we regenerate the SQL query text not merely the plan derived from it. This
is needed to handle contingencies such as renaming of a table or column
used in an FK. Pre-8.3, such cases worked despite the lack of replanning
(because the cached plan needn't actually change), so this is a regression.
Per bug #4417 from Benjamin Bihler.
when user-defined functions used in a plan are modified. Also invalidate
plans when schemas, operators, or operator classes are modified; but for these
cases we just invalidate everything rather than tracking exact dependencies,
since these types of objects seldom change in a production database.
Tom Lane; loosely based on a patch by Martin Pihlak.
into nodes/nodeFuncs, so as to reduce wanton cross-subsystem #includes inside
the backend. There's probably more that should be done along this line,
but this is a start anyway.
REINDEX DATABASE including same) is done before a session has done any other
update on pg_class, the pg_class relcache entry was left with an incorrect
setting of rd_indexattr, because the indexed-attributes set would be first
demanded at a time when we'd forced a partial list of indexes into the
pg_class entry, and it would remain cached after that. This could result
in incorrect decisions about HOT-update safety later in the same session.
In practice, since only pg_class_relname_nsp_index would be missed out,
only ALTER TABLE RENAME and ALTER TABLE SET SCHEMA could trigger a problem.
Per report and test case from Ondrej Jirman.
as per my recent proposal:
1. Fold SortClause and GroupClause into a single node type SortGroupClause.
We were already relying on them to be struct-equivalent, so using two node
tags wasn't accomplishing much except to get in the way of comparing items
with equal().
2. Add an "eqop" field to SortGroupClause to carry the associated equality
operator. This is cheap for the parser to get at the same time it's looking
up the sort operator, and storing it eliminates the need for repeated
not-so-cheap lookups during planning. In future this will also let us
represent GROUP/DISTINCT operations on datatypes that have hash opclasses
but no btree opclasses (ie, they have equality but no natural sort order).
The previous representation simply didn't work for that, since its only
indicator of comparison semantics was a sort operator.
3. Add a hasDistinctOn boolean to struct Query to explicitly record whether
the distinctClause came from DISTINCT or DISTINCT ON. This allows removing
some complicated and not 100% bulletproof code that attempted to figure
that out from the distinctClause alone.
This patch doesn't in itself create any new capability, but it's necessary
infrastructure for future attempts to use hash-based grouping for DISTINCT
and UNION/INTERSECT/EXCEPT.
with system catalog lookups, as was foreseen to be necessary almost since
their creation. Instead put the information into two new pg_type columns,
typcategory and typispreferred. Add support for setting these when
creating a user-defined base type.
The category column is just a "char" (i.e. a poor man's enum), allowing
a crude form of user extensibility of the category list: just use an
otherwise-unused character. This seems sufficient for foreseen uses,
but we could upgrade to having an actual category catalog someday, if
there proves to be a huge demand for custom type categories.
In this patch I have attempted to hew exactly to the behavior of the
previous hardwired logic, except for introducing new type categories for
arrays, composites, and enums. In particular the default preferred state
for user-defined types remains TRUE. That seems worth revisiting, but it
should be done as a separate patch from introducing the infrastructure.
Likewise, any adjustment of the standard set of categories should be done
separately.
a portal are never NULL, but reliably provide the source text of the query.
It turns out that there was only one place that was really taking a short-cut,
which was the 'EXECUTE' utility statement. That doesn't seem like a
sufficiently critical performance hotspot to justify not offering a guarantee
of validity of the portal source text. Fix it to copy the source text over
from the cached plan. Add Asserts in the places that set up cached plans and
portals to reject null source strings, and simplify a bunch of places that
formerly needed to guard against nulls.
There may be a few places that cons up statements for execution without
having any source text at all; I found one such in ConvertTriggerToFK().
It seems sufficient to inject a phony source string in such a case,
for instance
ProcessUtility((Node *) atstmt,
"(generated ALTER TABLE ADD FOREIGN KEY command)",
NULL, false, None_Receiver, NULL);
We should take a second look at the usage of debug_query_string,
particularly the recently added current_query() SQL function.
ITAGAKI Takahiro and Tom Lane
unnecessary cache resets. The major changes are:
* When the queue overflows, we only issue a cache reset to the specific
backend or backends that still haven't read the oldest message, rather
than resetting everyone as in the original coding.
* When we observe backend(s) falling well behind, we signal SIGUSR1
to only one backend, the one that is furthest behind and doesn't already
have a signal outstanding for it. When it finishes catching up, it will
in turn signal SIGUSR1 to the next-furthest-back guy, if there is one that
is far enough behind to justify a signal. The PMSIGNAL_WAKEN_CHILDREN
mechanism is removed.
* We don't attempt to clean out dead messages after every message-receipt
operation; rather, we do it on the insertion side, and only when the queue
fullness passes certain thresholds.
* Split SInvalLock into SInvalReadLock and SInvalWriteLock so that readers
don't block writers nor vice versa (except during the infrequent queue
cleanout operations).
* Transfer multiple sinval messages for each acquisition of a read or
write lock.
corresponding struct definitions. This allows other headers to avoid including
certain highly-loaded headers such as rel.h and relscan.h, instead using just
relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less
unnecessary dependencies.
There are two ways to track a snapshot: there's the "registered" list, which
is used for arbitrary long-lived snapshots; and there's the "active stack",
which is used for the snapshot that is considered "active" at any time.
This also allows users of snapshots to stop worrying about snapshot memory
allocation and freeing, and about using PG_TRY blocks around ActiveSnapshot
assignment. This is all done automatically now.
As a consequence, this allows us to reset MyProc->xmin when there are no
more snapshots registered in the current backend, reducing the impact that
long-running transactions have on VACUUM.
unnecessary #include lines in it. Also, move some tuple routine prototypes and
macros to htup.h, which allows removal of heapam.h inclusion from some .c
files.
For this to work, a new header file access/sysattr.h needed to be created,
initially containing attribute numbers of system columns, for pg_dump usage.
While at it, make contrib ltree, intarray and hstore header files more
consistent with our header style.
it is trying to build a relcache entry for. This is an oversight in my 8.2
patch that tried to ensure we always took a lock on a relation before trying
to build its relcache entry. The implication is that if someone committed a
reindex of a critical system index at about the same time that some other
backend were starting up without a valid pg_internal.init file, the second one
might PANIC due to not seeing any valid version of the index's pg_class row.
Improbable case, but definitely not impossible.
no particular need to do get_op_opfamily_properties() while building an
indexscan plan. Postpone that lookup until executor start. This simplifies
createplan.c a lot more than it complicates nodeIndexscan.c, and makes things
more uniform since we already had to do it that way for RowCompare
expressions. Should be a bit faster too, at least for plans that aren't
re-used many times, since we avoid palloc'ing and perhaps copying the
intermediate list data structure.
systable_endscan_ordered that have API similar to systable_beginscan etc
(in particular, the passed-in scankeys have heap not index attnums),
but guarantee ordered output, unlike the existing functions. For the moment
these are just very thin wrappers around index_beginscan/index_getnext/etc.
Someday they might need to get smarter; but for now this is just a code
refactoring exercise to reduce the number of direct callers of index_getnext,
in preparation for changing that function's API.
In passing, remove index_getnext_indexitem, which has been dead code for
quite some time, and will have even less use than that in the presence
of run-time-lossy indexes.
eval_const_expressions needs to be passed the PlannerInfo ("root") structure,
because in some cases we want it to substitute values for Param nodes.
(So "constant" is not so constant as all that ...) This mistake partially
disabled optimization of unnamed extended-Query statements in 8.3: in
particular the LIKE-to-indexscan optimization would never be applied if the
LIKE pattern was passed as a parameter, and constraint exclusion depending
on a parameter value didn't work either.
snapmgmt.c file for the former. The header files have also been reorganized
in three parts: the most basic snapshot definitions are now in a new file
snapshot.h, and the also new snapmgmt.h keeps the definitions for snapmgmt.c.
tqual.h has been reduced to the bare minimum.
This patch is just a first step towards managing live snapshots within a
transaction; there is no functionality change.
Per my proposal to pgsql-patches on 20080318191940.GB27458@alvh.no-ip.org and
subsequent discussion.
strings. This patch introduces four support functions cstring_to_text,
cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and
two macros CStringGetTextDatum and TextDatumGetCString. A number of
existing macros that provided variants on these themes were removed.
Most of the places that need to make such conversions now require just one
function or macro call, in place of the multiple notational layers that used
to be needed. There are no longer any direct calls of textout or textin,
and we got most of the places that were using handmade conversions via
memcpy (there may be a few still lurking, though).
This commit doesn't make any serious effort to eliminate transient memory
leaks caused by detoasting toasted text objects before they reach
text_to_cstring. We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few
places where it was easy, but much more could be done.
Brendan Jurd and Tom Lane
messages if the calling transaction aborts later on. Collapsing out line
pointer redirects is a done deal as soon as we complete the page update,
so syscache *must* be notified even if the VACUUM FULL as a whole doesn't
complete. To fix, add some functionality to inval.c to allow the pending
inval messages to be sent immediately while heap_page_prune is still
running. The implementation is a bit chintzy: it will only work in the
context of VACUUM FULL. But that's all we need now, and it can always be
extended later if needed. Per my trouble report of a week ago.
caches that we don't actually need to touch. This saves some trivial
number of cycles and avoids certain cases of deadlock when doing concurrent
VACUUM FULL on system catalogs. Per report from Gavin Roy.
Backpatch to 8.2. In earlier versions, CatalogCacheInitializeCache didn't
lock the relation so there's no deadlock risk (though that certainly had
plenty of risks of its own).
but no database changes have been made since the last CommandCounterIncrement.
This should result in a significant improvement in the number of "commands"
that can typically be performed within a transaction before hitting the 2^32
CommandId size limit. In particular this buys back (and more) the possible
adverse consequences of my previous patch to fix plan caching behavior.
The implementation requires tracking whether the current CommandCounter
value has been "used" to mark any tuples. CommandCounter values stored into
snapshots are presumed not to be used for this purpose. This requires some
small executor changes, since the executor used to conflate the curcid of
the snapshot it was using with the command ID to mark output tuples with.
Separating these concepts allows some small simplifications in executor APIs.
Something for the TODO list: look into having CommandCounterIncrement not do
AcceptInvalidationMessages. It seems fairly bogus to be doing it there,
but exactly where to do it instead isn't clear, and I'm disinclined to mess
with asynchronous behavior during late beta.
reloading of operator class information on each use of LookupOpclassInfo.
Had this been in place a year ago, it would have helped me find a bug
in the then-new 'operator family' code. Now that we have a build farm
member testing CLOBBER_CACHE_ALWAYS on a regular basis, it seems worth
expending a little bit of effort here.
it affects. The original coding neglected tablespace entirely (causing
the indexes to move to the database's default tablespace) and for an index
belonging to a UNIQUE or PRIMARY KEY constraint, it would actually try to
assign the parent table's reloptions to the index :-(. Per bug #3672 and
subsequent investigation.
8.0 and 8.1 did not have reloptions, but the tablespace bug is present.
a relation as a reason to invalidate a plan when the relation changes. This
handles scenarios such as dropping/recreating a sequence that is referenced by
nextval('seq') in a cached plan. Rather than teach plancache.c all about
digging through plan trees to find regclass Consts, we charge the planner's
setrefs.c with making a list of the relation OIDs on which each plan depends.
