Bruce Momjian [Mon, 27 Sep 1999 03:13:16 +0000 (03:13 +0000)]
Lots of patches coming in from me today :-)
When drawing up a very simple "text-drawing" of how the negotiation is done,
I realised I had done this last part (fallback) in a very stupid way. Patch
#4 fixes this, and does it in a much better way.
Included is also the simple text-drawing of how the negotiation is done.
Tom Lane [Sun, 26 Sep 1999 21:21:15 +0000 (21:21 +0000)]
Modify nodeAgg.c so that no rows are returned for a GROUP BY
with no input rows, per pghackers discussions around 7/22/99. Clean up
a bunch of ugly coding while at it; remove redundant re-lookup of
aggregate info at start of each new GROUP. Arrange to pfree intermediate
values when they are pass-by-ref types, so that aggregates on pass-by-ref
types no longer eat memory. This takes care of a couple of TODO items...
Tom Lane [Sun, 26 Sep 1999 02:28:44 +0000 (02:28 +0000)]
Implement constant-expression simplification per Bernard
Frankpitt, plus some improvements from yours truly. The simplifier depends
on the proiscachable field of pg_proc to tell it whether a function is
safe to pre-evaluate --- things like nextval() are not, for example.
Update pg_proc.h to contain reasonable cacheability information; as of
6.5.* hardly any functions were marked cacheable. I may have erred too
far in the other direction; see recent mail to pghackers for more info.
This update does not force an initdb, exactly, but you won't see much
benefit from the simplifier until you do one.
Tom Lane [Fri, 24 Sep 1999 00:25:33 +0000 (00:25 +0000)]
Several changes here, not very related but touching some of the same files.
* Buffer refcount cleanup (per my "progress report" to pghackers, 9/22).
* Add links to backend PROC structs to sinval's array of per-backend info,
and use these links for routines that need to check the state of all
backends (rather than the slow, complicated search of the ShmemIndex
hashtable that was used before). Add databaseOID to PROC structs.
* Use this to implement an interlock that prevents DESTROY DATABASE of
a database containing running backends. (It's a little tricky to prevent
a concurrently-starting backend from getting in there, since the new
backend is not able to lock anything at the time it tries to look up
its database in pg_database. My solution is to recheck that the DB is
OK at the end of InitPostgres. It may not be a 100% solution, but it's
a lot better than no interlock at all...)
* In ALTER TABLE RENAME, flush buffers for the relation before doing the
rename of the physical files, to ensure we don't get failures later from
mdblindwrt().
* Update TRUNCATE patch so that it actually compiles against current
sources :-(.
You should do "make clean all" after pulling these changes.
Bruce Momjian [Thu, 23 Sep 1999 19:11:09 +0000 (19:11 +0000)]
One last missing quoting bug in pg_dump:
now that sequence names are properly quoted for field defaults, mixed
case sequence names are generated. These are properly quoted in the
CREATE SEQUENCE lines, but not in the SELECT nextval lines, as per
below:
Tom Lane [Sun, 19 Sep 1999 17:20:58 +0000 (17:20 +0000)]
Remove incorrect 'Assert(targetList != NULL)'. An
INSERT ... DEFAULT VALUES statement does indeed have a null targetlist,
at least during parse and rewrite stages.
Tom Lane [Sat, 18 Sep 1999 19:10:19 +0000 (19:10 +0000)]
Update regress test expected outputs for small changes in
error message wording, due to most cases of no-such-relation now being
detected in central heap_open code rather than on an ad-hoc basis.
Tom Lane [Sat, 18 Sep 1999 19:08:25 +0000 (19:08 +0000)]
Mega-commit to make heap_open/heap_openr/heap_close take an
additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing). Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM. Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing). A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long. Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.
Hiroshi Inoue wrote:
>
> Hello Vadim,
>
> I have a question about vacuum.
>
> VACUUM has a phase like commit which calls TransactionIdCommit().
