with a plpgsql-defined cursor. The underlying mechanism for this is that the
main SQL engine will now take "WHERE CURRENT OF $n" where $n is a refcursor
parameter. Not sure if we should document that fact or consider it an
implementation detail. Per discussion with Pavel Stehule.
< o Allow UPDATE/DELETE WHERE CURRENT OF cursor
<
< This requires using the row ctid to map cursor rows back to the
< original heap row. This become more complicated if WITH HOLD cursors
< are to be supported because WITH HOLD cursors have a copy of the row
< and no FOR UPDATE lock.
< http://archives.postgresql.org/pgsql-hackers/2007-01/msg01014.php
<
> o -Allow UPDATE/DELETE WHERE CURRENT OF cursor
Along the way, allow FOR UPDATE in non-WITH-HOLD cursors; there may once
have been a reason to disallow that, but it seems to work now, and it's
really rather necessary if you want to select a row via a cursor and then
update it in a concurrent-safe fashion.
Original patch by Arul Shaji, rather heavily editorialized by Tom Lane.
value for the vacuum code. Instead, make zero signify getting the value from a
higher level configuration facility, just like -1 in the original coding. We
still document that -1 is the value that disables the feature, to avoid
confusing the user unnecessarily.
Reported by Galy Lee in <200705310914.l4V9E6JA094603@wwwmaster.postgresql.org>;
per subsequent discussion.
for each temp file, rather than once per sort or hashjoin; this allows
spreading the data of a large sort or join across multiple tablespaces.
(I remain dubious that this will make any difference in practice, but certain
people insisted.) Arrange to cache the results of parsing the GUC variable
instead of recomputing from scratch on every demand, and push usage of the
cache down to the bottommost fd.c level.
were accepted by prior Postgres releases. This takes care of the loose end
left by the preceding patch to downgrade implicit casts-to-text. To avoid
breaking desirable behavior for array concatenation, introduce a new
polymorphic pseudo-type "anynonarray" --- the added concatenation operators
are actually text || anynonarray and anynonarray || text.
from the other string-category types; this eliminates a lot of surprising
interpretations that the parser could formerly make when there was no directly
applicable operator.
Create a general mechanism that supports casts to and from the standard string
types (text,varchar,bpchar) for *every* datatype, by invoking the datatype's
I/O functions. These new casts are assignment-only in the to-string direction,
explicit-only in the other, and therefore should create no surprising behavior.
Remove a bunch of thereby-obsoleted datatype-specific casting functions.
The "general mechanism" is a new expression node type CoerceViaIO that can
actually convert between *any* two datatypes if their external text
representations are compatible. This is more general than needed for the
immediate feature, but might be useful in plpgsql or other places in future.
This commit does nothing about the issue that applying the concatenation
operator || to non-text types will now fail, often with strange error messages
due to misinterpreting the operator as array concatenation. Since it often
(not always) worked before, we should either make it succeed or at least give
a more user-friendly error; but details are still under debate.
Peter Eisentraut and Tom Lane
(Possibly release notes material, lest users be confused.)
The --quiet option is now obsolete and without effect in createdb,
createuser, dropdb, dropuser; kept for compatibility but marked for
removal in 8.4.
Progress messages when acting on all databases now go to stdout instead
of stderr, since they are not in fact errors.
Ordered options in reindexdb reference page alphabetically, like in
other programs' pages.
o -Add a GUC variable to control the tablespace for temporary objects
and sort files
<
< It could start with a random tablespace from a supplied list and
< cycle through the list.
<
tablespace(s) in which to store temp tables and temporary files. This is a
list to allow spreading the load across multiple tablespaces (a random list
element is chosen each time a temp object is to be created). Temp files are
not stored in per-database pgsql_tmp/ directories anymore, but per-tablespace
directories.
Jaime Casanova and Albert Cervera, with review by Bernd Helmle and Tom Lane.
< * Allow free-behind capability for large sequential scans, perhaps using
< posix_fadvise()
> * Allow free-behind capability for large sequential scans to avoid
> kernel cache spoiling
scan-resistant:
<
< * Allow free-behind capability for large sequential scans, perhaps using
< posix_fadvise()
<
< Posix_fadvise() can control both sequential/random file caching and
< free-behind behavior, but it is unclear how the setting affects other
< backends that also have the file open, and the feature is not supported
< on all operating systems.
type. Also, add explicit casts between boolean and text/varchar. Both
of these changes are for conformance with SQL:2003.
Update the regression tests, bump the catversion.
< * Consider allowing 64-bit integers to be passed by value on 64-bit
< platforms
> * Consider allowing 64-bit integers and floats to be passed by value on
> 64-bit platforms
>
> Also change 32-bit floats (float4) to be passed by value at the same
> time.
>
* Improve speed with indexes
For large table adjustments during VACUUM FULL, it is faster to cluster
or reindex rather than update the index. Also, index updates can bloat
the index.