That way the list can be built cheaply during a plan tree traversal that has
to happen anyway. Per bug #3662 and subsequent discussion.
columns, and the new version can be stored on the same heap page, we no longer
generate extra index entries for the new version. Instead, index searches
follow the HOT-chain links to ensure they find the correct tuple version.
In addition, this patch introduces the ability to "prune" dead tuples on a
per-page basis, without having to do a complete VACUUM pass to recover space.
VACUUM is still needed to clean up dead index entries, however.
Pavan Deolasee, with help from a bunch of other people.
and in passing, fix some bogosities dating from the custom_variable_classes
patch. Fix guc-file.l to correctly check changes in custom_variable_classes
that are attempted concurrently with additions/removals of custom variables,
and don't allow the new setting to be applied in advance of checking it.
Clean up messy and undocumented situation for string variables with NULL
boot_val. Fix DefineCustomVariable functions to initialize boot_val
correctly. Prevent find_option from inserting bogus placeholders for custom
variables that are simply inquired about rather than being set.
init options of the template as top-level options in the syntax. This also
makes ALTER a bit easier to use, since options can be replaced individually.
I also made these statements verify that the tmplinit method will accept
the new settings before they get stored; in the original coding you didn't
find out about mistakes until the dictionary got invoked.
Under the hood, init methods now get options as a List of DefElem instead
of a raw text string --- that lets tsearch use existing options-pushing code
instead of duplicating functionality.
Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.
Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.
named pg_toast_temp_nnn, alongside the pg_temp_nnn schemas used for the temp
tables themselves. This allows low-level code such as the relcache to
recognize that these tables are indeed temporary, which enables various
optimizations such as not WAL-logging changes and using local rather than
shared buffers for access. Aside from obvious performance benefits, this
provides a solution to bug #3483, in which other backends unexpectedly held
open file references to temporary tables. The scheme preserves the property
that TOAST tables are not in any schema that's normally in the search path,
so they don't conflict with user table names.
initdb forced because of changes in system view definitions.
a session regardless of the existence of cached plans. The plancache
only needs to be invalidated so that rules affected by the new setting
will be reflected in the new query plans.
Jan
and aborted transactions have different effects; also teach it not to assume
that prepared transactions are always committed.
Along the way, simplify the pgstats API by tying counting directly to
Relations; I cannot detect any redeeming social value in having stats
pointers in HeapScanDesc and IndexScanDesc structures. And fix a few
corner cases in which counts might be missed because the relation's
pgstat_info pointer hadn't been set.
ActiveSnapshot. Having it affect ActiveSnapshot only in the unusual
case of needing to replan seems a bad idea, and there's also the problem
that the created snap might be in a relatively short-lived context, as
noted by Jan Wieck. Also, there's no need to force a new snap at all
unless we are called with no snap currently set, which is an unusual
case in itself.
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
true at the very end of its processing, the update is broadcast via a
shared-cache-inval message for the index; without this, existing backends that
already have relcache entries for the index might never see it become valid.
Also, force a relcache inval on the index's parent table at the same time,
so that any cached plans for that table are re-planned; this ensures that
the newly valid index will be used if appropriate. Aside from making
C.I.C. behave more reasonably, this is necessary infrastructure for some
aspects of the HOT patch. Pavan Deolasee, with a little further stuff from
me.
values: don't throw away perfectly good hash bits, and increase the shift
distances so as to provide more separation in the common case where some of
the key values are small integers (and so their hashes are too, because
hashfunc.c doesn't try all that hard). This reduces the runtime of
SearchCatCache by a factor of 4 in an example provided by Greg Stark,
in which the planner spends a whole lot of time searching the two-key
STATRELATT cache. It seems unlikely to hurt in other cases, but maybe
we could do even better?
a replan. I had originally thought this was not necessary, but the new
SPI facilities create a path whereby queries planned with non-default
options can get into the cache, so it is necessary.
access to the planner's cursor-related planning options, and provide new
FETCH/MOVE routines that allow access to the full power of those commands.
Small refactoring of planner(), pg_plan_query(), and pg_plan_queries()
APIs to make it convenient to pass the planning options down from SPI.
This is the core-code portion of Pavel Stehule's patch for scrollable
cursor support in plpgsql; I'll review and apply the plpgsql changes
separately.
reviewed by Neil Conway. This patch adds the following DDL command
variants: RESET SESSION, RESET TEMP, RESET PLANS, CLOSE ALL, and
DEALLOCATE ALL. RESET SESSION is intended for use by connection
pool software and the like, in order to reset a client session
to something close to its initial state.
Note that while most of these command variants can be executed
inside a transaction block (but are not transaction-aware!),
RESET SESSION cannot. While this is inconsistent, it is intended
to catch programmer mistakes: RESET SESSION in an open transaction
block is probably unintended.
reset event, namely invalidate everything. This oversight probably
explains the rare failures that some buildfarm machines have been
showing for the plancache regression test.
search_path that was active when the plan was first made. To do this,
improve namespace.c to support a stack of "override" search path settings
(we must have a stack since nested replan events are entirely possible).
This facility replaces the "special namespace" hack formerly used by
CREATE SCHEMA, and should be able to support per-function search path
settings as well.
rules to be defined with different, per session controllable, behaviors
for replication purposes.
This will allow replication systems like Slony-I and, as has been stated
on pgsql-hackers, other products to control the firing mechanism of
triggers and rewrite rules without modifying the system catalog directly.
The firing mechanisms are controlled by a new superuser-only GUC
variable, session_replication_role, together with a change to
pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both
columns are a single char data type now (tgenabled was a bool before).
The possible values in these attributes are:
'O' - Trigger/Rule fires when session_replication_role is "origin"
(default) or "local". This is the default behavior.
'D' - Trigger/Rule is disabled and fires never
'A' - Trigger/Rule fires always regardless of the setting of
session_replication_role
'R' - Trigger/Rule fires when session_replication_role is "replica"
The GUC variable can only be changed as long as the system does not have
any cached query plans. This will prevent changing the session role and
accidentally executing stored procedures or functions that have plans
cached that expand to the wrong query set due to differences in the rule
firing semantics.
The SQL syntax for changing a triggers/rules firing semantics is
ALTER TABLE <tabname> <when> TRIGGER|RULE <name>;
<when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE
psql's \d command as well as pg_dump are extended in a backward
compatible fashion.
Jan
available information about the typmod of an expression; namely, Const,
ArrayRef, ArrayExpr, and EXPR and ARRAY SubLinks. In the ArrayExpr and
SubLink cases it wasn't really the data structure's fault, but exprTypmod()
being lazy. This seems like a good idea in view of the expected increase in
typmod usage from Teodor's work to allow user-defined types to have typmods.
In particular this responds to the concerns we had about eliminating the
special-purpose hack that exprTypmod() used to have for BPCHAR Consts.
We can now tell whether or not such a Const has been cast to a specific
length, and report or display properly if so.
initdb forced due to changes in stored rules.
uses SPI plans, this finally fixes the ancient gotcha that you can't
drop and recreate a temp table used by a plpgsql function.
Along the way, clean up SPI's API a little bit by declaring SPI plan
pointers as "SPIPlanPtr" instead of "void *". This is cosmetic but
helps to forestall simple programming mistakes. (I have changed some
but not all of the callers to match; there are still some "void *"'s
in contrib and the PL's. This is intentional so that we can see if
anyone's compiler complains about it.)
module and teach PREPARE and protocol-level prepared statements to use it.
In service of this, rearrange utility-statement processing so that parse
analysis does not assume table schemas can't change before execution for
utility statements (necessary because we don't attempt to re-acquire locks
for utility statements when reusing a stored plan). This requires some
refactoring of the ProcessUtility API, but it ends up cleaner anyway,
for instance we can get rid of the QueryContext global.
Still to do: fix up SPI and related code to use the plan cache; I'm tempted to
try to make SQL functions use it too. Also, there are at least some aspects
of system state that we want to ensure remain the same during a replan as in
the original processing; search_path certainly ought to behave that way for
instance, and perhaps there are others.
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with
VARSIZE and VARDATA, and as a consequence almost no code was using the
longer names. Rename the length fields of struct varlena and various
derived structures to catch anyplace that was accessing them directly;
and clean up various places so caught. In itself this patch doesn't
change any behavior at all, but it is necessary infrastructure if we hope
to play any games with the representation of varlena headers.
Greg Stark and Tom Lane
equality checks it applies, instead of a random dependence on whatever
operators might be named "=". The equality operators will now be selected
from the opfamily of the unique index that the FK constraint depends on to
enforce uniqueness of the referenced columns; therefore they are certain to be
consistent with that index's notion of equality. Among other things this
should fix the problem noted awhile back that pg_dump may fail for foreign-key
constraints on user-defined types when the required operators aren't in the
search path. This also means that the former warning condition about "foreign
key constraint will require costly sequential scans" is gone: if the
comparison condition isn't indexable then we'll reject the constraint
entirely. All per past discussions.
Along the way, make the RI triggers look into pg_constraint for their
information, instead of using pg_trigger.tgargs; and get rid of the always
error-prone fixed-size string buffers in ri_triggers.c in favor of building up
the RI queries in StringInfo buffers.
initdb forced due to columns added to pg_constraint and pg_trigger.
Hashing for aggregation purposes still needs work, so it's not time to
mark any cross-type operators as hashable for general use, but these cases
work if the operators are so marked by hand in the system catalogs.
columns procost and prorows, to allow simple user adjustment of the estimated
cost of a function call, as well as control of the estimated number of rows
returned by a set-returning function. We might eventually wish to extend this
to allow function-specific estimation routines, but there seems to be
consensus that we should try a simple constant estimate first. In particular
this provides a relatively simple way to control the order in which different
WHERE clauses are applied in a plan node, which is a Good Thing in view of the
fact that the recent EquivalenceClass planner rewrite made that much less
predictable than before.
representation of equivalence classes of variables. This is an extensive
rewrite, but it brings a number of benefits:
* planner no longer fails in the presence of "incomplete" operator families
that don't offer operators for every possible combination of datatypes.
* avoid generating and then discarding redundant equality clauses.
* remove bogus assumption that derived equalities always use operators
named "=".
* mergejoins can work with a variety of sort orders (e.g., descending) now,
instead of tying each mergejoinable operator to exactly one sort order.
* better recognition of redundant sort columns.
* can make use of equalities appearing underneath an outer join.
which comparison operators to use for plan nodes involving tuple comparison
(Agg, Group, Unique, SetOp). Formerly the executor looked up the default
equality operator for the datatype, which was really pretty shaky, since it's
possible that the data being fed to the node is sorted according to some
nondefault operator class that could have an incompatible idea of equality.
The planner knows what it has sorted by and therefore can provide the right
equality operator to use. Also, this change moves a couple of catalog lookups
out of the executor and into the planner, which should help startup time for
pre-planned queries by some small amount. Modify the planner to remove some
other cavalier assumptions about always being able to use the default
operators. Also add "nulls first/last" info to the Plan node for a mergejoin
--- neither the executor nor the planner can cope yet, but at least the API is
in place.
per-column options for btree indexes. The planner's support for this is still
pretty rudimentary; it does not yet know how to plan mergejoins with
nondefault ordering options. The documentation is pretty rudimentary, too.
I'll work on improving that stuff later.
