explicitly fsync'ing every (non-temp) file we have written since the
last checkpoint. In the vast majority of cases, the burden of the
fsyncs should fall on the bgwriter process not on backends. (To this
end, we assume that an fsync issued by the bgwriter will force out
blocks written to the same file by other processes using other file
descriptors. Anyone have a problem with that?) This makes the world
safe for WIN32, which ain't even got sync(2), and really makes the world
safe for Unixen as well, because sync(2) never had the semantics we need:
it offers no way to wait for the requested I/O to finish.
Along the way, fix a bug I recently introduced in xlog recovery:
file truncation replay failed to clear bufmgr buffers for the dropped
blocks, which could result in 'PANIC: heap_delete_redo: no block'
later on in xlog replay.
than being random pieces of other files. Give bgwriter responsibility
for all checkpoint activity (other than a post-recovery checkpoint);
so this child process absorbs the functionality of the former transient
checkpoint and shutdown subprocesses. While at it, create an actual
include file for postmaster.c, which for some reason never had its own
file before.
this is an aclmask function and does not have the same return convention
as aclcheck functions. Also adjust the behavior so that users without
CREATE TEMP permission still have USAGE permission on their session's
temp schema. This allows privileged code to create a temp table and
make it accessible to code that's not got the same privilege. (Since
the default permissions on a table are no-access, an explicit grant on
the table will still be needed; but I see no reason that the temp schema
itself should prohibit such access.)
about a third, make it work on non-Windows platforms again. (But perhaps
I broke the WIN32 code, since I have no way to test that.) Fold all the
paths that fork postmaster child processes to go through the single
routine SubPostmasterMain, which takes care of resurrecting the state that
would normally be inherited from the postmaster (including GUC variables).
Clean up some places where there's no particularly good reason for the
EXEC and non-EXEC cases to work differently. Take care of one or two
FIXMEs that remained in the code.
of ThisStartUpID and RedoRecPtr into new backends. It's a lot easier just
to make them all grab the values out of shared memory during startup.
This helps to decouple the postmaster from checkpoint execution, which I
need since I'm intending to let the bgwriter do it instead, and it also
fixes a bug in the Win32 port: ThisStartUpID wasn't getting propagated at
all AFAICS. (Doesn't give me a lot of faith in the amount of testing that
port has gotten.)
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
