% slack and can grow dynamically. A capacity is introduced to
avoid resizing every time a new variable is added. guc_variables and
num_guc_variables becomes static (hidden).
The GucInfoMain now uses the new function get_guc_variables() and
GetNumConfigOptions instead or using the guc_variables directly.
The find_option() function, when passed a missing name, will check if
the name is qualified. If the name is qualified and if the qualifier
denotes a class included in the 'custom_variable_classes', a placeholder
variable will be created. Such a placeholder will not participate in a
list operation but will otherwise function as a normal string variable.
Define<type>GucVariable() functions will be added, one for each variable
type. They are inteded to be used by add-on modules like the pl<lang>
mappings. Example:
extern void DefineCustomBoolVariable(
const char* name,
const char* short_desc,
const char* long_desc,
bool* valueAddr,
GucContext context,
GucBoolAssignHook assign_hook,
GucShowHook show_hook);
(I created typedefs for the assign-hook and show-hook functions). A call
to these functions will define a new GUC-variable. If a placeholder
exists it will be replaced but it's value will be used in place of the
default value. The valueAddr is assumed ot point at a default value when
the define function is called. The only constraint that is imposed on a
Custom variable is that its name is qualified.
Finally, a function:
void EmittWarningsOnPlacholders(const char* className)
was added. This function should be called when a module has completed
its variable definitions. At that time, no placeholders should remain
for the class that the module uses. If they do, elog(INFO, ...) messages
will be issued to inform the user that unrecognized variables are
present.
Thomas Hallgren
It was necessary to touch in grammar and create a new node to make home
to the new syntax. The command is also supported in E
CPG. Doc updates are attached too. Only superusers can change the owner
of the database. New owners don't need any aditional
privileges.
Euler Taveira de Oliveira
In the past, we used a 'Lispy' linked list implementation: a "list" was
merely a pointer to the head node of the list. The problem with that
design is that it makes lappend() and length() linear time. This patch
fixes that problem (and others) by maintaining a count of the list
length and a pointer to the tail node along with each head node pointer.
A "list" is now a pointer to a structure containing some meta-data
about the list; the head and tail pointers in that structure refer
to ListCell structures that maintain the actual linked list of nodes.
The function names of the list API have also been changed to, I hope,
be more logically consistent. By default, the old function names are
still available; they will be disabled-by-default once the rest of
the tree has been updated to use the new API names.
database, not just ones that we cons up POSIX names for. This looks
grim but it seems to take less than a second even on a relatively slow
machine, and since it only happens once during postmaster startup, that
seems acceptable.
of correctly identifying the system's daylight-savings transition rules.
This still begs the question of how to look through the zic database to
find a matching zone definition, but at least now we'll have some chance
of recognizing the match when we find it.
ago. This should give significantly better results when the density of
live tuples is not uniform throughout a table. Manfred Koizar, with
minor kibitzing from Tom Lane.
(SIGUSR1, which we have not been using recently) instead of piggybacking
on SIGUSR2-driven NOTIFY processing. This has several good results:
the processing needed to drain the sinval queue is a lot less than the
processing needed to answer a NOTIFY; there's less contention since we
don't have a bunch of backends all trying to acquire exclusive lock on
pg_listener; backends that are sitting inside a transaction block can
still drain the queue, whereas NOTIFY processing can't run if there's
an open transaction block. (This last is a fairly serious issue that
I don't think we ever recognized before --- with clients like JDBC that
tend to sit with open transaction blocks, the sinval queue draining
mechanism never really worked as intended, probably resulting in a lot
of useless cache-reset overhead.) This is the last of several proposed
changes in response to Philip Warner's recent report of sinval-induced
performance problems.
to ExclusiveLock. This still serializes the operations of this module,
but doesn't conflict with concurrent ANALYZE operations. Per trouble
report from Philip Warner a few weeks ago.