Note incompatible change from prior behavior: ORDER BY ... USING will now be
rejected if the operator is not a less-than or greater-than member of some
btree opclass. This prevents less-than-sane behavior if an operator that
doesn't actually define a proper sort ordering is selected.
pg_opclass during LookupOpclassInfo(), I'd turned pg_opclass_oid_index
into a critical system index. However the problem could only manifest
during a backend's first attempt to load opclass data, and then only
if it had successfully loaded pg_internal.init and subsequently received
a relcache flush; which made it impossible to reproduce in sequential
tests and darn hard even in parallel tests. Memo to self: when
exercising cache flush scenarios, must disable LookupOpclassInfo's
internal cache too.
cases. Operator classes now exist within "operator families". While most
families are equivalent to a single class, related classes can be grouped
into one family to represent the fact that they are semantically compatible.
Cross-type operators are now naturally adjunct parts of a family, without
having to wedge them into a particular opclass as we had done originally.
This commit restructures the catalogs and cleans up enough of the fallout so
that everything still works at least as well as before, but most of the work
needed to actually improve the planner's behavior will come later. Also,
there are not yet CREATE/DROP/ALTER OPERATOR FAMILY commands; the only way
to create a new family right now is to allow CREATE OPERATOR CLASS to make
one by default. I owe some more documentation work, too. But that can all
be done in smaller pieces once this infrastructure is in place.
stale relcache init files (pg_internal.init), and there is no mechanism for
updating them during WAL replay. Easiest solution is just to delete the init
files at conclusion of startup, and let the first backend started in each
database take care of rebuilding the init file. Simon Riggs and Tom Lane.
Back-patched to 8.1. Arguably this should be fixed in 8.0 too, but it would
require significantly more code since 8.0 has no handy startup-time scan of
pg_database to piggyback on. Manual solution of the problem is possible
in 8.0 (just delete the pg_internal.init files before starting WAL replay),
so that may be a sufficient answer.
been initialized yet. This can happen because there are code paths that call
SysCacheGetAttr() on a tuple originally fetched from a different syscache
(hopefully on the same catalog) than the one specified in the call. It
doesn't seem useful or robust to try to prevent that from happening, so just
improve the function to cope instead. Per bug#2678 from Jeff Trout. The
specific example shown by Jeff is new in 8.1, but to be on the safe side
I'm backpatching 8.0 as well. We could patch 7.x similarly but I think
that's probably overkill, given the lack of evidence of old bugs of this ilk.
the SQL spec, viz IS NULL is true if all the row's fields are null, IS NOT
NULL is true if all the row's fields are not null. The former coding got
this right for a limited number of cases with IS NULL (ie, those where it
could disassemble a ROW constructor at parse time), but was entirely wrong
for IS NOT NULL. Per report from Teodor.
I desisted from changing the behavior for arrays, since on closer inspection
it's not clear that there's any support for that in the SQL spec. This
probably needs more consideration.
can create or modify rules for the table. Do setRuleCheckAsUser() while
loading rules into the relcache, rather than when defining a rule. This
ensures that permission checks for tables referenced in a rule are done with
respect to the current owner of the rule's table, whereas formerly ALTER TABLE
OWNER would fail to update the permission checking for associated rules.
Removal of separate RULE privilege is needed to prevent various scenarios
in which a grantee of RULE privilege could effectively have any privilege
of the table owner. For backwards compatibility, GRANT/REVOKE RULE is still
accepted, but it doesn't do anything. Per discussion here:
http://archives.postgresql.org/pgsql-hackers/2006-04/msg01138.php
internal TypInfo table in bootstrap mode. This allows array_in and
array_out to be used during early bootstrap, which eliminates the
former obstacle to giving OUT parameters to built-in functions.
(table or index) before trying to open its relcache entry. This fixes
race conditions in which someone else commits a change to the relation's
catalog entries while we are in process of doing relcache load. Problems
of that ilk have been reported sporadically for years, but it was not
really practical to fix until recently --- for instance, the recent
addition of WAL-log support for in-place updates helped.
Along the way, remove pg_am.amconcurrent: all AMs are now expected to support
concurrent update.
discussion (including making def_arg allow reserved words), add missed
opt_definition for UNIQUE case. Put the reloptions support code in a less
random place (I chose to make a new file access/common/reloptions.c).
Eliminate header inclusion creep. Make the index options functions safely
user-callable (seems like client apps might like to be able to test validity
of options before trying to make an index). Reduce overhead for normal case
with no options by allowing rd_options to be NULL. Fix some unmaintainably
klugy code, including getting rid of Natts_pg_class_fixed at long last.
Some stylistic cleanup too, and pay attention to keeping comments in sync
with code.
Documentation still needs work, though I did fix the omissions in
catalogs.sgml and indexam.sgml.
by creating a reference-count mechanism, similar to what we did a long time
ago for catcache entries. The back branches have an ugly solution involving
lots of extra copies, but this way is more efficient. Reference counting is
only applied to tupdescs that are actually in caches --- there seems no need
to use it for tupdescs that are generated in the executor, since they'll go
away during plan shutdown by virtue of being in the per-query memory context.
Neil Conway and Tom Lane
remove the infrastructure needed to enforce the limit, ie, the global
LRU list of cache entries. On small-to-middling databases this wins
because maintaining the LRU list is a waste of time. On large databases
this wins because it's better to keep more cache entries (we assume
such users can afford to use some more per-backend memory than was
contemplated in the Berkeley-era catcache design). This provides a
noticeable improvement in the speed of psql \d on a 10000-table
database, though it doesn't make it instantaneous.
While at it, use per-catcache settings for the number of hash buckets
per catcache, rather than the former one-size-fits-all value. It's a
bit silly to be using the same number of hash buckets for, eg, pg_am
and pg_attribute. The specific values I used might need some tuning,
but they seem to be in the right ballpark based on CATCACHE_STATS
results from the standard regression tests.
it's not necessary to have three separate calls anymore. This patch also
fixes things so we don't try to read pg_internal.init until after we've
obtained lock on the target database; which was fairly harmless, but it's
certainly cleaner this way.
in various places that were previously doing ad hoc pg_database searches.
This may speed up database-related privilege checks a little bit, but
the main motivation is to eliminate the performance reason for having
ReverifyMyDatabase do such a lot of stuff (viz, avoiding repeat scans
of pg_database during backend startup). The locking reason for having
that routine is about to go away, and it'd be good to have the option
to break it up.
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.
that apply the necessary domain constraint checks immediately. This fixes
cases where domain constraints went unchecked for statement parameters,
PL function local variables and results, etc. We can also eliminate existing
special cases for domains in places that had gotten it right, eg COPY.
Also, allow domains over domains (base of a domain is another domain type).
This almost worked before, but was disallowed because the original patch
hadn't gotten it quite right.
functions are not strict, they will be called (passing a NULL first parameter)
during any attempt to input a NULL value of their datatype. Currently, all
our input functions are strict and so this commit does not change any
behavior. However, this will make it possible to build domain input functions
that centralize checking of domain constraints, thereby closing numerous holes
in our domain support, as per previous discussion.
While at it, I took the opportunity to introduce convenience functions
InputFunctionCall, OutputFunctionCall, etc to use in code that calls I/O
functions. This eliminates a lot of grotty-looking casts, but the main
motivation is to make it easier to grep for these places if we ever need
to touch them again.
regardless of the current schema search path. Since CREATE OPERATOR CLASS
only allows one default opclass per datatype regardless of schemas, this
should have minimal impact, and it fixes problems with failure to find a
desired opclass while restoring dump files. Per discussion at
http://archives.postgresql.org/pgsql-hackers/2006-02/msg00284.php.
Remove now-redundant-or-unused code in typcache.c and namespace.c,
and backpatch as far as 8.0.
index's support-function cache (in index_getprocinfo). Since none of that
data can change for an index that's in active use, it seems sufficient to
treat all open indexes the same way we were treating "nailed" system indexes
--- that is, just re-read the pg_class row and leave the rest of the relcache
entry strictly alone. The pg_class re-read might not be strictly necessary
either, but since the reltablespace and relfilenode can change in normal
operation it seems safest to do it. (We don't support changing any of the
other info about an index at all, at the moment.)
Back-patch as far as 8.0. It might be possible to adapt the patch to 7.4,
but it would take more work than I care to expend for such a low-probability
problem. 7.3 is out of luck for sure.
This is utterly insignificant in normal operation, but it becomes a
problem during cache inval stress testing. The original coding in fact
had no leak --- the 8.0 List rewrite created the issue. I wonder whether
list_concat should pfree the discarded header?
and nail a couple more system indexes into cache. This doesn't make
any difference in normal system operation, but when forcing constant
cache resets it's difficult to get through the rules regression test
without these changes.
dead and have become unreferenced. Before 8.1, such members were left
for AtEOXact_CatCache() to clean up, but now AtEOXact_CatCache isn't
supposed to have anything to do. In an assert-enabled build this bug
leads to an assertion failure at transaction end, but in a non-assert
build the dead member is effectively just a small memory leak.
Per report from Jeremy Drake.
(previously we only did = and <> correctly). Also, allow row comparisons
with any operators that are in btree opclasses, not only those with these
specific names. This gets rid of a whole lot of indefensible assumptions
about the behavior of particular operators based on their names ... though
it's still true that IN and NOT IN expand to "= ANY". The patch adds a
RowCompareExpr expression node type, and makes some changes in the
representation of ANY/ALL/ROWCOMPARE SubLinks so that they can share code
with RowCompareExpr.
I have not yet done anything about making RowCompareExpr an indexable
operator, but will look at that soon.
initdb forced due to changes in stored rules.
the data defining the semantics of a lock method (ie, conflict resolution
table and ancillary data, which is all constant) and the hash tables
storing the current state. The only thing we give up by this is the
ability to use separate hashtables for different lock methods, but there
is no need for that anyway. Put some extra fields into the LockMethod
definition structs to clean up some other uglinesses, like hard-wired
tests for DEFAULT_LOCKMETHOD and USER_LOCKMETHOD. This commit doesn't
do anything about the performance issues we were discussing, but it clears
away some of the underbrush that's in the way of fixing that.
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
functionality, but I still need to make another pass looking at places
that incidentally use arrays (such as ACL manipulation) to make sure they
are null-safe. Contrib needs work too.
I have not changed the behaviors that are still under discussion about
array comparison and what to do with lower bounds.
valid type information if they are asked to fetch the values part of a
pg_statistic slot; these arguments are unneeded if fetching only the
numbers part. Use this to save a catcache lookup in btcostestimate,
which is looking like a bit of a hotspot in recent profiling. Not a
big savings, but since it's essentially free, might as well do it.
the parent table, even if the command that creates them is executed by
someone else (such as a superuser or a member of the owning role).
Per gripe from Michael Fuhr.
SearchCatCacheList and ReleaseCatCacheList. Previously, we incremented
and decremented the refcounts of list member tuples along with the list
itself, but that's unnecessary, and very expensive when the list is big.
It's cheaper to change only the list refcount. When we are considering
deleting a cache entry, we have to check not only its own refcount but
its parent list's ... but it's easy to arrange the code so that this
check is not made in any commonly-used paths, so the cost is really nil.
The bigger gain though is to refrain from DLMoveToFront'ing each individual
member tuple each time the list is referenced. To keep some semblance
of fair space management, lists are just marked as used or not since the
last cache cleanout search, and we do a MoveToFront pass only when about
to run a cleanout. In combination, these changes reduce the costs of
SearchCatCacheList and ReleaseCatCacheList from about 4.5% of pgbench
runtime to under 1%, according to my gprof results.
whenever we generate a new OID. This prevents occasional duplicate-OID
errors that can otherwise occur once the OID counter has wrapped around.
