'recycled log files' and 'removed log files' messages from DEBUG1 to
DEBUG2, replacing them with a count of files added/removed/recycled in
the checkpoint end message, as per suggestion from Simon Riggs.
pins at end of transaction, and reduce AtEOXact_Buffers to an Assert
cross-check that this was done correctly. When not USE_ASSERT_CHECKING,
AtEOXact_Buffers is a complete no-op. This gets rid of an O(NBuffers)
bottleneck during transaction commit/abort, which recent testing has shown
becomes significant above a few tens of thousands of shared buffers.
running contains VACUUM or a similar command that will internally start
and commit transactions. In such a case, the original caller values of
CurrentMemoryContext and CurrentResourceOwner will point to objects that
will be destroyed by the internal commit. We must restore these pointers
to point to the newly-manufactured transaction context and resource owner,
rather than possibly pointing to deleted memory.
Also tweak xact.c so that AbortTransaction and AbortSubTransaction
forcibly restore a sane value for CurrentResourceOwner, much as they
have always done for CurrentMemoryContext. I'm not certain this is
necessary but I'm feeling paranoid today.
Responds to Sean Chittenden's bug report of 4-Oct.
pg_subtrans --- what we need is the oldest xmin of any snapshot in use
in the current top transaction. Introduce a new variable TransactionXmin
to play this role. Fixes intermittent regression failure reported by
Neil Conway.
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.
mode see a fresh snapshot for each command in the function, rather than
using the latest interactive command's snapshot. Also, suppress fresh
snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE
functions, instead using the snapshot taken for the most closely nested
regular query. (This behavior is only sane for read-only functions, so
the patch also enforces that such functions contain only SELECT commands.)
As per my proposal of 6-Sep-2004; I note that I floated essentially the
same proposal on 19-Jun-2002, but that discussion tailed off without any
action. Since 8.0 seems like the right place to be taking possibly
nontrivial backwards compatibility hits, let's get it done now.
rather than when returning to the idle loop. This makes no particular
difference for interactively-issued queries, but it makes a big difference
for queries issued within functions: trigger execution now occurs before
the calling function is allowed to proceed. This responds to numerous
complaints about nonintuitive behavior of foreign key checking, such as
http://archives.postgresql.org/pgsql-bugs/2004-09/msg00020.php, and
appears to be required by the SQL99 spec.
Also take the opportunity to simplify the data structures used for the
pending-trigger list, rename them for more clarity, and squeeze out a
bit of space.
Fix TablespaceCreateDbspace() to be able to create a dummy directory
in place of a dropped tablespace's symlink. This eliminates the open
problem of a PANIC during WAL replay when a replayed action attempts
to touch a file in a since-deleted tablespace. It also makes for a
significant improvement in the usability of PITR replay.
a more tolerable limit on the number of subtransactions or deleted files
in COMMIT and ABORT records. Buy back the extra space by eliminating the
xl_xact_prev field, which isn't being used for anything and is rather
unlikely ever to be used for anything.
This does not force initdb, but you do need to do pg_resetxlog if you
want to upgrade an existing 8.0 installation without initdb.
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.
for every command executed within a transaction. For long transactions
this was a significant memory leak. Instead, we can delete a portal's
or subtransaction's ResourceOwner immediately, if we physically transfer
the information about its locks up to the parent owner. This does not
fully solve the leak problem; we need to do something about counting
multiple acquisitions of the same lock in order to fix it. But it's a
necessary step along the way.
updates are no longer WAL-logged nor even fsync'd; we do not need to,
since after a crash no old pg_subtrans data is needed again. We truncate
pg_subtrans to RecentGlobalXmin at each checkpoint. slru.c's API is
refactored a little bit to separate out the necessary decisions.
RecentXmin (== MyProc->xmin). This ensures that it will be safe to
truncate pg_subtrans at RecentGlobalXmin, which should largely eliminate
any fear of bloat. Along the way, eliminate SubTransXidsHaveCommonAncestor,
which isn't really needed and could not give a trustworthy result anyway
under the lookback restriction.
In an unrelated but nearby change, #ifdef out GetUndoRecPtr, which has
been dead code since 2001 and seems unlikely to ever be resurrected.
and doesn't process forward slashes in the same way as external
commands. Quoting the first argument to COPY does not convert forward
to backward slashes, but COPY does properly process quoted forward
slashes in the second argument.