"microsecond" and "millisecond" units were not considered valid input
by themselves, which caused inputs like "1 millisecond" to be rejected
erroneously.
Update the docs, add regression tests, and backport to 8.2 and 8.1
- Function renamed to "xpath".
- Function is now strict, per discussion.
- Return empty array in case when XPath expression detects nothing
(previously, NULL was returned in such case), per discussion.
- (bugfix) Work with fragments with prologue: select xpath('/a',
'<?xml version="1.0"?><a /><b />'); // now XML datum is always wrapped
with dummy <x>...</x>, XML prologue simply goes away (if any).
- Some cleanup.
Nikolay Samokhvalov
Some code cleanup and documentation work by myself.
>
> * Implement the SQL standard mechanism whereby REVOKE ROLE revokes only
> the privilege granted by the invoking role, and not those granted
> by other roles
parentheses in syntax descriptions. Consistently use the present tense
when describing the basic purpose of each "DROP" command. Add a few
more hyperlinks.
"autovacuum = off", the system may still periodically start autovacuum
processes to prevent XID wraparound. Patch from David Fetter, with
editorializing.
named foo, would work but the other ordering would not. If a user-specified
type or table name collides with an existing auto-generated array name, just
rename the array type out of the way by prepending more underscores. This
should not create any backward-compatibility issues, since the cases in which
this will happen would have failed outright in prior releases.
Also fix an oversight in the arrays-of-composites patch: ALTER TABLE RENAME
renamed the table's rowtype but not its array type.
needs to check the new constraint against columns of derived domains too.
Also, make it error out if the domain to be modified is used within any
composite-type columns. Eventually we should support that case, but it seems
a bit painful, and not suitable for a back-patch. For the moment just let the
user know we can't do it.
Backpatch to 8.2, which is the only released version that allows nested
domains. Possibly the other part should be back-patched further.
and views (but not system catalogs, nor sequences or toast tables). Get rid
of the hardwired convention that a type's array type is named exactly "_type",
instead using a new column pg_type.typarray to provide the linkage. (It still
will be named "_type", though, except in odd corner cases such as
maximum-length type names.)
Along the way, make tracking of owner and schema dependencies for types more
uniform: a type directly created by the user has these dependencies, while a
table rowtype or auto-generated array type does not have them, but depends on
its parent object instead.
David Fetter, Andrew Dunstan, Tom Lane
sign convention from everyplace else in Postgres. I don't suppose that
this will stop people from being confused, but at least we can say that
it's documented.
< Last updated: Sat May 5 10:47:39 EDT 2007
> Last updated: Sat May 5 11:39:57 EDT 2007
< * Flush cached query plans when the dependent objects change,
< when the cardinality of parameters changes dramatically, or
> * -Flush cached query plans when the dependent objects change or
<
< A more complex solution would be to save multiple plans for different
< cardinality and use the appropriate plan based on the EXECUTE values.
<
< * Track dependencies in function bodies and recompile/invalidate
<
< This is particularly important for references to temporary tables
< in PL/PgSQL because PL/PgSQL caches query plans. The only workaround
< in PL/PgSQL is to use EXECUTE. One complexity is that a function
< might itself drop and recreate dependent tables, causing it to
< invalidate its own query plan.
<
< * Invalidate prepared queries, like INSERT, when the table definition
> * -Track dependencies in function bodies and recompile/invalidate
> * -Invalidate prepared queries, like INSERT, when the table definition
< * Invalidate prepared queries, like INSERT, when the table definition
< is altered
>
> * Invalidate prepared queries, like INSERT, when the table definition
> is altered
> * -Allow ORDER BY ... LIMIT # to select high/low value without sort or
<
< Right now, if no index exists, ORDER BY ... LIMIT # requires we sort
< all values to return the high/low value. Instead The idea is to do a
< sequential scan to find the high/low value, thus avoiding the sort.
< MIN/MAX already does this, but not for LIMIT > 1.
<
< o Add support for MOVE and SCROLL cursors
<
< PL/pgSQL cursors should support the same syntax as
< backend cursors.
<
> o -Add support for MOVE cursors
> o Add support for SCROLL cursors
RESET SESSION, RESET PLANS, and RESET TEMP are now DISCARD ALL,
DISCARD PLANS, and DISCARD TEMP, respectively. This is to avoid
confusion with the pre-existing RESET variants: the DISCARD
commands are not actually similar to RESET. Patch from Marko
Kreen, with some minor editorialization.
This is needed to allow a security-definer function to set a truly secure
value of search_path. Without it, a malicious user can use temporary objects
to execute code with the privileges of the security-definer function. Even
pushing the temp schema to the back of the search path is not quite good
enough, because a function or operator at the back of the path might still
capture control from one nearer the front due to having a more exact datatype
match. Hence, disable searching the temp schema altogether for functions and
operators.
Security: CVE-2007-2138