Duplicate relfilenode values are also checked for when creating new
physical files. Per my recent proposal.
ResourceOwner mechanism already released all reference counts for the
cache entries; therefore, we do not need to scan the catcache or relcache
at transaction end, unless we want to do it as a debugging crosscheck.
Do the crosscheck only in Assert mode. This is the same logic we had
previously installed in AtEOXact_Buffers to avoid overhead with large
numbers of shared buffers. I thought it'd be a good idea to do it here
too, in view of Kari Lavikka's recent report showing a real-world case
where AtEOXact_CatCache is taking a significant fraction of runtime.
and pg_auth_members. There are still many loose ends to finish in this
patch (no documentation, no regression tests, no pg_dump support for
instance). But I'm going to commit it now anyway so that Alvaro can
make some progress on shared dependencies. The catalog changes should
be pretty much done.
spotted by Qingqing Zhou. The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places. If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL. But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.
routines in the index's relcache entry, instead of doing a fresh fmgr_info
on every index access. We were already doing this for the index's opclass
support functions; not sure why we didn't think to do it for the AM
functions too. This supersedes the former method of caching (only)
amgettuple in indexscan scan descriptors; it's an improvement because the
function lookup can be amortized across multiple statements instead of
being repeated for each statement. Even though lookup for builtin
functions is pretty cheap, this seems to drop a percent or two off some
simple benchmarks.
memset() or MemSet() to a char *. For one, memset()'s first argument is
a void *, and further void * can be implicitly coerced to/from any other
pointer type.
which is neither needed by nor related to that header. Remove the bogus
inclusion and instead include the header in those C files that actually
need it. Also fix unnecessary inclusions and bad inclusion order in
tsearch2 files.
only one argument. (Per recent discussion, the option to accept multiple
arguments is pretty useless for user-defined types, and would be a likely
source of security holes if it was used.) Simplify call sites of
output/send functions to not bother passing more than one argument.
whose keys are OIDs. The only one that looks particularly performance
critical is the relcache hashtable, but as long as we've got the function
we may as well use it wherever it's applicable.
indexes. Replace all heap_openr and index_openr calls by heap_open
and index_open. Remove runtime lookups of catalog OID numbers in
various places. Remove relcache's support for looking up system
catalogs by name. Bulky but mostly very boring patch ...
indexes. Extend the macros in include/catalog/*.h to carry the info
about hand-assigned OIDs, and adjust the genbki script and bootstrap
code to make the relations actually get those OIDs. Remove the small
number of RelOid_pg_foo macros that we had in favor of a complete
set named like the catname.h and indexing.h macros. Next phase will
get rid of internal use of names for looking up catalogs and indexes;
but this completes the changes forcing an initdb, so it looks like a
good place to commit.
Along the way, I made the shared relations (pg_database etc) not be
'bootstrap' relations any more, so as to reduce the number of hardwired
entries and simplify changing those relations in future. I'm not
sure whether they ever really needed to be handled as bootstrap
relations, but it seems to work fine to not do so now.
into indexscans on matching indexes. For the moment, it only handles
int4 and text datatypes; next step is to add a column to pg_aggregate
so that all MIN/MAX aggregates can be handled. Per my recent proposal.
change saves a great deal of space in pg_proc and its primary index,
and it eliminates the former requirement that INDEX_MAX_KEYS and
FUNC_MAX_ARGS have the same value. INDEX_MAX_KEYS is still embedded
in the on-disk representation (because it affects index tuple header
size), but FUNC_MAX_ARGS is not. I believe it would now be possible
to increase FUNC_MAX_ARGS at little cost, but haven't experimented yet.
There are still a lot of vestigial references to FUNC_MAX_ARGS, which
I will clean up in a separate pass. However, getting rid of it
altogether would require changing the FunctionCallInfoData struct,
and I'm not sure I want to buy into that.
really ought to run before canonicalize_qual, because it can now produce
forms that canonicalize_qual knows how to improve (eg, NOT clauses).
Also, because eval_const_expressions already knows about flattening
nested ANDs and ORs into N-argument form, the initial flatten_andors
pass in canonicalize_qual is now completely redundant and can be
removed. This doesn't save a whole lot of code, but the time and
palloc traffic eliminated is a useful gain on large expression trees.
when open references remain during normal cleanup of a resource owner.
This restores the system's ability to warn about leaks to what it was
before 8.0. Not really a user-level bug, but helpful for development.
number of palloc calls. This has a salutory impact on plpgsql operations
with record variables (which create and destroy tupdescs constantly)
and probably helps a bit in some other cases too.
so that we can get the size of a shared inval message back down to what it
was in 7.4 (and simplify the logic too). Phase 2 of fixing the
'SMgrRelation hashtable corrupted' problem.
is the minimum required fix. I want to look next at taking advantage of
it by simplifying the message semantics in the shared inval message queue,
but that part can be held over for 8.1 if it turns out too ugly.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
(rd_att) field of a nailed-in-cache relcache entry. This fixes the bug
reported by Alvaro 8-Dec-2004; I believe it probably also explains
Grant Finnemore's report of 10-Sep-2004.
In an unrelated change in the same file, put back 7.4's response to
failure to rename() the relcache init file, ie, unlink the useless
temp file. I did not put back the warning message, since there might
actually be some reason not to have that.
clause implicitly whenever one is not given explicitly. Remove concept
of a schema having an associated tablespace, and simplify the rules for
selecting a default tablespace for a table or index. It's now just
(a) explicit TABLESPACE clause; (b) default_tablespace if that's not an
empty string; (c) database's default. This will allow pg_dump to use
SET commands instead of tablespace clauses to determine object locations
(but I didn't actually make it do so). All per recent discussions.
to make life cushy for the JDBC driver. Centralize the decision-making
that affects this by inventing a get_type_func_class() function, rather
than adding special cases in half a dozen places.
(1) Replace while loop with the new forboth() construct in
parser/analyze.c
(2) Replace lcons() with lappend() in SearchCatCacheList(). Since these
now have the same performance, there is no reason to prefer lcons() in
this case, and using lappend() leads to cleaner code.
(3) Improve the name of the second parameter to for_each_cell()
as per recent discussions. Invent SubTransactionIds that are managed like
CommandIds (ie, counter is reset at start of each top transaction), and
use these instead of TransactionIds to keep track of subtransaction status
in those modules that need it. This means that a subtransaction does not
need an XID unless it actually inserts/modifies rows in the database.
Accordingly, don't assign it an XID nor take a lock on the XID until it
tries to do that. This saves a lot of overhead for subtransactions that
are only used for error recovery (eg plpgsql exceptions). Also, arrange
to release a subtransaction's XID lock as soon as the subtransaction
exits, in both the commit and abort cases. This avoids holding many
unique locks after a long series of subtransactions. The price is some
additional overhead in XactLockTableWait, but that seems acceptable.
Finally, restructure the state machine in xact.c to have a more orthogonal
set of states for subtransactions.
Asserts would lead to a server core dump if an error occurred while
trying to abort a failed subtransaction (thereby leading to re-execution
of whatever parts of AbortSubTransaction had already run). This of course
does not prevent such an error from creating an infinite loop, but at
least we don't make the situation worse. Responds to an open item on
the subtransactions to-do list.
relcache entries. Also, change TransactionIdIsCurrentTransactionId()
so that if consulted during transaction abort, it will not say that
the aborted xact is still current. (It would be better to ensure that
it's never called at all during abort, but I'm not sure we can easily
guarantee that.) In combination, these fix a crash we have seen
occasionally during parallel regression tests of 8.0.
password/group files. Also allow read-only subtransactions of a read-write
parent, but not vice versa. These are the reasonably noncontroversial
parts of Alvaro's recent mop-up patch, plus further work on large objects
to minimize use of the TopTransactionResourceOwner.
keep track of portal-related resources separately from transaction-related
resources. This allows cursors to work in a somewhat sane fashion with
nested transactions. For now, cursor behavior is non-subtransactional,
that is a cursor's state does not roll back if you abort a subtransaction
that fetched from the cursor. We might want to change that later.
performance front, but with feature freeze upon us I think it's time to
drive a stake in the ground and say that this will be in 7.5.
Alvaro Herrera, with some help from Tom Lane.
should recognize 'foo.*' when the star appears in A_Indirection, not only
in ColumnRef. This allows 'SELECT something.*' to do what the user
expects when the something is an expression yielding a row.
There are various things left to do: contrib dbsize and oid2name modules
need work, and so does the documentation. Also someone should think about
COMMENT ON TABLESPACE and maybe RENAME TABLESPACE. Also initlocation is
dead, it just doesn't know it yet.
Gavin Sherry and Tom Lane.
of a composite type to get that type's OID as their second parameter,
in place of typelem which is useless. The actual changes are mostly
centralized in getTypeInputInfo and siblings, but I had to fix a few
places that were fetching pg_type.typelem for themselves instead of
using the lsyscache.c routines. Also, I renamed all the related variables
from 'typelem' to 'typioparam' to discourage people from assuming that
they necessarily contain array element types.
1. Solve the problem of not having TOAST references hiding inside composite
values by establishing the rule that toasting only goes one level deep:
a tuple can contain toasted fields, but a composite-type datum that is
to be inserted into a tuple cannot. Enforcing this in heap_formtuple
is relatively cheap and it avoids a large increase in the cost of running
the tuptoaster during final storage of a row.
2. Fix some interesting problems in expansion of inherited queries that
reference whole-row variables. We never really did this correctly before,
but it's now relatively painless to solve by expanding the parent's
whole-row Var into a RowExpr() selecting the proper columns from the
child.
If you dike out the preventive check in CheckAttributeType(),
composite-type columns now seem to actually work. However, we surely
cannot ship them like this --- without I/O for composite types, you
can't get pg_dump to dump tables containing them. So a little more
work still to do.
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.
costing us lots more to maintain than it was worth. On shared tables
it was of exactly zero benefit because we couldn't trust it to be
up to date. On temp tables it sometimes saved an lseek, but not often
enough to be worth getting excited about. And the real problem was that
we forced an lseek on every relcache flush in order to update the field.
So all in all it seems best to lose the complexity.
modify. Also fix a passel of problems with ALTER TABLE CLUSTER ON:
failure to check that the index is safe to cluster on (or even belongs
to the indicated rel, or even exists), and failure to broadcast a relcache
flush event when changing an index's state.
results with tuples as ordinary varlena Datums. This commit does not
in itself do much for us, except eliminate the horrid memory leak
associated with evaluation of whole-row variables. However, it lays the
groundwork for allowing composite types as table columns, and perhaps
some other useful features as well. Per my proposal of a few days ago.
* Changes incorrect CYGWIN defines to __CYGWIN__
* Some localtime returns NULL checks (when unchecked cause SEGVs under
Win32
regression tests)
* Rationalized CreateSharedMemoryAndSemaphores and
AttachSharedMemoryAndSemaphores (Bruce, I finally remembered to do it);
requires attention.
Claudio Natoli
the relcache, and so the notion of 'blind write' is gone. This should
improve efficiency in bgwriter and background checkpoint processes.
Internal restructuring in md.c to remove the not-very-useful array of
MdfdVec objects --- might as well just use pointers.