Win32 COPY works with quoted forward slashes in the first argument only if the
current directory is the same as the directory of the first argument.
for transaction commits that occurred just before the checkpoint. This is
an EXTREMELY serious bug --- kudos to Satoshi Okada for creating a
reproducible test case to prove its existence.
slashes to backslashes #ifdef WIN32. This is to cope with the fact
that Windows seems exceedingly unfriendly to slashes in shell commands,
as per recent discussion.
and history files as per recent discussion. While at it, remove
pg_terminate_backend, since we have decided we do not have time during
this release cycle to address the reliability concerns it creates.
Split the 'Miscellaneous Functions' documentation section into
'System Information Functions' and 'System Administration Functions',
which hopefully will draw the eyes of those looking for such things.
number of active subtransaction XIDs in each backend's PGPROC entry,
and use this to avoid expensive probes into pg_subtrans during
TransactionIdIsInProgress. Extend EOXactCallback API to allow add-on
modules to get control at subxact start/end. (This is deliberately
not compatible with the former API, since any uses of that API probably
need manual review anyway.) Add basic reference documentation for
SAVEPOINT and related commands. Minor other cleanups to check off some
of the open issues for subtransactions.
Alvaro Herrera and Tom Lane.
There are still some things that need refinement; in particular I fear
that the recognized set of error condition names probably has little in
common with what Oracle recognizes. But it's a start.
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.
SAVEPOINT/RELEASE/ROLLBACK-TO syntax. (Alvaro)
Cause COMMIT of a failed transaction to report ROLLBACK instead of
COMMIT in its command tag. (Tom)
Fix a few loose ends in the nested-transactions stuff.
recovery_target_timeline --- otherwise there is no path from the backup
to the requested timeline. This check was foreseen in the original
discussion but I forgot to implement it.
recovered from archive is not corrupt. It's not much but it will catch
one common problem, viz out-of-disk-space.
Also, force a WAL recovery scan when recovery.conf is present, even if
pg_control shows a clean shutdown. This allows recovery with a tar backup
that was taken with the postmaster shut down, as per complaint from
Mark Kirkwood.
recovery more manageable. Also, undo recent change to add FILE_HEADER
and WASTED_SPACE records to XLOG; instead make the XLOG page header
variable-size with extra fields in the first page of an XLOG file.
This should fix the boundary-case bugs observed by Mark Kirkwood.
initdb forced due to change of XLOG representation.
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.
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.
place of time_t, as per prior discussion. The behavior does not change
on machines without a 64-bit-int type, but on machines with one, which
is most, we are rid of the bizarre boundary behavior at the edges of
the 32-bit-time_t range (1901 and 2038). The system will now treat
times over the full supported timestamp range as being in your local
time zone. It may seem a little bizarre to consider that times in
4000 BC are PST or EST, but this is surely at least as reasonable as
propagating Gregorian calendar rules back that far.
I did not modify the format of the zic timezone database files, which
means that for the moment the system will not know about daylight-savings
periods outside the range 1901-2038. Given the way the files are set up,
it's not a simple decision like 'widen to 64 bits'; we have to actually
think about the range of years that need to be supported. We should
probably inquire what the plans of the upstream zic people are before
making any decisions of our own.
explicitly fsync'ing every (non-temp) file we have written since the
last checkpoint. In the vast majority of cases, the burden of the
fsyncs should fall on the bgwriter process not on backends. (To this
end, we assume that an fsync issued by the bgwriter will force out
blocks written to the same file by other processes using other file
descriptors. Anyone have a problem with that?) This makes the world
safe for WIN32, which ain't even got sync(2), and really makes the world
safe for Unixen as well, because sync(2) never had the semantics we need:
it offers no way to wait for the requested I/O to finish.