> But if elog(ERROR) occured after that,the status of transaction is
> changed from XID_COMMIT to XID_ABORT.
>
> Seems to me this causes inconsistency.
> Shoudn't AbortTransaction() be changed not to call TransacionIdAbort()
> in case of vacuum.
Allow CASE statement to contain *only* untyped result clauses or nulls.
Almost worked before, but forgot one place to check.
Reported by Tatsuo Ishii.
Still does not do the right thing if inserting into a non-string target
column. Should look for a type coersion later, but doesn't.
Tom Lane [Mon, 13 Sep 1999 03:00:19 +0000 (03:00 +0000)]
Patch to cure O(N^2) behavior in libpq when reading a long
message under a kernel that only returns one packet per recv() call. This
didn't use to matter much, but it starts to get annoying with multi-megabyte
EXPLAIN VERBOSE responses...
Tom Lane [Mon, 13 Sep 1999 00:17:25 +0000 (00:17 +0000)]
First cut at doing something reasonable with OR-of-ANDs WHERE
conditions. There are some pretty bogus heuristics in prepqual.c that
try to decide whether to output CNF or DNF format; they need to be replaced,
likely. Right now the code is probably too willing to choose DNF form,
which might hurt performance in some cases that used to work OK.
But at least we have a foundation to build on.
Tom Lane [Sun, 12 Sep 1999 18:08:17 +0000 (18:08 +0000)]
Further improvements in cnfify: reduce amount of self-recursion
in or_normalize, remove detection of duplicate subexpressions (since it's
highly unlikely to be worth the amount of time it takes), and introduce
a dnfify() entry point so that unintelligible backwards logic in UNION
processing can be eliminated. This is just an intermediate step ---
next thing is to look at not forcing the qual into CNF form when it would
be better off in DNF form.
Tom Lane [Sat, 11 Sep 1999 22:28:11 +0000 (22:28 +0000)]
Eliminate query length limitation imposed by pg_client_to_server
and pg_server_to_client. Eliminate copy.c's restriction on the length
of a single attribute.
Tom Lane [Sat, 11 Sep 1999 22:02:51 +0000 (22:02 +0000)]
Update protocol doc to emphasize that backend can return
arbitrarily long strings, and frontends should cope gracefully. Goes
along with long query and long error message changes...
Tom Lane [Sat, 11 Sep 1999 19:06:42 +0000 (19:06 +0000)]
Eliminate elog()'s hardwired limit on length of an error message.
This change seems necessary in conjunction with long queries, and it
cleans up some bogosity in connection with long EXPLAIN texts anyway.
Note that current libpq will accept any length error message (at least
until it runs out of memory); prior versions have a limit of 8K, but
will cleanly discard excess error text, so there shouldn't be any
big compatibility problems with old clients.
Tom Lane [Thu, 9 Sep 1999 16:25:35 +0000 (16:25 +0000)]
Repair incorrect cleanup of heap memory allocation during
transaction abort --- before it only worked if there was exactly one level
of allocation context stacked in the blank portal. Now it does the right
thing for any depth, including zero...
Tom Lane [Thu, 9 Sep 1999 02:36:04 +0000 (02:36 +0000)]
Repair error noticed by Roberto Cornacchia: selectivity code
was rejecting negative attnums as bogus, which of course they are not.
Add code to get_attdisbursion to produce a useful value for OID attribute,
since VACUUM does not store stats for system attributes.
Also, repair bug that's been in eqjoinsel for a long time: it was taking
the max of the two columns' disbursions, whereas it should use the min.
Tom Lane [Tue, 7 Sep 1999 03:47:06 +0000 (03:47 +0000)]
Performance improvements in cnfify(): get rid of exponential
space consumption in pull_args, and avoid doing the full CNF transform on
operands of operator clauses, where it's really not particularly helpful.
This answers the TODO item about large numbers of OR clauses, at least
partially. I was able to do a ten-thousand-OR-clause query with about
20Mb memory consumption ... it took an obscenely long time, but it worked...