Also remove the long-dead 'persistent main memory' storage manager (mm.c),
since it seems quite unlikely to ever get resurrected.
about whether it is applied before or after eval_const_expressions().
I believe there were some corner cases where the system would fail to
recognize that a partial index is applicable because of the previous
inconsistency. Store normal rather than 'implicit AND' representations
of constraints and index predicates in the catalogs.
initdb forced due to representation change of constraints/predicates.
and hash bucket-size estimation. Issue has been there awhile but is more
critical in 7.4 because it affects varchar columns. Per report from
Greg Stark.
pghackers proposal of 8-Nov. All the existing cross-type comparison
operators (int2/int4/int8 and float4/float8) have appropriate support.
The original proposal of storing the right-hand-side datatype as part of
the primary key for pg_amop and pg_amproc got modified a bit in the event;
it is easier to store zero as the 'default' case and only store a nonzero
when the operator is actually cross-type. Along the way, remove the
long-since-defunct bigbox_ops operator class.
Remove the 'strategy map' code, which was a large amount of mechanism
that no longer had any use except reverse-mapping from procedure OID to
strategy number. Passing the strategy number to the index AM in the
first place is simpler and faster.
This is a preliminary step in planned support for cross-datatype index
operations. I'm committing it now since the ScanKeyEntryInitialize()
API change touches quite a lot of files, and I want to commit those
changes before the tree drifts under me.
with required outer parentheses. Breakage seems to be leftover from
domain-constraint patches. This could be smarter about suppressing
extra parens, but at this stage of the release cycle I want certainty
not cuteness.
now able to cope with assigning new relfilenode values to nailed-in-cache
indexes, so they can be reindexed using the fully crash-safe method. This
leaves only shared system indexes as special cases. Remove the 'index
deactivation' code, since it provides no useful protection in the shared-
index case. Require reindexing of shared indexes to be done in standalone
mode, but remove other restrictions on REINDEX. -P (IgnoreSystemIndexes)
now prevents using indexes for lookups, but does not disable index updates.
It is therefore safe to allow from PGOPTIONS. Upshot: reindexing system catalogs
can be done without a standalone backend for all cases except
shared catalogs.
datatype by array_eq and array_cmp; use this to solve problems with memory
leaks in array indexing support. The parser's equality_oper and ordering_oper
routines also use the cache. Change the operator search algorithms to look
for appropriate btree or hash index opclasses, instead of assuming operators
named '<' or '=' have the right semantics. (ORDER BY ASC/DESC now also look
at opclasses, instead of assuming '<' and '>' are the right things.) Add
several more index opclasses so that there is no regression in functionality
for base datatypes. initdb forced due to catalog additions.
target columns in INSERT and UPDATE targetlists. Don't rely on resname
to be accurate in ruleutils, either. This fixes bug reported by
Donald Fraser, in which renaming a column referenced in a rule did not
work very well.
It also works to create a non-polymorphic aggregate from polymorphic
functions, should you want to do that. Regression test added, docs still
lacking. By Joe Conway, with some kibitzing from Tom Lane.
comparison functions), replacing the highly bogus bitwise array_eq. Create
a btree index opclass for ANYARRAY --- it is now possible to create indexes
on array columns.
Arrange to cache the results of catalog lookups across multiple array
operations, instead of repeating the lookups on every call.
Add string_to_array and array_to_string functions.
Remove singleton_array, array_accum, array_assign, and array_subscript
functions, since these were for proof-of-concept and not intended to become
supported functions.
Minor adjustments to behavior in some corner cases with empty or
zero-dimensional arrays.
Joe Conway (with some editorializing by Tom Lane).
specific hash functions used by hash indexes, rather than the old
not-datatype-aware ComputeHashFunc routine. This makes it safe to do
hash joining on several datatypes that previously couldn't use hashing.
The sets of datatypes that are hash indexable and hash joinable are now
exactly the same, whereas before each had some that weren't in the other.
of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects). This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up. Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
blanks, in hopes of reducing the surprise factor for newbies. Remove
redundant operators for VARCHAR (it depends wholly on TEXT operations now).
Clean up resolution of ambiguous operators/functions to avoid surprising
choices for domains: domains are treated as equivalent to their base types
and binary-coercibility is no longer considered a preference item when
choosing among multiple operators/functions. IsBinaryCoercible now correctly
reflects the notion that you need *only* relabel the type to get from type
A to type B: that is, a domain is binary-coercible to its base type, but
not vice versa. Various marginal cleanup, including merging the essentially
duplicate resolution code in parse_func.c and parse_oper.c. Improve opr_sanity
regression test to understand about binary compatibility (using pg_cast),
and fix a couple of small errors in the catalogs revealed thereby.
Restructure "special operator" handling to fetch operators via index opclasses
rather than hardwiring assumptions about names (cleans up the pattern_ops
stuff a little).
This makes no difference for existing uses, but allows SelectSortFunction()
and pred_test_simple_clause() to use indexscans instead of seqscans to
locate entries for a particular operator in pg_amop. Better yet, they can
use the SearchSysCacheList() API to cache the search results.
expressions, ARRAY(sub-SELECT) expressions, some array functions.
Polymorphic functions using ANYARRAY/ANYELEMENT argument and return
types. Some regression tests in place, documentation is lacking.
Joe Conway, with some kibitzing from Tom Lane.
them as arrays of the internal datatype. This requires treating the
stavalues columns as 'anyarray' rather than 'text[]', which is not 100%
kosher but seems to work fine for the purposes we need for pg_statistic.
Perhaps in the future 'anyarray' will be allowed more generally.
rid of the assumption that sizeof(Oid)==sizeof(int). This is one small
step towards someday supporting 8-byte OIDs. For the moment, it doesn't
do much except get rid of a lot of unsightly casts.
startup, not in the parser; this allows ALTER DOMAIN to work correctly
with domain constraint operations stored in rules. Rod Taylor;
code review by Tom Lane.
containing a volatile function), rather than only on 'Var = Var' clauses
as before. This makes it practical to do flatten_join_alias_vars at the
start of planning, which in turn eliminates a bunch of klugery inside the
planner to deal with alias vars. As a free side effect, we now detect
implied equality of non-Var expressions; for example in
SELECT ... WHERE a.x = b.y and b.y = 42
we will deduce a.x = 42 and use that as a restriction qual on a. Also,
we can remove the restriction introduced 12/5/02 to prevent pullup of
subqueries whose targetlists contain sublinks.
Still TODO: make statistical estimation routines in selfuncs.c and costsize.c
smarter about expressions that are more complex than plain Vars. The need
for this is considerably greater now that we have to be able to estimate
the suitability of merge and hash join techniques on such expressions.
disallowed by CREATE TABLE (eg, pseudo-types); also disallow these types
from being introduced by the range-function syntax. While at it, allow
CREATE TABLE to create zero-column tables, per recent pghackers discussion.
I am back-patching this into 7.3 since failure to disallow pseudo-types
is arguably a security hole.
given any malloc block until something is first allocated in it; but
thereafter, MemoryContextReset won't release that first malloc block.
This preserves the quick-reset property of the original policy, without
forcing 8K to be allocated to every context whether any of it is ever
used or not. Also, remove some more no-longer-needed explicit freeing
during ExecEndPlan.
execution state trees, and ExecEvalExpr takes an expression state tree
not an expression plan tree. The plan tree is now read-only as far as
the executor is concerned. Next step is to begin actually exploiting
this property.
('SELECT expression') inline, like macros, during the constant-folding
phase of planning. The actual expansion is not difficult, but checking
that we're not changing the semantics of the call turns out to be more
subtle than one might think; in particular must pay attention to
permissions issues, strictness, and volatility.
The code was not making TupleConstr structs for such catalogs in
several places; with the consequence that the not-null constraint
wasn't actually enforced. With this change,
INSERT INTO pg_proc VALUES('sdf');
generates a 'Fail to add null value' error instead of a core dump.
query that uses it. This ensures that triggers will be applied consistently
throughout a query even if someone commits changes to the relation's
pg_class.reltriggers field meanwhile. Per crash report from Laurette Cisneros.
While at it, simplify memory management in relcache.c, which no longer
needs the old hack to try to keep trigger info in the same place over
a relcache entry rebuild. (Should try to fix rd_att and rewrite-rule
access similarly, someday.) And make RelationBuildTriggers simpler and
more robust by making it build the trigdesc in working memory and then
CopyTriggerDesc() into cache memory.
even when dealing with a nailed-in-cache relation; otherwise, following
VACUUM truncation of a system catalog, other backends might have
unreasonably large values of these fields.
composite types. Add a couple more lsyscache.c routines to support this,
and make use of them in some other places that were doing lookups the
hard way.
to be flexible about assignment casts without introducing ambiguity in
operator/function resolution. Introduce a well-defined promotion hierarchy
for numeric datatypes (int2->int4->int8->numeric->float4->float8).
Change make_const to initially label numeric literals as int4, int8, or
numeric (never float8 anymore).
Explicitly mark Func and RelabelType nodes to indicate whether they came
from a function call, explicit cast, or implicit cast; use this to do
reverse-listing more accurately and without so many heuristics.
Explicit casts to char, varchar, bit, varbit will truncate or pad without
raising an error (the pre-7.2 behavior), while assigning to a column without
any explicit cast will still raise an error for wrong-length data like 7.3.
This more nearly follows the SQL spec than 7.2 behavior (we should be
reporting a 'completion condition' in the explicit-cast cases, but we have
no mechanism for that, so just do silent truncation).
Fix some problems with enforcement of typmod for array elements;
it didn't work at all in 'UPDATE ... SET array[n] = foo', for example.
Provide a generalized array_length_coerce() function to replace the
specialized per-array-type functions that used to be needed (and were
missing for NUMERIC as well as all the datetime types).
Add missing conversions int8<->float4, text<->numeric, oid<->int8.
initdb forced.
(overlaying low byte of page size) and add HEAP_HASOID bit to t_infomask,
per earlier discussion. Simplify scheme for overlaying fields in tuple
header (no need for cmax to live in more than one place). Don't try to
clear infomask status bits in tqual.c --- not safe to do it there. Don't
try to force output table of a SELECT INTO to have OIDs, either. Get rid
of unnecessarily complex three-state scheme for TupleDesc.tdhasoids, which
has already caused one recent failure. Improve documentation.
type for runtime constraint checks, instead of misusing the parse-time
Constraint node for the purpose. Fix some damage introduced into type
coercion logic; in particular ensure that a coerced expression tree will
read out the correct result type when inspected (patch had broken some
RelabelType cases). Enforce domain NOT NULL constraints against columns
that are omitted from an INSERT.
array header, and to compute sizing and alignment of array elements
the same way normal tuple access operations do --- viz, using the
tupmacs.h macros att_addlength and att_align. This makes the world
safe for arrays of cstrings or intervals, and should make it much
easier to write array-type-polymorphic functions; as examples see
the cleanups of array_out and contrib/array_iterator. By Joe Conway
and Tom Lane.
with OPAQUE, as per recent pghackers discussion. I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...
The local buffer manager is no longer used for newly-created relations
(unless they are TEMP); a new non-TEMP relation goes through the shared
bufmgr and thus will participate normally in checkpoints. But TEMP relations
use the local buffer manager throughout their lifespan. Also, operations
in TEMP relations are not logged in WAL, thus improving performance.
Since it's no longer necessary to fsync relations as they move out of the
local buffers into shared buffers, quite a lot of smgr.c/md.c/fd.c code
is no longer needed and has been removed: there's no concept of a dirty
relation anymore in md.c/fd.c, and we never fsync anything but WAL.