Along the way, fix a bug I recently introduced in xlog recovery:
file truncation replay failed to clear bufmgr buffers for the dropped
blocks, which could result in 'PANIC: heap_delete_redo: no block'
later on in xlog replay.
than being random pieces of other files. Give bgwriter responsibility
for all checkpoint activity (other than a post-recovery checkpoint);
so this child process absorbs the functionality of the former transient
checkpoint and shutdown subprocesses. While at it, create an actual
include file for postmaster.c, which for some reason never had its own
file before.
about a third, make it work on non-Windows platforms again. (But perhaps
I broke the WIN32 code, since I have no way to test that.) Fold all the
paths that fork postmaster child processes to go through the single
routine SubPostmasterMain, which takes care of resurrecting the state that
would normally be inherited from the postmaster (including GUC variables).
Clean up some places where there's no particularly good reason for the
EXEC and non-EXEC cases to work differently. Take care of one or two
FIXMEs that remained in the code.
of ThisStartUpID and RedoRecPtr into new backends. It's a lot easier just
to make them all grab the values out of shared memory during startup.
This helps to decouple the postmaster from checkpoint execution, which I
need since I'm intending to let the bgwriter do it instead, and it also
fixes a bug in the Win32 port: ThisStartUpID wasn't getting propagated at
all AFAICS. (Doesn't give me a lot of faith in the amount of testing that
port has gotten.)
and should do now that we control our own destiny for timezone handling,
but this commit gets the bulk of the picayune diffs in place.
Magnus Hagander and Tom Lane.
conversion of basic ASCII letters. Remove all uses of strcasecmp and
strncasecmp in favor of new functions pg_strcasecmp and pg_strncasecmp;
remove most but not all direct uses of toupper and tolower in favor of
pg_toupper and pg_tolower. These functions use the same notions of
case folding already developed for identifier case conversion. I left
the straight locale-based folding in place for situations where we are
just manipulating user data and not trying to match it to built-in
strings --- for example, the SQL upper() function is still locale
dependent. Perhaps this will prove not to be what's wanted, but at
the moment we can initdb and pass regression tests in Turkish locale.
* removed a few redundant defines
* get_user_name safe under win32
* rationalized pipe read EOF for win32 (UPDATED PATCH USED)
* changed all backend instances of sleep() to pg_usleep
- except for the SLEEP_ON_ASSERT in assert.c, as it would exceed a
32-bit long [Note to patcher: If a SLEEP_ON_ASSERT of 2000 seconds is
acceptable, please replace with pg_usleep(2000000000L)]
I added a comment to that part of the code:
/*
* It would be nice to use pg_usleep() here, but only does 2000 sec
* or 33 minutes, which seems too short.
*/
sleep(1000000);
Claudio Natoli
and FreeDir routines modeled on the existing AllocateFile/FreeFile.
Like the latter, these routines will avoid failing on EMFILE/ENFILE
conditions whenever possible, and will prevent leakage of directory
descriptors if an elog() occurs while one is open.
Also, reduce PANIC to ERROR in MoveOfflineLogs() --- this is not
critical code and there is no reason to force a DB restart on failure.
All per recent trouble report from Olivier Hubaut.
1) Now puts in exactly the same change as the current-cvs mingw code
does. (see
http://cvs.sourceforge.net/viewcvs.py/mingw/runtime/mingwex/dirent.c?r1=
1.3&r2=1.4, second part of the patch).
2) Updates both xlog.c and slru.c in backend/access/transam/
3) Also updates pg_resetxlog, which also uses readdir() and checks the
errno value after the loop.
Magnus Hagander
wit: Add a header record to each WAL segment file so that it can be reliably
identified. Avoid splitting WAL records across segment files (this is not
strictly necessary, but makes it simpler to incorporate the header records).
Make WAL entries for file creation, deletion, and truncation (as foreseen but
never implemented by Vadim). Also, add support for making XLOG_SEG_SIZE
configurable at compile time, similarly to BLCKSZ. Fix a couple bugs I
introduced in WAL replay during recent smgr API changes. initdb is forced
due to changes in pg_control contents.
subroutine in src/port/pgsleep.c. Remove platform dependencies from
miscadmin.h and put them in port.h where they belong. Extend recent
vacuum cost-based-delay patch to apply to VACUUM FULL, ANALYZE, and
non-btree index vacuuming.
By the way, where is the documentation for the cost-based-delay patch?
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.
whereToSendOutput instead because they are really inquiring about
the correct client communication protocol. Update some comments.