Tom Lane [Tue, 7 Sep 1999 00:13:27 +0000 (00:13 +0000)]
Mike Ansley's fixes for long queries. This change just
corrects flex myinput() routine so that it doesn't assume there is only
one bufferload of data. We still have the issue of getting rid of
YY_USES_REJECT so that the scanner can cope with tokens larger than its
initial buffer size.
Tom Lane [Mon, 6 Sep 1999 21:16:20 +0000 (21:16 +0000)]
Mark bpchareq not hashjoinable, since it strips trailing blanks
before comparison; if fields being joined are different widths then hashing
will yield wrong answer. Also, remove hashjoinable mark from all uses of
array_eq, because array structures may have padding bytes between elements
and the pad bytes are of uncertain content. This could be revisited if
array code is cleaned up.
Modify opr_sanity regress test to complain if array_eq operator is marked
hashjoinable.
Tom Lane [Mon, 6 Sep 1999 19:37:38 +0000 (19:37 +0000)]
I finally understood what sinvaladt.c is doing --- and it
offended my aesthestic sensibility that there was so much unreadable code
doing so little. Rewritten code is about half the size, faster, and
(I hope) much more intelligible.
Tom Lane [Mon, 6 Sep 1999 19:33:16 +0000 (19:33 +0000)]
Fix relcache.c so that local relations (those created during
current transaction) are not flushed by shared-cache-inval reset message.
SI reset actually works now, for probably the first time in a long time.
I was able to run initdb and regression tests with a 16-element SI message
array, with a lot of NOTICE: cache state reset messages but no crashes.
Tom Lane [Mon, 6 Sep 1999 18:13:02 +0000 (18:13 +0000)]
RelationCacheInvalidate thought there were 7 nailed-in-cache
system tables, but actually there are only 6 --- see RelationInitialize.
Kinda makes you wonder how long ago this code was last executed...
Tom Lane [Sun, 5 Sep 1999 23:24:53 +0000 (23:24 +0000)]
Per Tatsuo's recommendation, change mdopen so that it won't
automatically create the file, except during bootstrap mode where that
seems to be necessary.
Tom Lane [Sun, 5 Sep 1999 17:43:47 +0000 (17:43 +0000)]
Disallow DROP TABLE/DROP INDEX inside a transaction block.
We can't support these properly, since once the relation's physical files
are unlinked, there's no way to roll back the transaction. I suppose
we could postpone the unlink till transaction commit, but then what of
BEGIN; DROP TABLE foo; CREATE TABLE foo; ?
The code does allow dropping a table/index created in the current
transaction block, however, since the post-abort state would be that
the table doesn't exist anyway.
Tom Lane [Sat, 4 Sep 1999 21:47:23 +0000 (21:47 +0000)]
In RelationNameGetRelation(), replace temp table name by
real name before doing lookup. We only want to index temp tables by their
real names in the relcache, to ensure there's not more than one relcache
entry for them.
Tom Lane [Sat, 4 Sep 1999 18:42:15 +0000 (18:42 +0000)]
Modify RelationFlushRelation so that if the relcache entry
has positive refcount, it is rebuilt from pg_class data. This ensures
that relcache entries will track changes made by other backends. Formerly,
a shared inval report would just be ignored if it happened to arrive while
the relcache entry was in use. Also, fix relcache to reset ref counts
to zero during transaction abort. Finally, change LockRelation() so that
it checks for shared inval reports after obtaining the lock. In this way,
once any kind of lock has been obtained on a rel, we can trust the relcache
entry to be up-to-date.
Tom Lane [Sat, 4 Sep 1999 18:36:45 +0000 (18:36 +0000)]
Modify sinval so that InvalidateSharedInvalid() does not hold
the SInval spinlock while it is calling the passed invalFunction or
resetFunction. This is necessary to avoid deadlock with lmgr change;
InvalidateSharedInvalid can be called recursively now. It should be
a good performance improvement anyway --- holding a spinlock for more
than a very short interval is a no-no.