Still TODO: improve local buffer management algorithms so that it would
be reasonable to increase NLocBuffer.
hardwired lists of index names for each catalog, use the relcache's
mechanism for caching lists of OIDs of indexes of any table. This
reduces the common case of updating system catalog indexes to a single
line, makes it much easier to add a new system index (in fact, you
can now do so on-the-fly if you want to), and as a nice side benefit
improves performance a little. Per recent pghackers discussion.
of functions returning domain types, update documentation for typtype,
move get_typtype to lsyscache.c (actually, resurrect the old version),
add defense against creating pseudo-typed table columns, fix some
bogus list-parsing in grammar. Issues remain with respect to alias
handling and type checking; Joe is on those.
in the relcache. It's rather silly that we have reference count leak
checks in bufmgr and in catcache, but not in relcache which will normally
have many fewer entries. Chris K-L would have caught at least one bug
in his recent DROP patch if he'd had this.
code review by Tom Lane. Remaining issues: functions that take or
return tuple types are likely to break if one drops (or adds!)
a column in the table defining the type. Need to think about what
to do here.
Along the way: some code review for recent COPY changes; mark system
columns attnotnull = true where appropriate, per discussion a month ago.
bitmap, if present).
Per Tom Lane's suggestion the information whether a tuple has an oid
or not is carried in the tuple descriptor. For debugging reasons
tdhasoid is of type char, not bool. There are predefined values for
WITHOID, WITHOUTOID and UNDEFOID.
This patch has been generated against a cvs snapshot from last week
and I don't expect it to apply cleanly to current sources. While I
post it here for public review, I'm working on a new version against a
current snapshot. (There's been heavy activity recently; hope to
catch up some day ...)
This is a long patch; if it is too hard to swallow, I can provide it
in smaller pieces:
Part 1: Accessor macros
Part 2: tdhasoid in TupDesc
Part 3: Regression test
Part 4: Parameter withoid to heap_addheader
Part 5: Eliminate t_oid from HeapTupleHeader
Part 2 is the most hairy part because of changes in the executor and
even in the parser; the other parts are straightforward.
Up to part 4 the patched postmaster stays binary compatible to
databases created with an unpatched version. Part 5 is small (100
lines) and finally breaks compatibility.
Manfred Koizar
extension to create binary compatible casts. Includes dependency tracking
as well.
pg_proc.proimplicit is now defunct, but will be removed in a separate
commit.
pg_dump provides a migration path from the previous scheme to declare
casts. Dumping binary compatible casts is currently impossible, though.
pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY
constraints all have real live entries in pg_constraint. pg_depend
exists, and RESTRICT/CASCADE options work on most kinds of DROP;
however, pg_depend is not yet very well populated with dependencies.
(Most of the ones that are present at this point just replace formerly
hardwired associations, such as the implicit drop of a relation's pg_type
entry when the relation is dropped.) Need to add more logic to create
dependency entries, improve pg_dump to dump constraints in place of
indexes and triggers, and add some regression tests.
This is the first cut toward CREATE CONVERSION/DROP CONVERSION implementaion.
The commands can now add/remove tuples to the new pg_conversion system
catalog, but that's all. Still need work to make them actually working.
Documentations, regression tests also need work.
are managed as per request.
Moved from merging with table attributes to applying themselves during
coerce_type() and coerce_type_typmod.
Regression tests altered to test the cast() scenarios.
Rod Taylor
returns-set boolean field in Func and Oper nodes. This allows cleaner,
more reliable tests for expressions returning sets in the planner and
parser. For example, a WHERE clause returning a set is now detected
and complained of in the parser, not only at runtime.
pg_database, pg_shadow, pg_group, all of which now have potentially-long
fields. Along the way, get rid of SharedSystemRelationNames list: shared
rels are now identified in their include/pg_catalog/*.h files by a
BKI_SHARED_RELATION macro, while indexes and toast rels inherit sharedness
automatically from their parent table. Fix some bugs with failure to detoast
pg_group.grolist during ALTER GROUP.
messages more uniform and internationalizable: the global array
aclcheck_error_strings[] is gone in favor of a subroutine
aclcheck_error(). Partial implementation of namespace-related
permission checks --- not all done yet.
per pghackers discussion. Add some more typsanity tests, and clean
up some problems exposed thereby (broken or missing array types for
some built-in types). Also, clean up loose ends from unknownin/out
patch.
different privilege bits (might as well make use of the space we were
wasting on padding). EXECUTE and USAGE bits for procedures, languages
now are separate privileges instead of being overlaid on SELECT. Add
privileges for namespaces and databases. The GRANT and REVOKE commands
work for these object types, but we don't actually enforce the privileges
yet...
(tgrelid, tgname). This provides an additional check on trigger name
uniqueness per-table (which was already enforced by the code anyway).
With this change, RelationBuildTriggers will read the triggers in
order by tgname, since it's scanning using this index. Since a
predictable trigger ordering has been requested for some time, document
this behavior as a feature. Also document that rules fire in name
order, since yesterday's changes to pg_rewrite indexing cause that too.
DROP RULE and COMMENT ON RULE syntax adds an 'ON tablename' clause,
similar to TRIGGER syntaxes. To allow loading of existing pg_dump
files containing COMMENT ON RULE, the COMMENT code will still accept
the old syntax --- but only if the target rulename is unique across
the whole database.
an 'opclass owner' column in pg_opclass. Nothing is done with it at
present, but since there are plans to invent a CREATE OPERATOR CLASS
command soon, we'll probably want DROP OPERATOR CLASS too, which
suggests that a notion of ownership would be a good idea.
qualified operator names directly, for example CREATE OPERATOR myschema.+
( ... ). To qualify an operator name in an expression you need to write
OPERATOR(myschema.+) (thanks to Peter for suggesting an escape hatch).
I also took advantage of having to reformat pg_operator to fix something
that'd been bugging me for a while: mergejoinable operators should have
explicit links to the associated cross-data-type comparison operators,
rather than hardwiring an assumption that they are named < and >.
entries, per pghackers discussion. This fixes aggregates to live in
namespaces, and also simplifies/speeds up lookup in parse_func.c.
Also, add a 'proimplicit' flag to pg_proc that controls whether a type
coercion function may be invoked implicitly, or only explicitly. The
current settings of these flags are more permissive than I would like,
but we will need to debate and refine the behavior; for now, I avoided
breaking regression tests as much as I could.
volatile), rather than the old cachable/noncachable distinction. This
allows indexscan optimizations in many places where we formerly didn't.
Also, add a pronamespace column to pg_proc (it doesn't do anything yet,
however).
in schemas other than the system namespace; however, there's no search
path yet, and not all operations work yet on tables outside the system
namespace.
addRangeTableEntry calls. Remove relname field from RTEs, since
it will no longer be a useful unique identifier of relations;
we want to encourage people to rely on the relation OID instead.
Further work on dumping qual expressions in EXPLAIN, too.
objects to be privilege-checked. Some change in their APIs would be
necessary no matter what in the schema environment, and simply getting
rid of the name-based interface entirely seems like the best way.
PostgreSQL. This hash function replaces the one used by hash indexes and
the catalog cache. Hash joins use a different, relatively poor-quality
hash function, but I'll fix that later.
As suggested by Tom Lane, this patch also changes the size of the fixed
hash table used by the catalog cache to be a power-of-2 (instead of a
prime: I chose 256 instead of 257). This allows the catcache to lookup
hash buckets using a simple bitmask. This should improve the performance
of the catalog cache slightly, since the previous method (modulo a
prime) was slow.
In my tests, this improves the performance of hash indexes by between 4%
and 8%; the performance when using btree indexes or seqscans is
basically unchanged.
Neil Conway <neilconway@rogers.com>
- domain.patch -> source patch against pgsql in cvs
- drop_domain.sgml and create_domain.sgml -> New doc/src/sgml/ref docs
- dominfo.txt -> basic domain related queries I used for testing
[ ADDED TO /doc]
Enables domains of array elements -> CREATE DOMAIN dom int4[3][2];
Uses a typbasetype column to describe the origin of the domain.
Copies data to attnotnull rather than processing in execMain().
Some documentation differences from earlier.
If this is approved, I'll start working on pg_dump, and a \dD <domain>
option in psql, and regression tests. I don't really feel like doing
those until the system table structure settles for pg_type.
CHECKS when added, will also be copied to to the table attributes. FK
Constraints (if I ever figure out how) will be done similarly. Both
will lbe handled by MergeDomainAttributes() which is called shortly
before MergeAttributes().
Rod Taylor
o Change all current CVS messages of NOTICE to WARNING. We were going
to do this just before 7.3 beta but it has to be done now, as you will
see below.
o Change current INFO messages that should be controlled by
client_min_messages to NOTICE.
o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc.
to always go to the client.
o Remove INFO from the client_min_messages options and add NOTICE.
Seems we do need three non-ERROR elog levels to handle the various
behaviors we need for these messages.
Regression passed.
speed up repetitive failed searches; per pghackers discussion in late
January. inval.c logic substantially simplified, since we can now treat
inserts and deletes alike as far as inval events are concerned. Some
repair work needed in heap_create_with_catalog, which turns out to have
been doing CommandCounterIncrement at a point where the new relation has
non-self-consistent catalog entries. With the new inval code, that
resulted in assert failures during a relcache entry rebuild.
now just below FATAL in server_min_messages. Added more text to
highlight ordering difference between it and client_min_messages.
---------------------------------------------------------------------------
REALLYFATAL => PANIC
STOP => PANIC
New INFO level the prints to client by default
New LOG level the prints to server log by default
Cause VACUUM information to print only to the client
NOTICE => INFO where purely information messages are sent
DEBUG => LOG for purely server status messages
DEBUG removed, kept as backward compatible
DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added
DebugLvl removed in favor of new DEBUG[1-5] symbols
New server_min_messages GUC parameter with values:
DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC
New client_min_messages GUC parameter with values:
DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC
Server startup now logged with LOG instead of DEBUG
Remove debug_level GUC parameter
elog() numbers now start at 10
Add test to print error message if older elog() values are passed to elog()
Bootstrap mode now has a -d that requires an argument, like postmaster
both input streams to the end. If one variable's range is much less
than the other, an indexscan-based merge can win by not scanning all
of the other table. Per example from Reinhard Max.
hashname() and reduce the penalty incured when NAMEDATALEN is increased.
I posted this to -hackers a couple days ago, and there haven't been any
major complaints. It passes the regression tests. See -hackers for more
discussion, as well as the suggestion from Tom Lane on which this patch
is based.
Unless anyone sees any problems, please apply for 7.3.
Cheers,
Neil Conway
Improve 'pg_internal.init' relcache entry preload mechanism so that it is
safe to use for all system catalogs, and arrange to preload a realistic
set of system-catalog entries instead of only the three nailed-in-cache
indexes that were formerly loaded this way. Fix mechanism for deleting
out-of-date pg_internal.init files: this must be synchronized with transaction
commit, not just done at random times within transactions. Drive it off
relcache invalidation mechanism so that no special-case tests are needed.
Cache additional information in relcache entries for indexes (their pg_index
tuples and index-operator OIDs) to eliminate repeated lookups. Also cache
index opclass info at the per-opclass level to avoid repeated lookups during
relcache load.