This is pointing towards supporting regular FE/BE client protocol
in a standalone backend, per discussion a month or so back.
complete ExtendCLOG() before advancing nextXid, so that if that routine
fails, the next incoming transaction will try it again. Per trouble
report from Christopher Kings-Lynne.
should not be too eager to reject paths involving unknown schemas, since
it can't really tell whether the schemas exist in the target database.
(Also, when reading pg_dumpall output, it could be that the schemas
don't exist yet, but eventually will.) ALTER USER SET has a similar issue.
So, reduce the normal ERROR to a NOTICE when checking search_path values
for these commands. Supporting this requires changing the API for GUC
assign_hook functions, which causes the patch to touch a lot of places,
but the changes are conceptually trivial.
pointer type when it is not necessary to do so.
For future reference, casting NULL to a pointer type is only necessary
when (a) invoking a function AND either (b) the function has no prototype
OR (c) the function is a varargs function.
some concurrent changes Jan was making to the bufmgr. Here's an
updated version of the patch -- it should apply cleanly to CVS
HEAD and passes the regression tests.
This patch makes the following changes:
- remove the UnlockAndReleaseBuffer() and UnlockAndWriteBuffer()
macros, and replace uses of them with calls to the appropriate
functions.
- remove a bunch of #ifdef BMTRACE code: it is ugly & broken
(i.e. it doesn't compile)
- make BufferReplace() return a bool, not an int
- cleanup some logic in bufmgr.c; should be functionality
equivalent to the previous code, just cleaner now
- remove the BM_PRIVATE flag as it is unused
- improve a few comments, etc.
protocol, per report from Igor Shevchenko. NOTIFY thought it could
do its thing if transaction blockState is TBLOCK_DEFAULT, but in
reality it had better check the low-level transaction state is
TRANS_DEFAULT as well. Formerly it was not possible to wait for the
client in a state where the first is true and the second is not ...
but now we can have such a state. Minor cleanup in StartTransaction()
as well.
post-abort cleanup hooks. I'm surprised that we have not needed this
already, but I need it now to fix a plpgsql problem, and the usefulness
for other dynamically loaded modules seems obvious.
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.
fixed incorrect initial setting of StartUpID. The logic in XLogWrite()
expects that Write->curridx is advanced to the next page as soon as
LogwrtResult points to the end of the current page, but StartupXLOG()
failed to make that happen when the old WAL ended exactly on a page
boundary. Per trouble report from Hannu Krosing.
least-recently-used strategy from clog.c into slru.c. It doesn't
change any visible behaviour and passes all regression tests plus a
TruncateCLOG test done manually.
Apart from refactoring I made a little change to SlruRecentlyUsed,
formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if
slotno is already the LRU slot, thus saving a few CPU cycles. To make
this work, lru_counts are initialised to 1 in SimpleLruInit.
SimpleLru will be used by pg_subtrans (part of the nested transactions
project), so the main purpose of this patch is to avoid future code
duplication.
Manfred Koizar
example from Rao Kumar. This is a very corner corner-case, requiring
a minimum of three closely-spaced database crashes and an unlucky
positioning of the second recovery's checkpoint record before you'd notice
any problem. But the consequences are dire enough that it's a must-fix.
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON. Still TODO: provide some client-side autocommit
logic in libpq.
dead xlog segments are not considered part of a critical section. It is
not necessary to force a database-wide panic if we get a failure in these
operations. Per recent trouble reports.
Both plannable queries and utility commands are now always executed
within Portals, which have been revamped so that they can handle the
load (they used to be good only for single SELECT queries). Restructure
code to push command-completion-tag selection logic out of postgres.c,
so that it won't have to be duplicated between simple and extended queries.
initdb forced due to addition of a field to Query nodes.
for tableID/columnID in RowDescription. (The latter isn't really
implemented yet though --- the backend always sends zeroes, and libpq
just throws away the data.)
initial values and runtime changes in selected parameters. This gets
rid of the need for an initial 'select pg_client_encoding()' query in
libpq, bringing us back to one message transmitted in each direction
for a standard connection startup. To allow server version to be sent
using the same GUC mechanism that handles other parameters, invent the
concept of a never-settable GUC parameter: you can 'show server_version'
but it's not settable by any GUC input source. Create 'lc_collate' and
'lc_ctype' never-settable parameters so that people can find out these
settings without need for pg_controldata. (These side ideas were all
discussed some time ago in pgsql-hackers, but not yet implemented.)
(materialization into a tuple store) discussed on pgsql-hackers earlier.
I've updated the documentation and the regression tests.
Notes on the implementation:
- I needed to change the tuple store API slightly -- it assumes that it
won't be used to hold data across transaction boundaries, so the temp
files that it uses for on-disk storage are automatically reclaimed at
end-of-transaction. I added a flag to tuplestore_begin_heap() to control
this behavior. Is changing the tuple store API in this fashion OK?
- in order to store executor results in a tuple store, I added a new
CommandDest. This works well for the most part, with one exception: the
current DestFunction API doesn't provide enough information to allow the
Executor to store results into an arbitrary tuple store (where the
particular tuple store to use is chosen by the call site of
ExecutorRun). To workaround this, I've temporarily hacked up a solution
that works, but is not ideal: since the receiveTuple DestFunction is
passed the portal name, we can use that to lookup the Portal data
structure for the cursor and then use that to get at the tuple store the
Portal is using. This unnecessarily ties the Portal code with the
tupleReceiver code, but it works...
The proper fix for this is probably to change the DestFunction API --
Tom suggested passing the full QueryDesc to the receiveTuple function.
In that case, callers of ExecutorRun could "subclass" QueryDesc to add
any additional fields that their particular CommandDest needed to get
access to. This approach would work, but I'd like to think about it for
a little bit longer before deciding which route to go. In the mean time,
the code works fine, so I don't think a fix is urgent.
- (semi-related) I added a NO SCROLL keyword to DECLARE CURSOR, and
adjusted the behavior of SCROLL in accordance with the discussion on
-hackers.
- (unrelated) Cleaned up some SGML markup in sql.sgml, copy.sgml
Neil Conway
support btree compaction, as per proposal of a few days ago. btree index
pages no longer store parent links, instead they have a level indicator
(counting up from zero for leaf pages). The FixBTree recovery logic is
removed, and replaced by code that detects missing parent-level insertions
during WAL replay. Also, generate appropriate WAL entries when updating
btree metapage and when building a btree index from scratch. I believe
btree indexes are now completely WAL-legal for the first time.
initdb forced due to index and WAL changes.
rather than actually opening the files. This eliminates some corner cases
where the file indeed exists but open() fails for another reason, such
as being out of file descriptors. The net reliability gain is probably
tiny, since xlog.c is full of other file open calls that will elog(PANIC)
if they fail for any reason; but this specific failure mode has been
observed in the field, so we may as well fix it.
-hackers a couple days ago.
Notes/caveats:
- added regression tests for the new functionality, all
regression tests pass on my machine
- added pg_dump support
- updated PL/PgSQL to support per-statement triggers; didn't
look at the other procedural languages.
- there's (even) more code duplication in trigger.c than there
was previously. Any suggestions on how to refactor the
ExecXXXTriggers() functions to reuse more code would be
welcome -- I took a brief look at it, but couldn't see an
easy way to do it (there are several subtly-different
versions of the code in question)
- updated the documentation. I also took the liberty of
removing a big chunk of duplicated syntax documentation in
the Programmer's Guide on triggers, and moving that
information to the CREATE TRIGGER reference page.
- I also included some spelling fixes and similar small
cleanups I noticed while making the changes. If you'd like
me to split those into a separate patch, let me know.
Neil Conway
before commit, not after :-( --- the original coding is not only unsafe
if an error occurs while it's processing, but it generates an invalid
sequence of WAL entries. Resurrect 7.2 logic for deleting items when
no longer needed. Use an enum instead of random macros. Editorialize
on names used for routines and constants. Teach backend/nodes routines
about new field in CreateTable struct. Add a regression test.
postgres.h or c.h includes a system header (such as stdio.h or
stdlib.h), there's no need to specifically include it in any of the .c
files in the backend.