Generalize 'systable scan' utilities originally developed by Hiroshi,
move them into genam.c, use in a number of places where there was formerly
ugly code for choosing either heap or index scan. In particular this allows
simplification of the logic that prevents infinite recursion between syscache
and relcache during startup: we can easily switch to heapscans in relcache.c
when and where needed to avoid recursion, so IndexScanOK becomes simpler and
does not need any expensive initialization.
Eliminate useless opening of a heapscan data structure while doing an indexscan
(this saves an mdnblocks call and thus at least one kernel call).
This saves one open file descriptor per backend, and avoids an
annoying NOTICE on Cygwin (which has trouble deleting open files).
Bug appears to date back to original coding of init_irels, circa 1992.
This seems the right thing for most usages, but I notice two places
where it is the wrong thing. One is that the default permissions on
TOAST rels should be no-access, not world-readable; the other is that
PrepareForTupleInvalidation doesn't really need to spend time looking
at tuples of TOAST relations.
lookup info in the relcache for index access method support functions.
This makes a huge difference for dynamically loaded support functions,
and should save a few cycles even for built-in ones. Also tweak dfmgr.c
so that load_external_function is called only once, not twice, when
doing fmgr_info for a dynamically loaded function. All per performance
gripe from Teodor Sigaev, 5-Oct-01.
readability. Bizarre '(long *) TRUE' return convention is gone,
in favor of just raising an error internally in dynahash.c when
we detect hashtable corruption. HashTableWalk is gone, in favor
of using hash_seq_search directly, since it had no hope of working
with non-LONGALIGNable datatypes. Simplify some other code that was
made undesirably grotty by promixity to HashTableWalk.
portability issues). Caller-visible data structures are now allocated
on MAXALIGN boundaries, allowing safe use of datatypes wider than 'long'.
Rejigger hash_create API so that caller specifies size of key and
total size of entry, not size of key and size of rest of entry.
This simplifies life considerably since each number is just a sizeof(),
and padding issues etc. are taken care of automatically.
Frank Miles 7-Sep-01. This is really just sticking a finger in the dike.
Frank's case works now, but we still couldn't support a recursive function
returning a set. Really need to restructure querytrees and execution
state so that the querytree is *read only*. We've run into this over and
over and over again ... it has to happen sometime soon.
If there's anyone out there who's actually using datatype-defined
default values, this will be an incompatible change in behavior ...
but the old behavior was so broken that I doubt anyone was using it.
buffer manager with 'pg_clog', a specialized access method modeled
on pg_xlog. This simplifies startup (don't need to play games to
open pg_log; among other things, OverrideTransactionSystem goes away),
should improve performance a little, and opens the door to recycling
commit log space by removing no-longer-needed segments of the commit
log. Actual recycling is not there yet, but I felt I should commit
this part separately since it'd still be useful if we chose not to
do transaction ID wraparound.
pgsql-hackers. pg_opclass now has a row for each opclass supported by each
index AM, not a row for each opclass name. This allows pg_opclass to show
directly whether an AM supports an opclass, and furthermore makes it possible
to store additional information about an opclass that might be AM-dependent.
pg_opclass and pg_amop now store "lossy" and "haskeytype" information that we
previously expected the user to remember to provide in CREATE INDEX commands.
Lossiness is no longer an index-level property, but is associated with the
use of a particular operator in a particular index opclass.
Along the way, IndexSupportInitialize now uses the syscaches to retrieve
pg_amop and pg_amproc entries. I find this reduces backend launch time by
about ten percent, at the cost of a couple more special cases in catcache.c's
IndexScanOK.
Initial work by Oleg Bartunov and Teodor Sigaev, further hacking by Tom Lane.
initdb forced.
default, but OIDS are removed from many system catalogs that don't need them.
Some interesting side effects: TOAST pointers are 20 bytes not 32 now;
pg_description has a three-column key instead of one.
Bugs fixed in passing: BINARY cursors work again; pg_class.relhaspkey
has some usefulness; pg_dump dumps comments on indexes, rules, and
triggers in a valid order.
initdb forced.
stub) into the rest of the system. Adopt a cleaner approach to preventing
deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to
select any page of the rel, and put the onus on it to lock both buffers
in a consistent order. Remove no-longer-needed isExtend hack from
API of ReleaseAndReadBuffer.
do anything yet, but it has the necessary connections to initialization
and so forth. Make some gestures towards allowing number of blocks in
a relation to be BlockNumber, ie, unsigned int, rather than signed int.
(I doubt I got all the places that are sloppy about it, yet.) On the
way, replace the hardwired NLOCKS_PER_XACT fudge factor with a GUC
variable.
SI messages now include the relevant database OID, so that operations
in one database do not cause useless cache flushes in backends attached
to other databases. Declare SI messages properly using a union, to
eliminate the former assumption that Oid is the same size as int or Index.
Rewrite the nearly-unreadable code in inval.c, and document it better.
Arrange for catcache flushes at end of command/transaction to happen before
relcache flushes do --- this avoids loading a new tuple into the catcache
while setting up new relcache entry, only to have it be flushed again
immediately.
CatalogCacheFlushRelation (formerly called SystemCacheRelationFlushed)
how to distinguish tuples it should flush from those it needn't; this
means a relcache flush event now only removes the catcache entries
it ought to, rather than zapping the caches completely as it used to.
Testing with the regression tests indicates that this considerably
improves the lifespan of catcache entries. Also, rearrange catcache
data structures so that the limit on number of cached tuples applies
globally across all the catcaches, rather than being per-catcache.
It was a little silly to have the same size limit on both, say,
pg_attribute caches and pg_am caches (there being only four possible
rows in the latter...). Doing LRU removal across all the caches
instead of locally in each one should reduce cache reload traffic
in the more heavily used caches and improve the efficiency of
cache memory use.
Tom Lane). For the moment, only the OID/name variants are provided.
I didn't force initdb, but the additions to the 'privileges' regress
test won't pass until you do one.
pg_database now has unique indexes on oid and on datname.
pg_shadow now has unique indexes on usename and on usesysid.
pg_am now has unique index on oid.
pg_opclass now has unique index on oid.
pg_amproc now has unique index on amid+amopclaid+amprocnum.
Remove pg_rewrite's unnecessary index on oid, delete unused RULEOID syscache.
Remove index on pg_listener and associated syscache for performance reasons
(caching rows that are certain to change before you need 'em again is
rather pointless).
Change pg_attrdef's nonunique index on adrelid into a unique index on
adrelid+adnum.
Fix various incorrect settings of pg_class.relisshared, make that the
primary reference point for whether a relation is shared or not.
IsSharedSystemRelationName() is now only consulted to initialize relisshared
during initial creation of tables and indexes. In theory we might now
support shared user relations, though it's not clear how one would get
entries for them into pg_class &etc of multiple databases.
Fix recently reported bug that pg_attribute rows created for an index all have
the same OID. (Proof that non-unique OID doesn't matter unless it's
actually used to do lookups ;-))
There's no need to treat pg_trigger, pg_attrdef, pg_relcheck as bootstrap
relations. Convert them into plain system catalogs without hardwired
entries in pg_class and friends.
Unify global.bki and template1.bki into a single init script postgres.bki,
since the alleged distinction between them was misleading and pointless.
Not to mention that it didn't work for setting up indexes on shared
system relations.
Rationalize locking of pg_shadow, pg_group, pg_attrdef (no need to use
AccessExclusiveLock where ExclusiveLock or even RowExclusiveLock will do).
Also, hold locks until transaction commit where necessary.
report on old-style functions invoked by RI triggers. We had a number of
other places that were being sloppy about which memory context FmgrInfo
subsidiary data will be allocated in. Turns out none of them actually
cause a problem in 7.1, but this is for arcane reasons such as the fact
that old-style triggers aren't supported anyway. To avoid getting burnt
later, I've restructured the trigger support so that we don't keep trigger
FmgrInfo structs in relcache memory. Some other related cleanups too:
it's not really necessary to call fmgr_info at all while setting up
the index support info in relcache entries, because those ScanKeyEntry
structs are never used to invoke the functions. This should speed up
relcache initialization a tiny bit.
collected by ANALYZE. Also, add some modest amount of intelligence to
guesses that are used for varlena columns in the absence of any ANALYZE
statistics. The 'width' reported by EXPLAIN is finally something less
than totally bogus for varlena columns ... and, in consequence, hashjoin
estimating should be a little better ...
a separate statement (though it can still be invoked as part of VACUUM, too).
pg_statistic redesigned to be more flexible about what statistics are
stored. ANALYZE now collects a list of several of the most common values,
not just one, plus a histogram (not just the min and max values). Random
sampling is used to make the process reasonably fast even on very large
tables. The number of values and histogram bins collected is now
user-settable via an ALTER TABLE command.
There is more still to do; the new stats are not being used everywhere
they could be in the planner. But the remaining changes for this project
should be localized, and the behavior is already better than before.
A not-very-related change is that sorting now makes use of btree comparison
routines if it can find one, rather than invoking '<' twice.
physical file has disappeared. There is no really good reason why
relcache should be opening the underlying file at all, AFAICS.
In any case we needn't raise a hard error here.
are now critical sections, so as to ensure die() won't interrupt us while
we are munging shared-memory data structures. Avoid insecure intermediate
states in some code that proc_exit will call, like palloc/pfree. Rename
START/END_CRIT_CODE to START/END_CRIT_SECTION, since that seems to be
what people tend to call them anyway, and make them be called with () like
a function call, in hopes of not confusing pg_indent.
I doubt that this is sufficient to make SIGTERM safe anywhere; there's
just too much code that could get invoked during proc_exit().
in per-entry sub-memory-context, where they were supposed to go, rather
than in CacheMemoryContext where the code was putting them. Must've
suffered a severe brain fade when I wrote this :-(
starting a new hashtable search no longer clobbers any other search
active anywhere in the system. Fix RelationCacheInvalidate() so that
it will not crash or go into an infinite loop if invoked recursively,
as for example by a second SI Reset message arriving while we are still
processing a prior one.
1. Distinguish cases where a Datum representing a tuple datatype is an OID
from cases where it is a pointer to TupleTableSlot, and make sure we use
the right typlen in each case.
2. Make fetchatt() and related code support 8-byte by-value datatypes on
machines where Datum is 8 bytes. Centralize knowledge of the available
by-value datatype sizes in two macros in tupmacs.h, so that this will be
easier if we ever have to do it again.
table that inherits from a temp table. Make sure the right things happen
if one creates a temp table, creates another temp that inherits from it,
then renames the first one. (Previously, system would end up trying to
delete the temp tables in the wrong order.)
both MULTIBYTE and TOAST prevent char(n) from being truly fixed-size.
Simplify and speed up fastgetattr() and index_getattr() macros by
eliminating special cases for attnum=1. It's just as fast to handle
the first attribute by presetting its attcacheoff to zero; so do that
instead when loading the tupledesc in relcache.c.
in pghackers list. Support for oldstyle internal functions is gone
(no longer needed, since conversion is complete) and pg_language entry
'internal' now implies newstyle call convention. pg_language entry
'newC' is gone; both old and newstyle dynamically loaded C functions
are now called language 'C'. A newstyle function must be identified
by an associated info routine. See src/backend/utils/fmgr/README.
maintained for each cache entry. A cache entry will not be freed until
the matching ReleaseSysCache call has been executed. This eliminates
worries about cache entries getting dropped while still in use. See
my posting to pg-hackers of even date for more info.
message about recursive use of a syscache. Also remove most of the
specialized indexscan routines in indexing.c --- it turns out that
catcache.c is perfectly able to perform the indexscan for itself,
in fact has already looked up all the information needed to do so!