Neil Conway
principled order; in particular ensure that all shared resources
are released before we release transaction locks. The code used
to release locks before buffer pins, which might explain an ancient
note I have about a bufmgr assertion failure I'd seen once several
years ago, and been unable to reproduce since. (Theory: someone
trying to drop a relation might be able to reach FlushRelationBuffers
before the last user of the relation had gotten around to dropping
his buffer pins.)
in our write/flush operation any WAL entries that got queued while we
were waiting to get the WALWriteLock. This improves throughput when
transactions are small enough that several can be committed per WAL
write (ie, per disk revolution).
to false provides more SQL-spec-compliant behavior than we had before.
I am not sure that setting it false is actually a good idea yet; there
is a lot of client-side code that will probably be broken by turning
autocommit off. But it's a start.
Loosely based on a patch by David Van Wie.
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.
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.
HeapTupleHeaderData in setter and getter macros called
HeapTupleHeaderGetXmin, HeapTupleHeaderSetXmin etc.
It also introduces a "virtual" field xvac by defining
HeapTupleHeaderGetXvac and HeapTupleHeaderSetXvac. Xvac is used by
VACUUM, in fact it is stored in t_cmin.
Manfred Koizar
> Changes to avoid collisions with WIN32 & MFC names...
> 1. Renamed:
> a. PROC => PGPROC
> b. GetUserName() => GetUserNameFromId()
> c. GetCurrentTime() => GetCurrentDateTime()
> d. IGNORE => IGNORE_DTF in include/utils/datetime.h & utils/adt/datetim
>
> 2. Added _P to some lex/yacc tokens:
> CONST, CHAR, DELETE, FLOAT, GROUP, IN, OUT
Jan
exemplified by bug #671. Moving the storage to relcache turned out to
be a bad idea because relcache might decide to discard the info. Instead,
open and close the relcache entry on each sequence operation, and use
a record of the current XID to discover whether we already hold
AccessShareLock on the sequence.
in snapshots, per my proposal of a few days ago. Also, tweak heapam.c
routines (heap_insert, heap_update, heap_delete, heap_mark4update) to
be passed the command ID to use, instead of doing GetCurrentCommandID.
For catalog updates they'll still get passed current command ID, but
for updates generated from the main executor they'll get passed the
command ID saved in the snapshot the query is using. This should fix
some corner cases associated with functions and triggers that advance
current command ID while an outer query is still in progress.
allows the example in the CREATE SCHEMA ref page to actually work now.
Also, clean up when the transaction that initially creates a temp-table
namespace is later aborted. Simplify internal representation of search
path by folding special cases into the main list.
GUC support. It's now possible to set datestyle, timezone, and
client_encoding from postgresql.conf and per-database or per-user
settings. Also, implement rollback of SET commands that occur in a
transaction that later fails. Create a SET LOCAL var = value syntax
that sets the variable only for the duration of the current transaction.
All per previous discussions in pghackers.
compiled for integer date/time storage and to check the length of
storage for the locale fields in the same data structure.
Slightly reword some of the error messages to be more accurate on
possible recovery options (e.g. recompile *or* re-initdb).
Bump version number on this file.
path. The default behavior if no per-user schemas are created is that
all users share a 'public' namespace, thus providing behavior backwards
compatible with 7.2 and earlier releases. Probably the semantics and
default setting will need to be fine-tuned, but this is a start.
per recent pghackers discussion: force a new WAL record at first nextval
after a checkpoint, and ensure that xlog is flushed to disk if a nextval
record is the only thing emitted by a transaction.
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.
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
per my proposal of a couple days ago. This will eliminate the unable-
to-restart-database class of problem that we have seen reported half a
dozen times with 7.1.*.
'volatile' pointers to access those structures, so that optimizing
compilers will not decide to move the structure accesses outside of the
spinlock-acquire-to-spinlock-release sequence. There are no known bugs
in these uses at present, but based on bad experience with lwlock.c,
it seems prudent to ensure that we protect these other uses too.
Per pghackers discussion around 12-Dec. (Note: it should not be
necessary to worry about structures protected by LWLocks, since the
LWLock acquire and release operations are not inline macros.)
do not use the undo pointer anyway. This is a quick-hack solution for
the three-way deadlock condition discussed in pghackers 17-Dec-01.
Need to find a better way of doing it.
so that only one signal number is used not three. Flags in shared
memory tell the reason(s) for the current signal. This method is
extensible to handle more signal reasons without chewing up even more
signal numbers, but the immediate reason is to keep pg_pwd reloads
separate from SIGHUP processing in the postmaster.
Also clean up some problems in the postmaster with delayed response to
checkpoint status changes --- basically, it wouldn't schedule a checkpoint
if it wasn't getting connection requests on a regular basis.
Modified the parser and the SET handlers to use full Node structures
rather than simply a character string argument.
Implement INTERVAL() YEAR TO MONTH (etc) syntax per SQL99.
Does not yet accept the goofy string format that goes along with, but
this should be fairly straight forward to fix now as a bug or later
as a feature.
Implement precision for the INTERVAL() type.
Use the typmod mechanism for both of INTERVAL features.
Fix the INTERVAL syntax in the parser:
opt_interval was in the wrong place.
INTERVAL is now a reserved word, otherwise we get reduce/reduce errors.
Implement an explicit date_part() function for TIMETZ.
Should fix coersion problem with INTERVAL reported by Peter E.
Fix up some error messages for date/time types.
Use all caps for type names within message.
Fix recently introduced side-effect bug disabling 'epoch' as a recognized
field for date_part() etc. Reported by Peter E. (??)
Bump catalog version number.
Rename "microseconds" current transaction time field
from ...Msec to ...Usec. Duh!
date/time regression tests updated for reference platform, but a few
changes will be necessary for others.
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.
existing lock manager and spinlocks: it understands exclusive vs shared
lock but has few other fancy features. Replace most uses of spinlocks
with lightweight locks. All remaining uses of spinlocks have very short
lock hold times (a few dozen instructions), so tweak spinlock backoff
code to work efficiently given this assumption. All per my proposal on
pghackers 26-Sep-01.
Define a new function, GetCurrentTransactionStartTimeUsec() to get the time
to this precision.
Allow now() and timestamp 'now' to use this higher precision result so
we now have fractional seconds in this "constant".
Add timestamp without time zone type.
Move previous timestamp type to timestamp with time zone.
Accept another ISO variant for date/time values: yyyy-mm-ddThh:mm:ss
(note the "T" separating the day from hours information).
Remove 'current' from date/time types; convert to 'now' in input.
Separate time and timetz regression tests.
Separate timestamp and timestamptz regression test.
Standardize on %X/%X as the formatting for XLOG position display --- we
had a couple of different formats before, and none of 'em were as useful
as hex offsets IMHO.
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.
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.
rather than deleting them only to have to create more. Steady state
is 2*CHECKPOINT_SEGMENTS + WAL_FILES + 1 segment files, which will
simply be renamed rather than constantly deleted and recreated.
To make this safe, added current XLOG file/offset number to page
header of XLOG pages, so that an un-overwritten page from an old
incarnation of a logfile can be reliably told from a valid page.
This change means that if you try to restart postmaster in a CVS-tip
database after installing the change, you'll get a complaint about
bad XLOG page magic number. If you don't want to initdb, run
contrib/pg_resetxlog (and be sure you shut down the old postmaster
cleanly).
in GetSnapshotData, GetNewTransactionId, CommitTransaction, AbortTransaction,
etc. Correct race condition in transaction status testing in
HeapTupleSatisfiesVacuum --- this wasn't important for old VACUUM with
exclusive lock on its table, but it sure is important now. All per
pghackers discussion 7/11/01 and 7/12/01.
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
validity checking rules for VACUUM. Make some other rearrangements of the
VACUUM code to allow more code to be shared between full and lazy VACUUM.
Minor code cleanups and added comments for TransactionId manipulations.
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.
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.
checkpoint's redo pointer, not its undo pointer, per discussion in
pghackers a few days ago. No point in hanging onto undo information
until we have the ability to do something with it --- and this solves
a rather large problem with log space for long-running transactions.
Also, change all calls of write() to detect the case where write
returned a count less than requested, but failed to set errno.
Presume that this situation indicates ENOSPC, and give the appropriate
error message, rather than a random message associated with the previous
value of errno.
Python) to support shared extension modules, I have learned that Guido
prefers the style of the attached patch to solve the above problem.
I feel that this solution is particularly appropriate in this case
because the following:
PglargeType
PgType
PgQueryType
are already being handled in the way that I am proposing for PgSourceType.