This should be faster as well as needing far less boilerplate code.
(WAL logging for this is not done yet, however.) Clean up a number of really
crufty things that are no longer needed now that DROP behaves nicely. Make
temp table mapper do the right things when drop or rename affecting a temp
table is rolled back. Also, remove "relation modified while in use" error
check, in favor of locking tables at first reference and holding that lock
throughout the statement.
from bufmgr - it would be nice to have separate hash in smgr
for node <--> fd mappings, but for the moment it's easy to
add new hash to relcache.
Fixed small bug in xlog.c:ReadRecord.
for views. Views are now have a "relkind" of
RELKIND_VIEW instead of RELKIND_RELATION.
Also, views no longer have actual heap storage
files.
The following changes were made
1. CREATE VIEW sets the new relkind
2. The executor complains if a DELETE or
INSERT references a view.
3. DROP RULE complains if an attempt is made
to delete a view SELECT rule.
4. CREATE RULE "_RETmytable" AS ON SELECT TO mytable DO INSTEAD ...
1. checks to make sure mytable is empty.
2. sets the relkind to RELKIND_VIEW.
3. deletes the heap storage files.
5. LOCK myview is not allowed. :)
6. the regression test type_sanity was changed to
account for the new relkind value.
7. CREATE INDEX ON myview ... is not allowed.
8. VACUUM myview is not allowed.
VACUUM automatically skips views when do the entire
database.
9. TRUNCATE myview is not allowed.
THINGS LEFT TO THINK ABOUT
o pg_views
o pg_dump
o pgsql (\d \dv)
o Do we really want to be able to inherit from views?
o Is 'DROP TABLE myview' OK?
--
Mark Hollomon
=# create table t (id int4 unique);
NOTICE: CREATE TABLE/UNIQUE will create implicit index 't_id_key' for table 't'
=# begin;
query: drop table t;
NOTICE: Caution: DROP TABLE cannot be rolled back, so don't abort now
NOTICE: Caution: DROP INDEX cannot be rolled back, so don't abort now
=# rollback;
=# drop table t;
NOTICE: mdopen: couldn't open t: No such file or directory
NOTICE: RelationIdBuildRelation: smgropen(t): No such file or directory
NOTICE: mdopen: couldn't open t: No such file or directory
NOTICE: mdopen: couldn't open t: No such file or directory
NOTICE: mdopen: couldn't open t_id_key: No such file or directory
NOTICE: RelationIdBuildRelation: smgropen(t_id_key): No such file or directory
NOTICE: mdopen: couldn't open t: No such file or directory
NOTICE: RelationIdBuildRelation: smgropen(t): No such file or directory
NOTICE: mdopen: couldn't open t: No such file or directory
ERROR: cannot open relation t
for example, an SQL function can be used in a functional index. (I make
no promises about speed, but it'll work ;-).) Clean up and simplify
handling of functions returning sets.
right thing with variable-free clauses that contain noncachable functions,
such as 'WHERE random() < 0.5' --- these are evaluated once per
potential output tuple. Expressions that contain only Params are
now candidates to be indexscan quals --- for example, 'var = ($1 + 1)'
can now be indexed. Cope with RelabelType nodes atop potential indexscan
variables --- this oversight prevents 7.0.* from recognizing some
potentially indexscanable situations.
from Param nodes, per discussion a few days ago on pghackers. Add new
expression node type FieldSelect that implements the functionality where
it's actually needed. Clean up some other unused fields in Func nodes
as well.
NOTE: initdb forced due to change in stored expression trees for rules.
that giving pg_proc a toast table required solving the same problems
we'd have to solve for pg_class --- pg_proc is one of the relations
that gets bootstrapped in relcache.c. Solution is to go back at the
end of initialization and read in the *real* pg_class row to replace
the phony entry created by formrdesc(). This should work as long as
there's no need to touch any toasted values during initialization,
which seems a reasonable assumption.
Although I did not add a toast-table for every single system table
with a varlena attribute, I believe that it would work to just do
ALTER TABLE pg_class CREATE TOAST TABLE. So anyone who's really
intent on having several thousand ACL entries for a rel could do it.
NOTE: I didn't force initdb, but you must do one to see the effects
of this patch.
(Sorry, couldn't help it...)
Removed type filename as well, since it's unused and probably useless.
INITDB FORCED, because pg_rewrite columns are now plain text again.
pass-by-ref data types --- eg, an index on lower(textfield) --- no longer
leak memory during index creation or update. Clean up a lot of redundant
code ... did you know that copy, vacuum, truncate, reindex, extend index,
and bootstrap each basically duplicated the main executor's logic for
extracting information about an index and preparing index entries?
Functional indexes should be a little faster now too, due to removal
of repeated function lookups.
CREATE INDEX 'opt_type' clause is deimplemented by these changes,
but I haven't removed it from the parser yet (need to merge with
Thomas' latest change set first).
memory contexts. Currently, only leaks in expressions executed as
quals or projections are handled. Clean up some old dead cruft in
executor while at it --- unused fields in state nodes, that sort of thing.
Don't go through pg_exec_query_dest(), but directly to the execution
routines. Also, extend parameter lists so that there's no need to
change the global setting of allowSystemTableMods, a hack that was
certain to cause trouble in the event of any error.
entry that has rules. This allows us to release the rule parsetrees
on relcache flush without needing a working freeObject() routine.
Formerly, the rule trees were leaked permanently at relcache flush.
Also, clean up handling of rule creation and deletion --- there was
not sufficient locking of the relation being modified, and there was
no reliable notification of other backends that a relcache reload
was needed. Also, clean up relcache.c code so that scans of system
tables needed to load a relcache entry are done in the caller's
memory context, not in CacheMemoryContext. This prevents any
un-pfreed memory from those scans from becoming a permanent memory
leak.
for details). It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably. A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing. Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.
to apply the tempname->realname mapping to type name lookup as well
as relation name lookup, else the type tuple will not be found when
wanted. This fixes bugs like this one:
create temp table foo (f1 int);
select foo.f2 from foo;
ERROR: Unable to locate type name 'foo' in catalog
are opened in a consistent order by different backends (I ordered them
by index OID because that's easy, but any other consistent order would
do as well). This avoids potential deadlock for index types that we
acquire exclusive locks on ... ie, rtree.
entries now for int8 and network hash indexes. int24_ops and int42_ops
are gone. pg_opclass no longer contains multiple entries claiming to be
the default opclass for the same datatype. opr_sanity regress test
extended to catch errors like these in the future.
materialized tupleset is small enough) instead of a temporary relation.
This was something I was thinking of doing anyway for performance, and Jan
says he needs it for TOAST because he doesn't want to cope with toasting
noname relations. With this change, the 'noname table' support in heap.c
is dead code, and I have accordingly removed it. Also clean up 'noname'
plan handling in planner --- nonames are either sort or materialize plans,
and it seems less confusing to handle them separately under those names.
discussion of 5/19/00). pg_index is now searched for indexes of a
relation using an indexscan. Moreover, this is done once and cached
in the relcache entry for the relation, in the form of a list of OIDs
for the indexes. This list is used by the parser and executor to drive
lookups in the pg_index syscache when they want to know the properties
of the indexes. Net result: index information will be fully cached
for repetitive operations such as inserts.
pointers, namely the catcache tuple fetch routines. Also get rid of
the unused and possibly confusing 'size' field in struct cachedesc.
Since it doesn't allow for variable-length fields, anyone who
actually trusted it would likely be making a mistake...
over multiple lookups --- it should use SearchSysCacheTupleCopy instead.
This accounts for rare failures like 'init_fcache: null probin for procedure 481'
when running concurrently with a VACUUM.
inputs have been converted to newstyle. This should go a long way towards
fixing our portability problems with platforms where char and short
parameters are passed differently from int-width parameters. Still
more to do for the Alpha port however.
key call sites are changed, but most called functions are still oldstyle.
An exception is that the PL managers are updated (so, for example, NULL
handling now behaves as expected in plperl and plpgsql functions).
NOTE initdb is forced due to added column in pg_proc.
really ought to fix relcache entry construction so that it does not
do so much with CurrentMemoryContext = CacheCxt. As is, relatively
harmless leaks in either sequential or index scanning translate to
permanent leaks if they occur when called from relcache build.
For the moment, however, the path of least resistance is to repair
all such leaks...
pg_internal.init file in-place, which meant that if another backend
started at about the same time, it might read the incomplete file.
init_irels tries to guard against that, but I have now seen a crash
due to reading bad data from a partly-written file. (This may indicate
a kernel bug on my platform? Not sure.) Anyway, clearly the safest
course is to write the new pg_internal.init file under a unique temporary
filename, and rename it into place only after it's all written.
running gcc and HP's cc with warnings cranked way up. Signed vs unsigned
comparisons, routines declared static and then defined not-static,
that kind of thing. Tedious, but perhaps useful...
the cache context, it didn't bother to free the tuple that
CatalogIndexFetchTuple had allocated in the transaction context.
Do enough cache lookups in the same xact, and you start to notice...
syscache and relcache flushes). Relcache entry rebuild now preserves
original tupledesc, rewrite rules, and triggers if possible, so that pointers
to these things remain valid --- if these things change while relcache entry
has positive refcount, we elog(ERROR) to avoid later crash. Arrange for
xact-local rels to be rebuilt when an SI inval message is seen for them,
so that they are updated by CommandCounterIncrement the same as regular rels.
(This is useful because of Hiroshi's recent changes to process our own SI
messages at CommandCounterIncrement time.) This allows simplification of
some routines that previously hacked around the lack of an automatic update.
catcache now keeps its own copy of tupledesc for its relation, rather than
depending on the relcache's copy; this avoids needing to reinitialize catcache
during a cache flush, which saves some cycles and eliminates nasty circularity
problems that occur if a cache flush happens while trying to initialize a
catcache.
Eliminate a number of permanent memory leaks that used to happen during
catcache or relcache flush; not least of which was that catcache never
freed any cached tuples! (Rule parsetree storage is still leaked, however;
will fix that separately.)
Nothing done yet about code that uses tuples retrieved by SearchSysCache
for longer than is safe.
we *always* rebuild, rather than deleting, an invalidated relcache entry
that has positive refcount. Otherwise an SI cache overrun leads to
dangling Relation pointers all over the place!
an attribute of a tuple previously fetched with SearchSysCacheTuple.
This avoids a lot of redundant cache lookups, particularly in selfuncs.c.
Also, remove SearchSysCacheStruct, which was unused and grotty.
relcache entry no longer leaks a small amount of memory. index_endscan
now releases all the memory acquired by index_beginscan, so callers of it
should NOT pfree the scan descriptor anymore.
Make all system indexes unique.
Make all cache loads use system indexes.
Rename *rel to *relid in inheritance tables.
Rename cache names to be clearer.
inval.c thought it could safely use the catcache to look up the OIDs of
system relations. Not good, considering that inval.c could be called
during catcache loading, if a shared-inval message arrives. Rip out the
lookup logic and instead use the known OIDs from pg_class.h.
Tom Lane
Alvaro Herrera
Peter Eisentraut
Bruce Momjian
Jan Wieck
Neil Conway
PostgreSQL Daemon
Tatsuo Ishii
Hiroshi Inoue
Vadim B. Mikheev