Jason Tishler
O_SYNC, or O_DSYNC (as available on a given platform). Add GUC parameter
to control sync method.
Also, add defense to XLogWrite to prevent it from going nuts if passed
a target write position that's past the end of the buffers so far filled
by XLogInsert.
detect case that next page in log came from an older run than the prior
page. This avoids the necessity to re-zero the log after recovery from
a crash, which is good because we need not risk destroying valuable log
information.
This forces another initdb since yesterday :-(. Need to get that log
reset utility done...
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
only if at least N other backends currently have open transactions. This
is not a great deal of intelligence about whether a delay might be
profitable ... but it beats no intelligence at all. Note that the default
COMMIT_DELAY is still zero --- this new code does nothing unless that
setting is changed.
Also, mark ENABLEFSYNC as a system-wide setting. It's no longer safe to
allow that to be set per-backend, since we may be relying on some other
backend's fsync to have synced the WAL log.
waste of cycles on single-CPU machines, and of dubious utility on multi-CPU
machines too.
Tweak s_lock_stuck so that caller can specify timeout interval, and
increase interval before declaring stuck spinlock for buffer locks and XLOG
locks.
On systems that have fdatasync(), use that rather than fsync() to sync WAL
log writes. Ensure that WAL file is entirely allocated during XLogFileInit.
are treated more like 'cancel' interrupts: the signal handler sets a
flag that is examined at well-defined spots, rather than trying to cope
with an interrupt that might happen anywhere. See pghackers discussion
of 1/12/01.
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().
- no more elog(STOP) in StartupXLOG();
- both checkpoint' undo & redo are used to define
oldest on-line log file.
2. Ability to pre-allocate a few log files at checkpoint time
(wal_files option). Off by default.
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.
assume that TAS() will always succeed the first time, even if the lock
is known to be free. Also, make sure that code will eventually time out
and report a stuck spinlock, rather than looping forever. Small cleanups
in s_lock.h, too.
level" locks. A session lock is not released at transaction commit (but it
is released on transaction abort, to ensure recovery after an elog(ERROR)).
In VACUUM, use a session lock to protect the master table while vacuuming a
TOAST table, so that the TOAST table can be done in an independent
transaction.
I also took this opportunity to do some cleanup and renaming in the lock
code. The previously noted bug in ProcLockWakeup, that it couldn't wake up
any waiters beyond the first non-wakeable waiter, is now fixed. Also found
a previously unknown bug of the same kind (failure to scan all members of
a lock queue in some cases) in DeadLockCheck. This might have led to failure
to detect a deadlock condition, resulting in indefinite waits, but it's
difficult to characterize the conditions required to trigger a failure.
>> xlog.c : special case for beos to avoid 'link' which does not work yet
>> beos/sem.c : implementation of new sem_ctl call (GETPID) and a new
>sem_op
>> flag (IPCNOWAIT)
>> dynloader/beos.c : add a verification of symbol validity (seem that
the
>> loader sometime return OK with an invalid symbol)
>> postmaster.c : add beos forking support for the new checkpoint
process
>> postgres.c : remove beos special case for getrusage
>> beos.h : Correction of a bas definition of AF_UNIX, misc defnitions
>>
>>
>> thanks
>>
>>
>> cyril
Cyril VELTER
to ensure that we have released buffer refcounts and so forth, rather than
putting ad-hoc operations before (some of the calls to) proc_exit. Add
commentary to discourage future hackers from repeating that mistake.
IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c. TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.
re-adopt these settings at every postmaster or standalone-backend startup.
This should fix problems with indexes becoming corrupt due to failure to
provide consistent locale environment for postmaster at all times. Also,
refuse to start up a non-locale-enabled compilation in a database originally
initdb'd with a non-C locale. Suppress LIKE index optimization if locale
is not "C" or "POSIX" (are there any other locales where it's safe?).
Issue NOTICE during initdb if selected locale disables LIKE optimization.
Neil Conway
Peter Eisentraut
Tom Lane
Bruce Momjian
Joe Conway
PostgreSQL Daemon
Thomas G. Lockhart
Jan Wieck
Vadim B. Mikheev
Hiroshi Inoue